Merge pull request #372 from callvirtual/features/sql-transactions-collector

Add support for MSSQL Transactions counters

.gitignore

@@ -2,3 +2,6 @@
 VERSION
 *.swp
 *.un~
+output/
+.vscode
+.idea

.promu.yml

@@ -12,3 +12,7 @@ build:
 tarball:
     files:
         - LICENSE
+crossbuild:
+    platforms:
+        - windows/amd64
+        - windows/386

Gopkg.lock

@@ -37,12 +37,12 @@
   revision = "4c0e84591b9aa9e6dcfdf3e020114cd81f89d5f9"
 
 [[projects]]
-  digest = "1:ec6271918b59b872a2d25e374569a4f75f1839d91e4191470c297b7eaaaf7641"
+  digest = "1:f9adc21a937e5da643ea14a3488cb7506788876737a5e205394e508627a6eec8"
   name = "github.com/dimchansky/utfbom"
   packages = ["."]
   pruneopts = "NUT"
-  revision = "5448fe645cb1964ba70ac8f9f2ffe975e61a536c"
-  version = "v1.0.0"
+  revision = "d2133a1ce379ef6fa992b0514a77146c60db9d1c"
+  version = "v1.1.0"
 
 [[projects]]
   digest = "1:cb4e216bd9f58866f42dc65893455b24f879b026fdaa1ecc3aafff625fdb5a66"

Makefile

@@ -1,5 +1,19 @@
-fmt:
-	gofmt -l -w -s .
+export GOOS=windows
 
 build:
 	promu build -v
+
+test:
+	go test -v ./...
+
+lint:
+	gometalinter --vendor --config gometalinter.config ./...
+
+fmt:
+	gofmt -l -w -s .
+
+crossbuild:
+	# The prometheus/golang-builder image for promu crossbuild doesn't exist
+	# on Windows, so for now, we'll just build twice
+	GOARCH=amd64 promu build --prefix=output/amd64
+	GOARCH=386   promu build --prefix=output/386

README.md

@@ -9,22 +9,32 @@ Prometheus exporter for Windows machines, using the WMI (Windows Management Inst
 
 Name     | Description | Enabled by default
 ---------|-------------|--------------------
-[ad](docs/collector.ad.md) | [Win32_PerfRawData_DirectoryServices_DirectoryServices](https://msdn.microsoft.com/en-us/library/ms803980.aspx) Active Directory |
-[cpu](docs/collector.cpu.md) | [Win32_PerfRawData_PerfOS_Processor](https://msdn.microsoft.com/en-us/library/aa394317(v=vs.90).aspx) metrics (cpu usage) | ✓
-[cs](docs/collector.cs.md) | [Win32_ComputerSystem](https://msdn.microsoft.com/en-us/library/aa394102) metrics (system properties, num cpus/total memory) | ✓
-[dns](docs/collector.dns.md) | [Win32_PerfRawData_DNS_DNS](https://technet.microsoft.com/en-us/library/cc977686.aspx) metrics (DNS Server) |
-[hyperv](docs/collector.hyperv.md) | Performance counters for Hyper-V hosts |
-[iis](docs/collector.iis.md) | [Win32_PerfRawData_W3SVC_WebService](https://msdn.microsoft.com/en-us/library/aa394345) IIS metrics |
-[logical_disk](docs/collector.logical_disk.md) | [Win32_PerfRawData_PerfDisk_LogicalDisk](https://msdn.microsoft.com/en-us/windows/hardware/aa394307(v=vs.71)) metrics (disk I/O) | ✓
-[net](docs/collector.net.md) | [Win32_PerfRawData_Tcpip_NetworkInterface](https://technet.microsoft.com/en-us/security/aa394340(v=vs.80)) metrics (network interface I/O) | ✓
+[ad](docs/collector.ad.md) | Active Directory Domain Services |
+[cpu](docs/collector.cpu.md) | CPU usage | ✓
+[cs](docs/collector.cs.md) | "Computer System" metrics (system properties, num cpus/total memory) | ✓
+[container](docs/collector.container.md) | Container metrics |
+[dns](docs/collector.dns.md) | DNS Server |
+[hyperv](docs/collector.hyperv.md) | Hyper-V hosts |
+[iis](docs/collector.iis.md) | IIS sites and applications |
+[logical_disk](docs/collector.logical_disk.md) | Logical disks, disk I/O | ✓
 [memory](docs/collector.memory.md) | Memory usage metrics |
-[msmq](docs/collector.msmq.md) | [Win32_PerfRawData_MSMQ_MSMQQueue](http://wutils.com/wmi/root/cimv2/win32_perfrawdata_msmq_msmqqueue/) metrics (MSMQ/journal count) |
-[mssql](docs/collector.mssql.md) | various [SQL Server Performance Objects](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/use-sql-server-objects#SQLServerPOs) metrics  |
-[os](docs/collector.os.md) | [Win32_OperatingSystem](https://msdn.microsoft.com/en-us/library/aa394239) metrics (memory, processes, users) | ✓
-[process](docs/collector.process.md) | [Win32_PerfRawData_PerfProc_Process](https://msdn.microsoft.com/en-us/library/aa394323(v=vs.85).aspx) metrics (per-process stats) |
+[msmq](docs/collector.msmq.md) | MSMQ queues |
+[mssql](docs/collector.mssql.md) | [SQL Server Performance Objects](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/use-sql-server-objects#SQLServerPOs) metrics  |
+[netframework_clrexceptions](docs/collector.netframework_clrexceptions.md) | .NET Framework CLR Exceptions |
+[netframework_clrinterop](docs/collector.netframework_clrinterop.md) | .NET Framework Interop Metrics |
+[netframework_clrjit](docs/collector.netframework_clrjit.md) | .NET Framework JIT metrics |
+[netframework_clrloading](docs/collector.netframework_clrloading.md) | .NET Framework CLR Loading metrics |
+[netframework_clrlocksandthreads](docs/collector.netframework_clrlocksandthreads.md) | .NET Framework locks and metrics threads |
+[netframework_clrmemory](docs/collector.netframework_clrmemory.md) |  .NET Framework Memory metrics |
+[netframework_clrremoting](docs/collector.netframework_clrremoting.md) | .NET Framework Remoting metrics |
+[netframework_clrsecurity](docs/collector.netframework_clrsecurity.md) | .NET Framework Security Check metrics |
+[net](docs/collector.net.md) | Network interface I/O | ✓
+[os](docs/collector.os.md) | OS metrics (memory, processes, users) | ✓
+[process](docs/collector.process.md) | Per-process metrics |
 [service](docs/collector.service.md) | Service state metrics | ✓
-[system](docs/collector.system.md) | Win32_PerfRawData_PerfOS_System metrics (system calls) | ✓
-[tcp](docs/collector.tcp.md) | [Win32_PerfRawData_Tcpip_TCPv4](https://msdn.microsoft.com/en-us/library/aa394341(v=vs.85).aspx) metrics (tcp connections) |
+[system](docs/collector.system.md) | System calls | ✓
+[tcp](docs/collector.tcp.md) | TCP connections |
+[thermalzone](docs/collector.thermalzone.md) | Thermal information
 [textfile](docs/collector.textfile.md) | Read prometheus metrics from a text file | ✓
 [vmware](docs/collector.vmware.md) | Performance counters installed by the Vmware Guest agent |
 
@@ -44,13 +54,19 @@ Name | Description
 `LISTEN_PORT` | The port to bind to. Defaults to 9182.
 `METRICS_PATH` | The path at which to serve metrics. Defaults to `/metrics`
 `TEXTFILE_DIR` | As the `--collector.textfile.directory` flag, provide a directory to read text files with metrics from
+`EXTRA_FLAGS` | Allows passing full CLI flags. Defaults to an empty string.
 
-Parameters are sent to the installer via `msiexec`. Example invocation:
+Parameters are sent to the installer via `msiexec`. Example invocations:
 
 ```powershell
 msiexec /i <path-to-msi-file> ENABLED_COLLECTORS=os,iis LISTEN_PORT=5000
 ```
 
+Example service collector with a custom query.
+```powershell
+msiexec /i <path-to-msi-file> ENABLED_COLLECTORS=os,service --% EXTRA_FLAGS="--collector.service.services-where ""Name LIKE 'sql%'"""
+```
+
 ## Roadmap
 
 See [open issues](https://github.com/martinlindhe/wmi_exporter/issues)

appveyor.yml

@@ -1,51 +1,66 @@
-version: "{build}"
-
-os: Windows Server 2012 R2
-
-environment:
-  GOPATH: c:\gopath
-  matrix:
-    - MSI_ARCH: amd64
-      GOARCH: amd64
-    - MSI_ARCH: 386
-      GOARCH: 386
-
-clone_folder: c:\gopath\src\github.com\martinlindhe\wmi_exporter
-
-install:
-  - go version
-  - set PATH=%GOPATH%\bin;c:\go\bin;%GOPATH%\bin\windows_%GOARCH%;%PATH%
-  - go get -u github.com/prometheus/promu
-  - choco install gitversion.portable -y
-
-build_script:
-  - ps: gitversion /output json /showvariable FullSemVer | Set-Content VERSION -PassThru
-  - go test -v ./...
-  - promu build -v
-  - ps: |
-      $ErrorActionPreference = "Stop"
-      if($env:APPVEYOR_REPO_TAG -eq "True") {
-        # The MSI version is not semver compliant, so just take the numerical parts
-        $Version = $env:APPVEYOR_REPO_TAG_NAME -replace '^v?([0-9\.]+).*$','$1'
-        Write-Verbose "Setting msi version to $Version"
-        .\installer\build.ps1 -PathToExecutable .\wmi_exporter.exe -Version $Version -Arch "$env:MSI_ARCH"
-        Push-AppveyorArtifact installer\Output\wmi_exporter-$Version-$env:MSI_ARCH.msi -DeploymentName Installer
-      }
-
-after_build:
-  - 7z a wmi_exporter-%MSI_ARCH%.zip wmi_exporter.exe
-
-artifacts:
-  - name: Executable
-    path: 'wmi_exporter-*.zip'
-
-deploy:
-  - provider: GitHub
-    description: WMI Exporter version $(appveyor_build_version)
-    artifact: Executable,Installer
-    auth_token:
-      secure: 'CrXWeTf7qONUOEki5olFfGEUPMLDeHj61koDXV3OVEaLgtACmnVHsKUub9POflda'
-    draft: false
-    prerelease: false
-    on:
-      appveyor_repo_tag: true
+version: "{build}"
+
+os: Visual Studio 2017
+build: off
+stack: go 1.10
+
+environment:
+  GOPATH: c:\gopath
+
+clone_folder: c:\gopath\src\github.com\martinlindhe\wmi_exporter
+
+install:
+  - set PATH=%GOPATH%\bin;%PATH%
+  - set PATH=%PATH%;C:\mingw-w64\x86_64-7.2.0-posix-seh-rt_v5-rev1\mingw64\bin
+  - go get -u github.com/prometheus/promu
+  - go get -u github.com/alecthomas/gometalinter && gometalinter --install
+  - choco install gitversion.portable make -y
+
+test_script:
+  - make test
+
+after_test:
+  - make lint
+
+build_script:
+  - ps: |
+      $ErrorActionPreference = "Stop"
+      gitversion /output json /showvariable FullSemVer | Set-Content VERSION -PassThru
+      $Version = Get-Content VERSION
+      make crossbuild
+      # GH requires all files to have different names, so add version/arch to differentiate
+      foreach($Arch in "amd64","386") {
+        Rename-Item output\$Arch\wmi_exporter.exe -NewName wmi_exporter-$Version-$Arch.exe
+      }
+
+after_build:
+  - ps: |
+      # Build installer packages only on tagged releases
+      if($env:APPVEYOR_REPO_TAG -ne "True") {
+        return
+      }
+      $ErrorActionPreference = "Stop"
+      $BuildVersion = Get-Content VERSION
+      # The MSI version is not semver compliant, so just take the numerical parts
+      $MSIVersion = $env:APPVEYOR_REPO_TAG_NAME -replace '^v?([0-9\.]+).*$','$1'
+      foreach($Arch in "amd64","386") {
+        Write-Verbose "Building wmi_exporter $MSIVersion msi for $Arch"
+        .\installer\build.ps1 -PathToExecutable .\output\$Arch\wmi_exporter-$BuildVersion-$Arch.exe -Version $MSIVersion -Arch "$Arch"
+        Move-Item installer\Output\wmi_exporter-$MSIVersion-$Arch.msi output\$Arch\
+      }
+  - promu checksum output\
+
+artifacts:
+  - name: Artifacts
+    path: output\**\*
+
+deploy:
+  - provider: GitHub
+    description: WMI Exporter version $(appveyor_build_version)
+    artifact: Artifacts
+    auth_token:
+      secure: 'CrXWeTf7qONUOEki5olFfGEUPMLDeHj61koDXV3OVEaLgtACmnVHsKUub9POflda'
+    draft: false
+    prerelease: false
+    on:
+      appveyor_repo_tag: true

collector/ad.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_DirectoryServices_DirectoryServices
-// Partial docs: https://msdn.microsoft.com/en-us/library/ms803980.aspx
+// +build windows
+
 package collector
 
 import (
@@ -454,7 +454,7 @@ func NewADCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *ADCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *ADCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting ad metrics:", desc, err)
 		return err
@@ -462,6 +462,8 @@ func (c *ADCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_PerfRawData_DirectoryServices_DirectoryServices docs:
+// - https://msdn.microsoft.com/en-us/library/ms803980.aspx
 type Win32_PerfRawData_DirectoryServices_DirectoryServices struct {
 	Name string
 
@@ -485,8 +487,8 @@ type Win32_PerfRawData_DirectoryServices_DirectoryServices struct {
 	DatabasemodifysPersec                                            uint32
 	DatabaserecyclesPersec                                           uint32
 	DigestBindsPersec                                                uint32
-	DRAHighestUSNCommittedHighpart                                   uint32
-	DRAHighestUSNCommittedLowpart                                    uint32
+	DRAHighestUSNCommittedHighpart                                   uint64
+	DRAHighestUSNCommittedLowpart                                    uint64
 	DRAHighestUSNIssuedHighpart                                      uint64
 	DRAHighestUSNIssuedLowpart                                       uint64
 	DRAInboundBytesCompressedBetweenSitesAfterCompressionPersec      uint32

collector/collector.go

@@ -0,0 +1,71 @@
+package collector
+
+import (
+	"strconv"
+
+	"github.com/leoluk/perflib_exporter/perflib"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
+	"golang.org/x/sys/windows/registry"
+)
+
+// ...
+const (
+	// TODO: Make package-local
+	Namespace = "wmi"
+
+	// Conversion factors
+	ticksToSecondsScaleFactor = 1 / 1e7
+	windowsEpoch              = 116444736000000000
+)
+
+// getWindowsVersion reads the version number of the OS from the Registry
+// See https://docs.microsoft.com/en-us/windows/desktop/sysinfo/operating-system-version
+func getWindowsVersion() float64 {
+	k, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Windows NT\CurrentVersion`, registry.QUERY_VALUE)
+	if err != nil {
+		log.Warn("Couldn't open registry", err)
+		return 0
+	}
+	defer func() {
+		err = k.Close()
+		if err != nil {
+			log.Warnf("Failed to close registry key: %v", err)
+		}
+	}()
+
+	currentv, _, err := k.GetStringValue("CurrentVersion")
+	if err != nil {
+		log.Warn("Couldn't open registry to determine current Windows version:", err)
+		return 0
+	}
+
+	currentv_flt, err := strconv.ParseFloat(currentv, 64)
+
+	log.Debugf("Detected Windows version %f\n", currentv_flt)
+
+	return currentv_flt
+}
+
+// Factories ...
+var Factories = make(map[string]func() (Collector, error))
+
+// Collector is the interface a collector has to implement.
+type Collector interface {
+	// Get new metrics and expose them via prometheus registry.
+	Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) (err error)
+}
+
+type ScrapeContext struct {
+	perfObjects map[string]*perflib.PerfObject
+}
+
+// PrepareScrapeContext creates a ScrapeContext to be used during a single scrape
+func PrepareScrapeContext() (*ScrapeContext, error) {
+	objs, err := getPerflibSnapshot()
+	if err != nil {
+		return nil, err
+	}
+
+	return &ScrapeContext{objs}, nil
+}

collector/container.go

@@ -0,0 +1,282 @@
+// +build windows,cgo
+
+package collector
+
+import (
+	"github.com/Microsoft/hcsshim"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
+)
+
+func init() {
+	Factories["container"] = NewContainerMetricsCollector
+}
+
+// A ContainerMetricsCollector is a Prometheus collector for containers metrics
+type ContainerMetricsCollector struct {
+	// Presence
+	ContainerAvailable *prometheus.Desc
+
+	// Number of containers
+	ContainersCount *prometheus.Desc
+	// memory
+	UsageCommitBytes            *prometheus.Desc
+	UsageCommitPeakBytes        *prometheus.Desc
+	UsagePrivateWorkingSetBytes *prometheus.Desc
+
+	// CPU
+	RuntimeTotal  *prometheus.Desc
+	RuntimeUser   *prometheus.Desc
+	RuntimeKernel *prometheus.Desc
+
+	// Network
+	BytesReceived          *prometheus.Desc
+	BytesSent              *prometheus.Desc
+	PacketsReceived        *prometheus.Desc
+	PacketsSent            *prometheus.Desc
+	DroppedPacketsIncoming *prometheus.Desc
+	DroppedPacketsOutgoing *prometheus.Desc
+}
+
+// NewContainerMetricsCollector constructs a new ContainerMetricsCollector
+func NewContainerMetricsCollector() (Collector, error) {
+	const subsystem = "container"
+	return &ContainerMetricsCollector{
+		ContainerAvailable: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "available"),
+			"Available",
+			[]string{"container_id"},
+			nil,
+		),
+		ContainersCount: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "count"),
+			"Number of containers",
+			nil,
+			nil,
+		),
+		UsageCommitBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "memory_usage_commit_bytes"),
+			"Memory Usage Commit Bytes",
+			[]string{"container_id"},
+			nil,
+		),
+		UsageCommitPeakBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "memory_usage_commit_peak_bytes"),
+			"Memory Usage Commit Peak Bytes",
+			[]string{"container_id"},
+			nil,
+		),
+		UsagePrivateWorkingSetBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "memory_usage_private_working_set_bytes"),
+			"Memory Usage Private Working Set Bytes",
+			[]string{"container_id"},
+			nil,
+		),
+		RuntimeTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "cpu_usage_seconds_total"),
+			"Total Run time in Seconds",
+			[]string{"container_id"},
+			nil,
+		),
+		RuntimeUser: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "cpu_usage_seconds_usermode"),
+			"Run Time in User mode in Seconds",
+			[]string{"container_id"},
+			nil,
+		),
+		RuntimeKernel: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "cpu_usage_seconds_kernelmode"),
+			"Run time in Kernel mode in Seconds",
+			[]string{"container_id"},
+			nil,
+		),
+		BytesReceived: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "network_receive_bytes_total"),
+			"Bytes Received on Interface",
+			[]string{"container_id", "interface"},
+			nil,
+		),
+		BytesSent: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "network_transmit_bytes_total"),
+			"Bytes Sent on Interface",
+			[]string{"container_id", "interface"},
+			nil,
+		),
+		PacketsReceived: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "network_receive_packets_total"),
+			"Packets Received on Interface",
+			[]string{"container_id", "interface"},
+			nil,
+		),
+		PacketsSent: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "network_transmit_packets_total"),
+			"Packets Sent on Interface",
+			[]string{"container_id", "interface"},
+			nil,
+		),
+		DroppedPacketsIncoming: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "network_receive_packets_dropped_total"),
+			"Dropped Incoming Packets on Interface",
+			[]string{"container_id", "interface"},
+			nil,
+		),
+		DroppedPacketsOutgoing: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "network_transmit_packets_dropped_total"),
+			"Dropped Outgoing Packets on Interface",
+			[]string{"container_id", "interface"},
+			nil,
+		),
+	}, nil
+}
+
+// Collect sends the metric values for each metric
+// to the provided prometheus Metric channel.
+func (c *ContainerMetricsCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
+	if desc, err := c.collect(ch); err != nil {
+		log.Error("failed collecting ContainerMetricsCollector metrics:", desc, err)
+		return err
+	}
+	return nil
+}
+
+// containerClose closes the container resource
+func containerClose(c hcsshim.Container) {
+	err := c.Close()
+	if err != nil {
+		log.Error(err)
+	}
+}
+
+func (c *ContainerMetricsCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
+
+	// Types Container is passed to get the containers compute systems only
+	containers, err := hcsshim.GetContainers(hcsshim.ComputeSystemQuery{Types: []string{"Container"}})
+	if err != nil {
+		log.Error("Err in Getting containers:", err)
+		return nil, err
+	}
+
+	count := len(containers)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.ContainersCount,
+		prometheus.GaugeValue,
+		float64(count),
+	)
+	if count == 0 {
+		return nil, nil
+	}
+
+	for _, containerDetails := range containers {
+		containerId := containerDetails.ID
+
+		container, err := hcsshim.OpenContainer(containerId)
+		if container != nil {
+			defer containerClose(container)
+		}
+		if err != nil {
+			log.Error("err in opening container: ", containerId, err)
+			continue
+		}
+
+		cstats, err := container.Statistics()
+		if err != nil {
+			log.Error("err in fetching container Statistics: ", containerId, err)
+			continue
+		}
+		// HCS V1 is for docker runtime. Add the docker:// prefix on container_id
+		containerId = "docker://" + containerId
+
+		ch <- prometheus.MustNewConstMetric(
+			c.ContainerAvailable,
+			prometheus.CounterValue,
+			1,
+			containerId,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.UsageCommitBytes,
+			prometheus.GaugeValue,
+			float64(cstats.Memory.UsageCommitBytes),
+			containerId,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.UsageCommitPeakBytes,
+			prometheus.GaugeValue,
+			float64(cstats.Memory.UsageCommitPeakBytes),
+			containerId,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.UsagePrivateWorkingSetBytes,
+			prometheus.GaugeValue,
+			float64(cstats.Memory.UsagePrivateWorkingSetBytes),
+			containerId,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.RuntimeTotal,
+			prometheus.CounterValue,
+			float64(cstats.Processor.TotalRuntime100ns)*ticksToSecondsScaleFactor,
+			containerId,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.RuntimeUser,
+			prometheus.CounterValue,
+			float64(cstats.Processor.RuntimeUser100ns)*ticksToSecondsScaleFactor,
+			containerId,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.RuntimeKernel,
+			prometheus.CounterValue,
+			float64(cstats.Processor.RuntimeKernel100ns)*ticksToSecondsScaleFactor,
+			containerId,
+		)
+
+		if len(cstats.Network) == 0 {
+			log.Info("No Network Stats for container: ", containerId)
+			continue
+		}
+
+		networkStats := cstats.Network
+
+		for _, networkInterface := range networkStats {
+			ch <- prometheus.MustNewConstMetric(
+				c.BytesReceived,
+				prometheus.CounterValue,
+				float64(networkInterface.BytesReceived),
+				containerId, networkInterface.EndpointId,
+			)
+			ch <- prometheus.MustNewConstMetric(
+				c.BytesSent,
+				prometheus.CounterValue,
+				float64(networkInterface.BytesSent),
+				containerId, networkInterface.EndpointId,
+			)
+			ch <- prometheus.MustNewConstMetric(
+				c.PacketsReceived,
+				prometheus.CounterValue,
+				float64(networkInterface.PacketsReceived),
+				containerId, networkInterface.EndpointId,
+			)
+			ch <- prometheus.MustNewConstMetric(
+				c.PacketsSent,
+				prometheus.CounterValue,
+				float64(networkInterface.PacketsSent),
+				containerId, networkInterface.EndpointId,
+			)
+			ch <- prometheus.MustNewConstMetric(
+				c.DroppedPacketsIncoming,
+				prometheus.CounterValue,
+				float64(networkInterface.DroppedPacketsIncoming),
+				containerId, networkInterface.EndpointId,
+			)
+			ch <- prometheus.MustNewConstMetric(
+				c.DroppedPacketsOutgoing,
+				prometheus.CounterValue,
+				float64(networkInterface.DroppedPacketsOutgoing),
+				containerId, networkInterface.EndpointId,
+			)
+			break
+		}
+	}
+
+	return nil, nil
+}

collector/cpu.go

@@ -1,30 +1,77 @@
-// returns data points from Win32_PerfRawData_PerfOS_Processor
-// https://msdn.microsoft.com/en-us/library/aa394317(v=vs.90).aspx - Win32_PerfRawData_PerfOS_Processor class
+// +build windows
+
 package collector
 
 import (
 	"strings"
 
-	"github.com/StackExchange/wmi"
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/common/log"
 )
 
 func init() {
-	Factories["cpu"] = NewCPUCollector
+	Factories["cpu"] = newCPUCollector
 }
 
-// A CPUCollector is a Prometheus collector for WMI Win32_PerfRawData_PerfOS_Processor metrics
-type CPUCollector struct {
+type cpuCollectorBasic struct {
 	CStateSecondsTotal *prometheus.Desc
 	TimeTotal          *prometheus.Desc
 	InterruptsTotal    *prometheus.Desc
 	DPCsTotal          *prometheus.Desc
 }
+type cpuCollectorFull struct {
+	CStateSecondsTotal       *prometheus.Desc
+	TimeTotal                *prometheus.Desc
+	InterruptsTotal          *prometheus.Desc
+	DPCsTotal                *prometheus.Desc
+	ClockInterruptsTotal     *prometheus.Desc
+	IdleBreakEventsTotal     *prometheus.Desc
+	ParkingStatus            *prometheus.Desc
+	ProcessorFrequencyMHz    *prometheus.Desc
+	ProcessorMaxFrequencyMHz *prometheus.Desc
+	ProcessorPerformance     *prometheus.Desc
+}
 
-func NewCPUCollector() (Collector, error) {
+// newCPUCollector constructs a new cpuCollector, appropriate for the running OS
+func newCPUCollector() (Collector, error) {
 	const subsystem = "cpu"
-	return &CPUCollector{
+
+	version := getWindowsVersion()
+	// For Windows 2008 (version 6.0) or earlier we only have the "Processor"
+	// class. As of Windows 2008 R2 (version 6.1) the more detailed
+	// "ProcessorInformation" set is available (although some of the counters
+	// are added in later versions, so we aren't guaranteed to get all of
+	// them).
+	// Value 6.05 was selected to split between Windows versions.
+	if version < 6.05 {
+		return &cpuCollectorBasic{
+			CStateSecondsTotal: prometheus.NewDesc(
+				prometheus.BuildFQName(Namespace, subsystem, "cstate_seconds_total"),
+				"Time spent in low-power idle state",
+				[]string{"core", "state"},
+				nil,
+			),
+			TimeTotal: prometheus.NewDesc(
+				prometheus.BuildFQName(Namespace, subsystem, "time_total"),
+				"Time that processor spent in different modes (idle, user, system, ...)",
+				[]string{"core", "mode"},
+				nil,
+			),
+			InterruptsTotal: prometheus.NewDesc(
+				prometheus.BuildFQName(Namespace, subsystem, "interrupts_total"),
+				"Total number of received and serviced hardware interrupts",
+				[]string{"core"},
+				nil,
+			),
+			DPCsTotal: prometheus.NewDesc(
+				prometheus.BuildFQName(Namespace, subsystem, "dpcs_total"),
+				"Total number of received and serviced deferred procedure calls (DPCs)",
+				[]string{"core"},
+				nil,
+			),
+		}, nil
+	}
+
+	return &cpuCollectorFull{
 		CStateSecondsTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "cstate_seconds_total"),
 			"Time spent in low-power idle state",
@@ -37,7 +84,6 @@ func NewCPUCollector() (Collector, error) {
 			[]string{"core", "mode"},
 			nil,
 		),
-
 		InterruptsTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "interrupts_total"),
 			"Total number of received and serviced hardware interrupts",
@@ -50,162 +96,273 @@ func NewCPUCollector() (Collector, error) {
 			[]string{"core"},
 			nil,
 		),
+		ClockInterruptsTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "clock_interrupts_total"),
+			"Total number of received and serviced clock tick interrupts",
+			[]string{"core"},
+			nil,
+		),
+		IdleBreakEventsTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "idle_break_events_total"),
+			"Total number of time processor was woken from idle",
+			[]string{"core"},
+			nil,
+		),
+		ParkingStatus: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "parking_status"),
+			"Parking Status represents whether a processor is parked or not",
+			[]string{"core"},
+			nil,
+		),
+		ProcessorFrequencyMHz: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "core_frequency_mhz"),
+			"Core frequency in megahertz",
+			[]string{"core"},
+			nil,
+		),
+		ProcessorPerformance: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "processor_performance"),
+			"Processor Performance is the average performance of the processor while it is executing instructions, as a percentage of the nominal performance of the processor. On some processors, Processor Performance may exceed 100%",
+			[]string{"core"},
+			nil,
+		),
 	}, nil
 }
 
-// Collect sends the metric values for each metric
-// to the provided prometheus Metric channel.
-func (c *CPUCollector) Collect(ch chan<- prometheus.Metric) error {
-	if desc, err := c.collect(ch); err != nil {
-		log.Error("failed collecting cpu metrics:", desc, err)
+type perflibProcessor struct {
+	Name                  string
+	C1Transitions         float64 `perflib:"C1 Transitions/sec"`
+	C2Transitions         float64 `perflib:"C2 Transitions/sec"`
+	C3Transitions         float64 `perflib:"C3 Transitions/sec"`
+	DPCRate               float64 `perflib:"DPC Rate"`
+	DPCsQueued            float64 `perflib:"DPCs Queued/sec"`
+	Interrupts            float64 `perflib:"Interrupts/sec"`
+	PercentC2Time         float64 `perflib:"% C1 Time"`
+	PercentC3Time         float64 `perflib:"% C2 Time"`
+	PercentC1Time         float64 `perflib:"% C3 Time"`
+	PercentDPCTime        float64 `perflib:"% DPC Time"`
+	PercentIdleTime       float64 `perflib:"% Idle Time"`
+	PercentInterruptTime  float64 `perflib:"% Interrupt Time"`
+	PercentPrivilegedTime float64 `perflib:"% Privileged Time"`
+	PercentProcessorTime  float64 `perflib:"% Processor Time"`
+	PercentUserTime       float64 `perflib:"% User Time"`
+}
+
+func (c *cpuCollectorBasic) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
+	data := make([]perflibProcessor, 0)
+	err := unmarshalObject(ctx.perfObjects["Processor"], &data)
+	if err != nil {
 		return err
 	}
-	return nil
-}
 
-type Win32_PerfRawData_PerfOS_Processor struct {
-	Name                  string
-	C1TransitionsPersec   uint64
-	C2TransitionsPersec   uint64
-	C3TransitionsPersec   uint64
-	DPCRate               uint32
-	DPCsQueuedPersec      uint32
-	InterruptsPersec      uint32
-	PercentC1Time         uint64
-	PercentC2Time         uint64
-	PercentC3Time         uint64
-	PercentDPCTime        uint64
-	PercentIdleTime       uint64
-	PercentInterruptTime  uint64
-	PercentPrivilegedTime uint64
-	PercentProcessorTime  uint64
-	PercentUserTime       uint64
-}
-
-/* NOTE: This is an alternative class, but it is not as widely available. Decide which to use
-type Win32_PerfRawData_Counters_ProcessorInformation struct {
-	Name                        string
-	AverageIdleTime             uint64
-	C1TransitionsPersec         uint64
-	C2TransitionsPersec         uint64
-	C3TransitionsPersec         uint64
-	ClockInterruptsPersec       uint64
-	DPCRate                     uint64
-	DPCsQueuedPersec            uint64
-	IdleBreakEventsPersec       uint64
-	InterruptsPersec            uint64
-	ParkingStatus               uint64
-	PercentC1Time               uint64
-	PercentC2Time               uint64
-	PercentC3Time               uint64
-	PercentDPCTime              uint64
-	PercentIdleTime             uint64
-	PercentInterruptTime        uint64
-	PercentofMaximumFrequency   uint64
-	PercentPerformanceLimit     uint64
-	PercentPriorityTime         uint64
-	PercentPrivilegedTime       uint64
-	PercentPrivilegedUtility    uint64
-	PercentProcessorPerformance uint64
-	PercentProcessorTime        uint64
-	PercentProcessorUtility     uint64
-	PercentUserTime             uint64
-	PerformanceLimitFlags       uint64
-	ProcessorFrequency          uint64
-	ProcessorStateFlags         uint64
-}*/
-
-func (c *CPUCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
-	var dst []Win32_PerfRawData_PerfOS_Processor
-	q := queryAll(&dst)
-	if err := wmi.Query(q, &dst); err != nil {
-		return nil, err
-	}
-
-	for _, data := range dst {
-		if strings.Contains(data.Name, "_Total") {
+	for _, cpu := range data {
+		if strings.Contains(strings.ToLower(cpu.Name), "_total") {
 			continue
 		}
-
-		core := data.Name
-
-		// These are only available from Win32_PerfRawData_Counters_ProcessorInformation, which is only available from Win2008R2+
-		/*ch <- prometheus.MustNewConstMetric(
-			c.ProcessorFrequency,
-			prometheus.GaugeValue,
-			float64(data.ProcessorFrequency),
-			socket, core,
-		)
-		ch <- prometheus.MustNewConstMetric(
-			c.MaximumFrequency,
-			prometheus.GaugeValue,
-			float64(data.PercentofMaximumFrequency)/100*float64(data.ProcessorFrequency),
-			socket, core,
-		)*/
+		core := cpu.Name
 
 		ch <- prometheus.MustNewConstMetric(
 			c.CStateSecondsTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentC1Time)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentC1Time,
 			core, "c1",
 		)
 		ch <- prometheus.MustNewConstMetric(
 			c.CStateSecondsTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentC2Time)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentC2Time,
 			core, "c2",
 		)
 		ch <- prometheus.MustNewConstMetric(
 			c.CStateSecondsTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentC3Time)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentC3Time,
 			core, "c3",
 		)
 
 		ch <- prometheus.MustNewConstMetric(
 			c.TimeTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentIdleTime)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentIdleTime,
 			core, "idle",
 		)
 		ch <- prometheus.MustNewConstMetric(
 			c.TimeTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentInterruptTime)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentInterruptTime,
 			core, "interrupt",
 		)
 		ch <- prometheus.MustNewConstMetric(
 			c.TimeTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentDPCTime)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentDPCTime,
 			core, "dpc",
 		)
 		ch <- prometheus.MustNewConstMetric(
 			c.TimeTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentPrivilegedTime)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentPrivilegedTime,
 			core, "privileged",
 		)
 		ch <- prometheus.MustNewConstMetric(
 			c.TimeTotal,
-			prometheus.GaugeValue,
-			float64(data.PercentUserTime)*ticksToSecondsScaleFactor,
+			prometheus.CounterValue,
+			cpu.PercentUserTime,
 			core, "user",
 		)
 
 		ch <- prometheus.MustNewConstMetric(
 			c.InterruptsTotal,
 			prometheus.CounterValue,
-			float64(data.InterruptsPersec),
+			cpu.Interrupts,
 			core,
 		)
 		ch <- prometheus.MustNewConstMetric(
 			c.DPCsTotal,
 			prometheus.CounterValue,
-			float64(data.DPCsQueuedPersec),
+			cpu.DPCsQueued,
 			core,
 		)
 	}
 
-	return nil, nil
+	return nil
+}
+
+type perflibProcessorInformation struct {
+	Name                     string
+	C1TimeSeconds            float64 `perflib:"% C1 Time"`
+	C2TimeSeconds            float64 `perflib:"% C2 Time"`
+	C3TimeSeconds            float64 `perflib:"% C3 Time"`
+	C1TransitionsTotal       float64 `perflib:"C1 Transitions/sec"`
+	C2TransitionsTotal       float64 `perflib:"C2 Transitions/sec"`
+	C3TransitionsTotal       float64 `perflib:"C3 Transitions/sec"`
+	ClockInterruptsTotal     float64 `perflib:"Clock Interrupts/sec"`
+	DPCsQueuedTotal          float64 `perflib:"DPCs Queued/sec"`
+	DPCTimeSeconds           float64 `perflib:"% DPC Time"`
+	IdleBreakEventsTotal     float64 `perflib:"Idle Break Events/sec"`
+	IdleTimeSeconds          float64 `perflib:"% Idle Time"`
+	InterruptsTotal          float64 `perflib:"Interrupts/sec"`
+	InterruptTimeSeconds     float64 `perflib:"% Interrupt Time"`
+	ParkingStatus            float64 `perflib:"Parking Status"`
+	PerformanceLimitPercent  float64 `perflib:"% Performance Limit"`
+	PriorityTimeSeconds      float64 `perflib:"% Priority Time"`
+	PrivilegedTimeSeconds    float64 `perflib:"% Privileged Time"`
+	PrivilegedUtilitySeconds float64 `perflib:"% Privileged Utility"`
+	ProcessorFrequencyMHz    float64 `perflib:"Processor Frequency"`
+	ProcessorPerformance     float64 `perflib:"% Processor Performance"`
+	ProcessorTimeSeconds     float64 `perflib:"% Processor Time"`
+	ProcessorUtilityRate     float64 `perflib:"% Processor Utility"`
+	UserTimeSeconds          float64 `perflib:"% User Time"`
+}
+
+func (c *cpuCollectorFull) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
+	data := make([]perflibProcessorInformation, 0)
+	err := unmarshalObject(ctx.perfObjects["Processor Information"], &data)
+	if err != nil {
+		return err
+	}
+
+	for _, cpu := range data {
+		if strings.Contains(strings.ToLower(cpu.Name), "_total") {
+			continue
+		}
+		core := cpu.Name
+
+		ch <- prometheus.MustNewConstMetric(
+			c.CStateSecondsTotal,
+			prometheus.CounterValue,
+			cpu.C1TimeSeconds,
+			core, "c1",
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.CStateSecondsTotal,
+			prometheus.CounterValue,
+			cpu.C2TimeSeconds,
+			core, "c2",
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.CStateSecondsTotal,
+			prometheus.CounterValue,
+			cpu.C3TimeSeconds,
+			core, "c3",
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.TimeTotal,
+			prometheus.CounterValue,
+			cpu.IdleTimeSeconds,
+			core, "idle",
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.TimeTotal,
+			prometheus.CounterValue,
+			cpu.InterruptTimeSeconds,
+			core, "interrupt",
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.TimeTotal,
+			prometheus.CounterValue,
+			cpu.DPCTimeSeconds,
+			core, "dpc",
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.TimeTotal,
+			prometheus.CounterValue,
+			cpu.PrivilegedTimeSeconds,
+			core, "privileged",
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.TimeTotal,
+			prometheus.CounterValue,
+			cpu.UserTimeSeconds,
+			core, "user",
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.InterruptsTotal,
+			prometheus.CounterValue,
+			cpu.InterruptsTotal,
+			core,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.DPCsTotal,
+			prometheus.CounterValue,
+			cpu.DPCsQueuedTotal,
+			core,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.ClockInterruptsTotal,
+			prometheus.CounterValue,
+			cpu.ClockInterruptsTotal,
+			core,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.IdleBreakEventsTotal,
+			prometheus.CounterValue,
+			cpu.IdleBreakEventsTotal,
+			core,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.ParkingStatus,
+			prometheus.GaugeValue,
+			cpu.ParkingStatus,
+			core,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.ProcessorFrequencyMHz,
+			prometheus.GaugeValue,
+			cpu.ProcessorFrequencyMHz,
+			core,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.ProcessorPerformance,
+			prometheus.GaugeValue,
+			cpu.ProcessorPerformance,
+			core,
+		)
+	}
+
+	return nil
 }

collector/cs.go

@@ -1,5 +1,4 @@
-// returns data points from Win32_ComputerSystem
-// https://msdn.microsoft.com/en-us/library/aa394102 - Win32_ComputerSystem class
+// +build windows
 
 package collector
 
@@ -43,7 +42,7 @@ func NewCSCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *CSCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *CSCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting cs metrics:", desc, err)
 		return err
@@ -51,6 +50,8 @@ func (c *CSCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_ComputerSystem docs:
+// - https://msdn.microsoft.com/en-us/library/aa394102
 type Win32_ComputerSystem struct {
 	NumberOfLogicalProcessors uint32
 	TotalPhysicalMemory       uint64

collector/dns.go

@@ -1,6 +1,5 @@
-// returns data points from Win32_PerfRawData_DNS_DNS
-// https://msdn.microsoft.com/en-us/library/ms803992.aspx?f=255&MSPPError=-2147217396
-// https://technet.microsoft.com/en-us/library/cc977686.aspx
+// +build windows
+
 package collector
 
 import (
@@ -182,7 +181,7 @@ func NewDNSCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *DNSCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *DNSCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting dns metrics:", desc, err)
 		return err
@@ -190,6 +189,9 @@ func (c *DNSCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_PerfRawData_DNS_DNS docs:
+// - https://msdn.microsoft.com/en-us/library/ms803992.aspx?f=255&MSPPError=-2147217396
+// - https://technet.microsoft.com/en-us/library/cc977686.aspx
 type Win32_PerfRawData_DNS_DNS struct {
 	AXFRRequestReceived            uint32
 	AXFRRequestSent                uint32

collector/hyperv.go

@@ -1,3 +1,5 @@
+// +build windows
+
 package collector
 
 import (
@@ -595,7 +597,7 @@ func NewHyperVCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *HyperVCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *HyperVCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collectVmHealth(ch); err != nil {
 		log.Error("failed collecting hyperV health status metrics:", desc, err)
 		return err

collector/iis.go

@@ -1,8 +1,4 @@
-// returns data points from the following classes:
-// - Win32_PerfRawData_W3SVC_WebService
-// - Win32_PerfRawData_APPPOOLCountersProvider_APPPOOLWAS
-// - Win32_PerfRawData_W3SVCW3WPCounterProvider_W3SVCW3WP
-// - Win32_PerfRawData_W3SVC_WebServiceCache
+// +build windows
 
 package collector
 
@@ -34,7 +30,12 @@ func getIISVersion() simple_version {
 		log.Warn("Couldn't open registry to determine IIS version:", err)
 		return simple_version{}
 	}
-	defer k.Close()
+	defer func() {
+		err = k.Close()
+		if err != nil {
+			log.Warnf("Failed to close registry key: %v", err)
+		}
+	}()
 
 	major, _, err := k.GetIntegerValue("MajorVersion")
 	if err != nil {
@@ -806,8 +807,8 @@ func NewIISCollector() (Collector, error) {
 			nil,
 		),
 
-		appWhitelistPattern: regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *siteWhitelist)),
-		appBlacklistPattern: regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *siteBlacklist)),
+		appWhitelistPattern: regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *appWhitelist)),
+		appBlacklistPattern: regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *appBlacklist)),
 	}
 
 	buildIIS.iis_version = getIISVersion()
@@ -817,7 +818,7 @@ func NewIISCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *IISCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *IISCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting iis metrics:", desc, err)
 		return err
@@ -984,7 +985,7 @@ type Win32_PerfRawData_W3SVC_WebServiceCache struct {
 	URICacheMisses                 uint32
 }
 
-var ApplicationStates = map[uint32]string{
+var applicationStates = map[uint32]string{
 	1: "Uninitialized",
 	2: "Initialized",
 	3: "Running",
@@ -1265,7 +1266,7 @@ func (c *IISCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, e
 		}
 
 		// Guages
-		for key, label := range ApplicationStates {
+		for key, label := range applicationStates {
 			isCurrentState := 0.0
 			if key == app.CurrentApplicationPoolState {
 				isCurrentState = 1.0

collector/logical_disk.go

@@ -1,6 +1,4 @@
-// returns data points from Win32_PerfRawData_PerfDisk_LogicalDisk
-// https://msdn.microsoft.com/en-us/windows/hardware/aa394307(v=vs.71) - Win32_PerfRawData_PerfDisk_LogicalDisk class
-// https://msdn.microsoft.com/en-us/library/ms803973.aspx - LogicalDisk object reference
+// +build windows
 
 package collector
 
@@ -136,7 +134,7 @@ func NewLogicalDiskCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *LogicalDiskCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *LogicalDiskCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting logical_disk metrics:", desc, err)
 		return err
@@ -144,6 +142,9 @@ func (c *LogicalDiskCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_PerfRawData_PerfDisk_LogicalDisk docs:
+// - https://msdn.microsoft.com/en-us/windows/hardware/aa394307(v=vs.71) - Win32_PerfRawData_PerfDisk_LogicalDisk class
+// - https://msdn.microsoft.com/en-us/library/ms803973.aspx - LogicalDisk object reference
 type Win32_PerfRawData_PerfDisk_LogicalDisk struct {
 	Name                   string
 	CurrentDiskQueueLength uint32

collector/memory.go

@@ -1,5 +1,8 @@
 // returns data points from Win32_PerfRawData_PerfOS_Memory
 // <add link to documentation here> - Win32_PerfRawData_PerfOS_Memory class
+
+// +build windows
+
 package collector
 
 import (
@@ -253,7 +256,7 @@ func NewMemoryCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *MemoryCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *MemoryCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting memory metrics:", desc, err)
 		return err

collector/msmq.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_MSMQ_MSMQQueue
-// <add link to documentation here> - Win32_PerfRawData_MSMQ_MSMQQueue class
+// +build windows
+
 package collector
 
 import (
@@ -33,7 +33,7 @@ type Win32_PerfRawData_MSMQ_MSMQQueueCollector struct {
 func NewMSMQCollector() (Collector, error) {
 	const subsystem = "msmq"
 
-	if *msmqWhereClause != "" {
+	if *msmqWhereClause == "" {
 		log.Warn("No where-clause specified for msmq collector. This will generate a very large number of metrics!")
 	}
 
@@ -68,7 +68,7 @@ func NewMSMQCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *Win32_PerfRawData_MSMQ_MSMQQueueCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *Win32_PerfRawData_MSMQ_MSMQQueueCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting msmq metrics:", desc, err)
 		return err

collector/mssql.go

@@ -1,22 +1,4 @@
-// returns data points from the following classes:
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerAccessMethods
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-access-methods-object
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerAvailabilityReplica
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-availability-replica
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerBufferManager
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-buffer-manager-object
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerDatabaseReplica
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-database-replica
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerDatabases
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-databases-object?view=sql-server-2017
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerGeneralStatistics
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-general-statistics-object
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerLocks
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-locks-object
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerMemoryManager
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-memory-manager-object
-// - Win32_PerfRawData_MSSQLSERVER_SQLServerSQLStatistics
-//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-sql-statistics-object
+// +build windows
 
 package collector
 
@@ -62,7 +44,12 @@ func getMSSQLInstances() mssqlInstancesType {
 		log.Warn("Couldn't open registry to determine SQL instances:", err)
 		return sqlDefaultInstance
 	}
-	defer k.Close()
+	defer func() {
+		err = k.Close()
+		if err != nil {
+			log.Warnf("Failed to close registry key: %v", err)
+		}
+	}()
 
 	instanceNames, err := k.ReadValueNames(0)
 	if err != nil {
@@ -104,7 +91,7 @@ func mssqlBuildWMIInstanceClass(suffix string, instance string) string {
 type mssqlCollectorsMap map[string]mssqlCollectorFunc
 
 func mssqlAvailableClassCollectors() string {
-	return "accessmethods,availreplica,bufman,databases,dbreplica,genstats,locks,memmgr,sqlstats"
+	return "accessmethods,availreplica,bufman,databases,dbreplica,genstats,locks,memmgr,sqlstats,sqlerrors,transactions"
 }
 
 func (c *MSSQLCollector) getMSSQLCollectors() mssqlCollectorsMap {
@@ -118,6 +105,8 @@ func (c *MSSQLCollector) getMSSQLCollectors() mssqlCollectorsMap {
 	mssqlCollectors["locks"] = c.collectLocks
 	mssqlCollectors["memmgr"] = c.collectMemoryManager
 	mssqlCollectors["sqlstats"] = c.collectSQLStats
+	mssqlCollectors["sqlerrors"] = c.collectSQLErrors
+	mssqlCollectors["transactions"] = c.collectTransactions
 
 	return mssqlCollectors
 }
@@ -371,6 +360,24 @@ type MSSQLCollector struct {
 	SQLStatsSQLReCompilations       *prometheus.Desc
 	SQLStatsUnsafeAutoParams        *prometheus.Desc
 
+	// Win32_PerfRawData_{instance}_SQLServerSQLErrors
+	SQLErrorsTotal *prometheus.Desc
+
+	// Win32_PerfRawData_{instance}_SQLServerTransactions
+	TransactionsTempDbFreeSpaceBytes             *prometheus.Desc
+	TransactionsLongestTransactionRunningSeconds *prometheus.Desc
+	TransactionsNonSnapshotVersionActiveTotal    *prometheus.Desc
+	TransactionsSnapshotActiveTotal              *prometheus.Desc
+	TransactionsActiveTotal                      *prometheus.Desc
+	TransactionsUpdateConflictsTotal             *prometheus.Desc
+	TransactionsUpdateSnapshotActiveTotal        *prometheus.Desc
+	TransactionsVersionCleanupRateBytes          *prometheus.Desc
+	TransactionsVersionGenerationRateBytes       *prometheus.Desc
+	TransactionsVersionStoreSizeBytes            *prometheus.Desc
+	TransactionsVersionStoreUnits                *prometheus.Desc
+	TransactionsVersionStoreCreationUnits        *prometheus.Desc
+	TransactionsVersionStoreTruncationUnits      *prometheus.Desc
+
 	mssqlInstances             mssqlInstancesType
 	mssqlCollectors            mssqlCollectorsMap
 	mssqlChildCollectorFailure int
@@ -381,7 +388,7 @@ func NewMSSQLCollector() (Collector, error) {
 
 	const subsystem = "mssql"
 
-	MSSQLCollector := MSSQLCollector{
+	mssqlCollector := MSSQLCollector{
 		// meta
 		mssqlScrapeDurationDesc: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "collector_duration_seconds"),
@@ -1650,20 +1657,108 @@ func NewMSSQLCollector() (Collector, error) {
 			nil,
 		),
 
+		// Win32_PerfRawData_{instance}_SQLServerSQLErrors
+		SQLErrorsTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "sql_errors_total"),
+			"(SQLErrors.Total)",
+			[]string{"instance", "resource"},
+			nil,
+		),
+
+		// Win32_PerfRawData_{instance}_SQLServerTransactions
+		TransactionsTempDbFreeSpaceBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_tempdb_free_space_bytes"),
+			"(Transactions.FreeSpaceInTempDbKB)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsLongestTransactionRunningSeconds: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_longest_transaction_running_seconds"),
+			"(Transactions.LongestTransactionRunningTime)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsNonSnapshotVersionActiveTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_nonsnapshot_version_active_total"),
+			"(Transactions.NonSnapshotVersionTransactions)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsSnapshotActiveTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_snapshot_active_total"),
+			"(Transactions.SnapshotTransactions)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsActiveTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_active_total"),
+			"(Transactions.Transactions)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsUpdateConflictsTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_update_conflicts_total"),
+			"(Transactions.UpdateConflictRatio)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsUpdateSnapshotActiveTotal: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_update_snapshot_active_total"),
+			"(Transactions.UpdateSnapshotTransactions)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsVersionCleanupRateBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_version_cleanup_rate_bytes"),
+			"(Transactions.VersionCleanupRateKBs)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsVersionGenerationRateBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_version_generation_rate_bytes"),
+			"(Transactions.VersionGenerationRateKBs)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsVersionStoreSizeBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_version_store_size_bytes"),
+			"(Transactions.VersionStoreSizeKB)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsVersionStoreUnits: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_version_store_units"),
+			"(Transactions.VersionStoreUnitCount)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsVersionStoreCreationUnits: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_version_store_creation_units"),
+			"(Transactions.VersionStoreUnitCreation)",
+			[]string{"instance"},
+			nil,
+		),
+		TransactionsVersionStoreTruncationUnits: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "transactions_version_store_truncation_units"),
+			"(Transactions.VersionStoreUnitTruncation)",
+			[]string{"instance"},
+			nil,
+		),
+
 		mssqlInstances: getMSSQLInstances(),
 	}
 
-	MSSQLCollector.mssqlCollectors = MSSQLCollector.getMSSQLCollectors()
+	mssqlCollector.mssqlCollectors = mssqlCollector.getMSSQLCollectors()
 
 	if *mssqlPrintCollectors {
 		fmt.Printf("Available SQLServer Classes:\n")
-		for name := range MSSQLCollector.mssqlCollectors {
+		for name := range mssqlCollector.mssqlCollectors {
 			fmt.Printf(" - %s\n", name)
 		}
 		os.Exit(0)
 	}
 
-	return &MSSQLCollector, nil
+	return &mssqlCollector, nil
 }
 
 type mssqlCollectorFunc func(ch chan<- prometheus.Metric, sqlInstance string) (*prometheus.Desc, error)
@@ -1700,7 +1795,7 @@ func (c *MSSQLCollector) execute(name string, fn mssqlCollectorFunc, ch chan<- p
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *MSSQLCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *MSSQLCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	wg := sync.WaitGroup{}
 
 	enabled := mssqlExpandEnabledCollectors(*mssqlEnabledCollectors)
@@ -1721,6 +1816,9 @@ func (c *MSSQLCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// win32PerfRawDataSQLServerAccessMethods docs:
+// - Win32_PerfRawData_MSSQLSERVER_SQLServerAccessMethods
+//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-access-methods-object
 type win32PerfRawDataSQLServerAccessMethods struct {
 	AUcleanupbatchesPersec        uint64
 	AUcleanupsPersec              uint64
@@ -2085,6 +2183,8 @@ func (c *MSSQLCollector) collectAccessMethods(ch chan<- prometheus.Metric, sqlIn
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerAvailabilityReplica docs:
+//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-availability-replica
 type win32PerfRawDataSQLServerAvailabilityReplica struct {
 	Name                           string
 	BytesReceivedfromReplicaPersec uint64
@@ -2177,6 +2277,8 @@ func (c *MSSQLCollector) collectAvailabilityReplica(ch chan<- prometheus.Metric,
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerBufferManager docs:
+//   https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-buffer-manager-object
 type win32PerfRawDataSQLServerBufferManager struct {
 	BackgroundwriterpagesPersec   uint64
 	Buffercachehitratio           uint64
@@ -2374,6 +2476,8 @@ func (c *MSSQLCollector) collectBufferManager(ch chan<- prometheus.Metric, sqlIn
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerDatabaseReplica docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-database-replica
 type win32PerfRawDataSQLServerDatabaseReplica struct {
 	Name                            string
 	DatabaseFlowControlDelay        uint64
@@ -2579,13 +2683,15 @@ func (c *MSSQLCollector) collectDatabaseReplica(ch chan<- prometheus.Metric, sql
 		ch <- prometheus.MustNewConstMetric(
 			c.DBReplicaTransactionDelay,
 			prometheus.GaugeValue,
-			float64(v.TransactionDelay)*1000.0,
+			float64(v.TransactionDelay)/1000.0,
 			sqlInstance, replicaName,
 		)
 	}
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerDatabases docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-databases-object?view=sql-server-2017
 type win32PerfRawDataSQLServerDatabases struct {
 	Name                             string
 	ActiveTransactions               uint64
@@ -2974,6 +3080,8 @@ func (c *MSSQLCollector) collectDatabases(ch chan<- prometheus.Metric, sqlInstan
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerGeneralStatistics docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-general-statistics-object
 type win32PerfRawDataSQLServerGeneralStatistics struct {
 	ActiveTempTables              uint64
 	ConnectionResetPersec         uint64
@@ -3186,6 +3294,8 @@ func (c *MSSQLCollector) collectGeneralStatistics(ch chan<- prometheus.Metric, s
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerLocks docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-locks-object
 type win32PerfRawDataSQLServerLocks struct {
 	Name                       string
 	AverageWaitTimems          uint64
@@ -3262,6 +3372,8 @@ func (c *MSSQLCollector) collectLocks(ch chan<- prometheus.Metric, sqlInstance s
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerMemoryManager docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-memory-manager-object
 type win32PerfRawDataSQLServerMemoryManager struct {
 	ConnectionMemoryKB       uint64
 	DatabaseCacheMemoryKB    uint64
@@ -3443,6 +3555,8 @@ func (c *MSSQLCollector) collectMemoryManager(ch chan<- prometheus.Metric, sqlIn
 	return nil, nil
 }
 
+// Win32_PerfRawData_MSSQLSERVER_SQLServerSQLStatistics docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-sql-statistics-object
 type win32PerfRawDataSQLServerSQLStatistics struct {
 	AutoParamAttemptsPersec       uint64
 	BatchRequestsPersec           uint64
@@ -3552,3 +3666,162 @@ func (c *MSSQLCollector) collectSQLStats(ch chan<- prometheus.Metric, sqlInstanc
 
 	return nil, nil
 }
+
+type win32PerfRawDataSQLServerSQLErrors struct {
+	Name         string
+	ErrorsPersec uint64
+}
+
+// Win32_PerfRawData_MSSQLSERVER_SQLServerErrors docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-sql-errors-object
+func (c *MSSQLCollector) collectSQLErrors(ch chan<- prometheus.Metric, sqlInstance string) (*prometheus.Desc, error) {
+	var dst []win32PerfRawDataSQLServerSQLErrors
+	log.Debugf("mssql_sqlerrors collector iterating sql instance %s.", sqlInstance)
+
+	class := mssqlBuildWMIInstanceClass("SQLErrors", sqlInstance)
+	q := queryAllForClassWhere(&dst, class, `Name <> '_Total'`)
+	if err := wmi.Query(q, &dst); err != nil {
+		return nil, err
+	}
+
+	for _, v := range dst {
+		resource := v.Name
+
+		ch <- prometheus.MustNewConstMetric(
+			c.SQLErrorsTotal,
+			prometheus.CounterValue,
+			float64(v.ErrorsPersec),
+			sqlInstance, resource,
+		)
+	}
+
+	return nil, nil
+}
+
+type win32PerfRawDataSqlServerTransactions struct {
+	FreeSpaceintempdbKB            uint64
+	LongestTransactionRunningTime  uint64
+	NonSnapshotVersionTransactions uint64
+	SnapshotTransactions           uint64
+	Transactions                   uint64
+	Updateconflictratio            uint64
+	UpdateSnapshotTransactions     uint64
+	VersionCleanuprateKBPers       uint64
+	VersionGenerationrateKBPers    uint64
+	VersionStoreSizeKB             uint64
+	VersionStoreunitcount          uint64
+	VersionStoreunitcreation       uint64
+	VersionStoreunittruncation     uint64
+}
+
+// Win32_PerfRawData_MSSQLSERVER_Transactions docs:
+// - https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-transactions-object
+func (c *MSSQLCollector) collectTransactions(ch chan<- prometheus.Metric, sqlInstance string) (*prometheus.Desc, error) {
+	var dst []win32PerfRawDataSqlServerTransactions
+	log.Debugf("mssql_transactions collector iterating sql instance %s.", sqlInstance)
+
+	class := mssqlBuildWMIInstanceClass("Transactions", sqlInstance)
+	q := queryAllForClass(&dst, class)
+	if err := wmi.Query(q, &dst); err != nil {
+		return nil, err
+	}
+
+	if len(dst) == 0 {
+		return nil, errors.New("WMI query returned empty result set")
+	}
+
+	v := dst[0]
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsTempDbFreeSpaceBytes,
+		prometheus.GaugeValue,
+		float64(v.FreeSpaceintempdbKB*1024),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsLongestTransactionRunningSeconds,
+		prometheus.GaugeValue,
+		float64(v.LongestTransactionRunningTime),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsNonSnapshotVersionActiveTotal,
+		prometheus.CounterValue,
+		float64(v.NonSnapshotVersionTransactions),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsSnapshotActiveTotal,
+		prometheus.CounterValue,
+		float64(v.SnapshotTransactions),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsActiveTotal,
+		prometheus.CounterValue,
+		float64(v.Transactions),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsUpdateConflictsTotal,
+		prometheus.CounterValue,
+		float64(v.Updateconflictratio),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsUpdateSnapshotActiveTotal,
+		prometheus.CounterValue,
+		float64(v.UpdateSnapshotTransactions),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsVersionCleanupRateBytes,
+		prometheus.GaugeValue,
+		float64(v.VersionCleanuprateKBPers*1024),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsVersionGenerationRateBytes,
+		prometheus.GaugeValue,
+		float64(v.VersionGenerationrateKBPers*1024),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsVersionStoreSizeBytes,
+		prometheus.GaugeValue,
+		float64(v.VersionStoreSizeKB*1024),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsVersionStoreUnits,
+		prometheus.CounterValue,
+		float64(v.VersionStoreunitcount),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsVersionStoreCreationUnits,
+		prometheus.CounterValue,
+		float64(v.VersionStoreunitcreation),
+		sqlInstance,
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.TransactionsVersionStoreTruncationUnits,
+		prometheus.CounterValue,
+		float64(v.VersionStoreunittruncation),
+		sqlInstance,
+	)
+
+	return nil, nil
+}

collector/net.go

@@ -1,8 +1,4 @@
-// returns data points from Win32_PerfRawData_Tcpip_NetworkInterface
-
-// https://technet.microsoft.com/en-us/security/aa394340(v=vs.80) (Win32_PerfRawData_Tcpip_NetworkInterface class)
-// https://msdn.microsoft.com/en-us/library/aa394216 (Win32_NetworkAdapter class)
-// https://msdn.microsoft.com/en-us/library/aa394353 (Win32_PnPEntity class)
+// +build windows
 
 package collector
 
@@ -136,7 +132,7 @@ func NewNetworkCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NetworkCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NetworkCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting net metrics:", desc, err)
 		return err
@@ -150,6 +146,8 @@ func mangleNetworkName(name string) string {
 	return nicNameToUnderscore.ReplaceAllString(name, "_")
 }
 
+// Win32_PerfRawData_Tcpip_NetworkInterface docs:
+// - https://technet.microsoft.com/en-us/security/aa394340(v=vs.80)
 type Win32_PerfRawData_Tcpip_NetworkInterface struct {
 	BytesReceivedPerSec      uint64
 	BytesSentPerSec          uint64

collector/net_test.go

@@ -1,3 +1,5 @@
+// +build windows
+
 package collector
 
 import "testing"

collector/netframework_clrexceptions.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRExceptions
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRExceptions class
+// +build windows
+
 package collector
 
 import (
@@ -53,7 +53,7 @@ func NewNETFramework_NETCLRExceptionsCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRExceptionsCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRExceptionsCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrexceptions metrics:", desc, err)
 		return err

collector/netframework_clrinterop.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRInterop
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRInterop class
+// +build windows
+
 package collector
 
 import (
@@ -46,7 +46,7 @@ func NewNETFramework_NETCLRInteropCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRInteropCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRInteropCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrinterop metrics:", desc, err)
 		return err

collector/netframework_clrjit.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRJit
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRJit class
+// +build windows
+
 package collector
 
 import (
@@ -53,7 +53,7 @@ func NewNETFramework_NETCLRJitCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRJitCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRJitCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrjit metrics:", desc, err)
 		return err

collector/netframework_clrloading.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRLoading
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRLoading class
+// +build windows
+
 package collector
 
 import (
@@ -88,7 +88,7 @@ func NewNETFramework_NETCLRLoadingCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRLoadingCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRLoadingCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrloading metrics:", desc, err)
 		return err

collector/netframework_clrlocksandthreads.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRLocksAndThreads
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRLocksAndThreads class
+// +build windows
+
 package collector
 
 import (
@@ -74,7 +74,7 @@ func NewNETFramework_NETCLRLocksAndThreadsCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRLocksAndThreadsCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRLocksAndThreadsCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrlocksandthreads metrics:", desc, err)
 		return err

collector/netframework_clrmemory.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRMemory
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRMemory class
+// +build windows
+
 package collector
 
 import (
@@ -112,7 +112,7 @@ func NewNETFramework_NETCLRMemoryCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRMemoryCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRMemoryCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrmemory metrics:", desc, err)
 		return err

collector/netframework_clrremoting.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRRemoting
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRRemoting class
+// +build windows
+
 package collector
 
 import (
@@ -67,7 +67,7 @@ func NewNETFramework_NETCLRRemotingCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRRemotingCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRRemotingCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrremoting metrics:", desc, err)
 		return err

collector/netframework_clrsecurity.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_NETFramework_NETCLRSecurity
-// <add link to documentation here> - Win32_PerfRawData_NETFramework_NETCLRSecurity class
+// +build windows
+
 package collector
 
 import (
@@ -53,7 +53,7 @@ func NewNETFramework_NETCLRSecurityCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *NETFramework_NETCLRSecurityCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *NETFramework_NETCLRSecurityCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting win32_perfrawdata_netframework_netclrsecurity metrics:", desc, err)
 		return err

collector/os.go

@@ -1,5 +1,4 @@
-// returns data points from Win32_OperatingSystem
-// https://msdn.microsoft.com/en-us/library/aa394239 - Win32_OperatingSystem class
+// +build windows
 
 package collector
 
@@ -114,7 +113,7 @@ func NewOSCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *OSCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *OSCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting os metrics:", desc, err)
 		return err
@@ -122,6 +121,8 @@ func (c *OSCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_OperatingSystem docs:
+// - https://msdn.microsoft.com/en-us/library/aa394239 - Win32_OperatingSystem class
 type Win32_OperatingSystem struct {
 	FreePhysicalMemory      uint64
 	FreeSpaceInPagingFiles  uint64

collector/perflib.go

@@ -0,0 +1,100 @@
+package collector
+
+import (
+	"fmt"
+	"reflect"
+
+	perflibCollector "github.com/leoluk/perflib_exporter/collector"
+	"github.com/leoluk/perflib_exporter/perflib"
+	"github.com/prometheus/common/log"
+)
+
+func getPerflibSnapshot() (map[string]*perflib.PerfObject, error) {
+	objects, err := perflib.QueryPerformanceData("Global")
+	if err != nil {
+		return nil, err
+	}
+
+	indexed := make(map[string]*perflib.PerfObject)
+	for _, obj := range objects {
+		indexed[obj.Name] = obj
+	}
+	return indexed, nil
+}
+
+func unmarshalObject(obj *perflib.PerfObject, vs interface{}) error {
+	if obj == nil {
+		return fmt.Errorf("counter not found")
+	}
+	rv := reflect.ValueOf(vs)
+	if rv.Kind() != reflect.Ptr || rv.IsNil() {
+		return fmt.Errorf("%v is nil or not a pointer to slice", reflect.TypeOf(vs))
+	}
+	ev := rv.Elem()
+	if ev.Kind() != reflect.Slice {
+		return fmt.Errorf("%v is not slice", reflect.TypeOf(vs))
+	}
+
+	// Ensure sufficient length
+	if ev.Cap() < len(obj.Instances) {
+		nvs := reflect.MakeSlice(ev.Type(), len(obj.Instances), len(obj.Instances))
+		ev.Set(nvs)
+	}
+
+	for idx, instance := range obj.Instances {
+		target := ev.Index(idx)
+		rt := target.Type()
+
+		counters := make(map[string]*perflib.PerfCounter, len(instance.Counters))
+		for _, ctr := range instance.Counters {
+			if ctr.Def.IsBaseValue && !ctr.Def.IsNanosecondCounter {
+				counters[ctr.Def.Name+"_Base"] = ctr
+			} else {
+				counters[ctr.Def.Name] = ctr
+			}
+		}
+
+		for i := 0; i < target.NumField(); i++ {
+			f := rt.Field(i)
+			tag := f.Tag.Get("perflib")
+			if tag == "" {
+				continue
+			}
+
+			ctr, found := counters[tag]
+			if !found {
+				log.Debugf("missing counter %q, have %v", tag, counterMapKeys(counters))
+				continue
+			}
+			if !target.Field(i).CanSet() {
+				return fmt.Errorf("tagged field %v cannot be written to", f.Name)
+			}
+			if fieldType := target.Field(i).Type(); fieldType != reflect.TypeOf((*float64)(nil)).Elem() {
+				return fmt.Errorf("tagged field %v has wrong type %v, must be float64", f.Name, fieldType)
+			}
+
+			switch ctr.Def.CounterType {
+			case perflibCollector.PERF_ELAPSED_TIME:
+				target.Field(i).SetFloat(float64(ctr.Value-windowsEpoch) / float64(obj.Frequency))
+			case perflibCollector.PERF_100NSEC_TIMER, perflibCollector.PERF_PRECISION_100NS_TIMER:
+				target.Field(i).SetFloat(float64(ctr.Value) * ticksToSecondsScaleFactor)
+			default:
+				target.Field(i).SetFloat(float64(ctr.Value))
+			}
+		}
+
+		if instance.Name != "" && target.FieldByName("Name").CanSet() {
+			target.FieldByName("Name").SetString(instance.Name)
+		}
+	}
+
+	return nil
+}
+
+func counterMapKeys(m map[string]*perflib.PerfCounter) []string {
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	return keys
+}

collector/perflib_test.go

@@ -0,0 +1,125 @@
+package collector
+
+import (
+	"reflect"
+	"testing"
+
+	perflibCollector "github.com/leoluk/perflib_exporter/collector"
+	"github.com/leoluk/perflib_exporter/perflib"
+)
+
+type simple struct {
+	ValA float64 `perflib:"Something"`
+	ValB float64 `perflib:"Something Else"`
+}
+
+func TestUnmarshalPerflib(t *testing.T) {
+	cases := []struct {
+		name string
+		obj  *perflib.PerfObject
+
+		expectedOutput []simple
+		expectError    bool
+	}{
+		{
+			name:           "nil check",
+			obj:            nil,
+			expectedOutput: []simple{},
+			expectError:    true,
+		},
+		{
+			name: "Simple",
+			obj: &perflib.PerfObject{
+				Instances: []*perflib.PerfInstance{
+					{
+						Counters: []*perflib.PerfCounter{
+							{
+								Def: &perflib.PerfCounterDef{
+									Name:        "Something",
+									CounterType: perflibCollector.PERF_COUNTER_COUNTER,
+								},
+								Value: 123,
+							},
+						},
+					},
+				},
+			},
+			expectedOutput: []simple{{ValA: 123}},
+			expectError:    false,
+		},
+		{
+			name: "Multiple properties",
+			obj: &perflib.PerfObject{
+				Instances: []*perflib.PerfInstance{
+					{
+						Counters: []*perflib.PerfCounter{
+							{
+								Def: &perflib.PerfCounterDef{
+									Name:        "Something",
+									CounterType: perflibCollector.PERF_COUNTER_COUNTER,
+								},
+								Value: 123,
+							},
+							{
+								Def: &perflib.PerfCounterDef{
+									Name:        "Something Else",
+									CounterType: perflibCollector.PERF_COUNTER_COUNTER,
+								},
+								Value: 256,
+							},
+						},
+					},
+				},
+			},
+			expectedOutput: []simple{{ValA: 123, ValB: 256}},
+			expectError:    false,
+		},
+		{
+			name: "Multiple instances",
+			obj: &perflib.PerfObject{
+				Instances: []*perflib.PerfInstance{
+					{
+						Counters: []*perflib.PerfCounter{
+							{
+								Def: &perflib.PerfCounterDef{
+									Name:        "Something",
+									CounterType: perflibCollector.PERF_COUNTER_COUNTER,
+								},
+								Value: 321,
+							},
+						},
+					},
+					{
+						Counters: []*perflib.PerfCounter{
+							{
+								Def: &perflib.PerfCounterDef{
+									Name:        "Something",
+									CounterType: perflibCollector.PERF_COUNTER_COUNTER,
+								},
+								Value: 231,
+							},
+						},
+					},
+				},
+			},
+			expectedOutput: []simple{{ValA: 321}, {ValA: 231}},
+			expectError:    false,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			output := make([]simple, 0)
+			err := unmarshalObject(c.obj, &output)
+			if err != nil && !c.expectError {
+				t.Errorf("Did not expect error, got %q", err)
+			}
+			if err == nil && c.expectError {
+				t.Errorf("Expected an error, but got ok")
+			}
+
+			if err == nil && !reflect.DeepEqual(output, c.expectedOutput) {
+				t.Errorf("Output mismatch, expected %+v, got %+v", c.expectedOutput, output)
+			}
+		})
+	}
+}

collector/process.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_PerfRawData_PerfProc_Process
-// https://msdn.microsoft.com/en-us/library/aa394323(v=vs.85).aspx - Win32_PerfRawData_PerfProc_Process class
+// +build windows
+
 package collector
 
 import (
@@ -135,7 +135,7 @@ func NewProcessCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *ProcessCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *ProcessCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting process metrics:", desc, err)
 		return err
@@ -143,6 +143,8 @@ func (c *ProcessCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_PerfRawData_PerfProc_Process docs:
+// - https://msdn.microsoft.com/en-us/library/aa394323(v=vs.85).aspx
 type Win32_PerfRawData_PerfProc_Process struct {
 	Name                    string
 	CreatingProcessID       uint32
@@ -191,7 +193,9 @@ func (c *ProcessCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Des
 
 	var dst_wp []WorkerProcess
 	q_wp := queryAll(&dst_wp)
-	wmi.QueryNamespace(q_wp, &dst_wp, "root\\WebAdministration")
+	if err := wmi.QueryNamespace(q_wp, &dst_wp, "root\\WebAdministration"); err != nil {
+		log.Debugf("Could not query WebAdministration namespace for IIS worker processes: %v. Skipping", err)
+	}
 
 	for _, process := range dst {
 

collector/service.go

@@ -1,5 +1,5 @@
-// returns data points from Win32_Service
-// https://msdn.microsoft.com/en-us/library/aa394418(v=vs.85).aspx - Win32_Service class
+// +build windows
+
 package collector
 
 import (
@@ -64,7 +64,7 @@ func NewserviceCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *serviceCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *serviceCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting service metrics:", desc, err)
 		return err
@@ -72,6 +72,8 @@ func (c *serviceCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_Service docs:
+// - https://msdn.microsoft.com/en-us/library/aa394418(v=vs.85).aspx
 type Win32_Service struct {
 	Name      string
 	State     string

collector/system.go

@@ -1,5 +1,4 @@
-// returns data points from Win32_PerfRawData_PerfOS_System class
-// https://web.archive.org/web/20050830140516/http://msdn.microsoft.com/library/en-us/wmisdk/wmi/win32_perfrawdata_perfos_system.asp
+// +build windows
 
 package collector
 
@@ -70,7 +69,7 @@ func NewSystemCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *SystemCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *SystemCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting system metrics:", desc, err)
 		return err
@@ -78,6 +77,8 @@ func (c *SystemCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_PerfRawData_PerfOS_System docs:
+// - https://web.archive.org/web/20050830140516/http://msdn.microsoft.com/library/en-us/wmisdk/wmi/win32_perfrawdata_perfos_system.asp
 type Win32_PerfRawData_PerfOS_System struct {
 	ContextSwitchesPersec     uint32
 	ExceptionDispatchesPersec uint32

collector/tcp.go

@@ -1,6 +1,4 @@
-// returns data points from Win32_PerfRawData_Tcpip_TCPv4
-
-// https://msdn.microsoft.com/en-us/library/aa394341(v=vs.85).aspx (Win32_PerfRawData_Tcpip_TCPv4 class)
+// +build windows
 
 package collector
 
@@ -92,7 +90,7 @@ func NewTCPCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *TCPCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *TCPCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collect(ch); err != nil {
 		log.Error("failed collecting tcp metrics:", desc, err)
 		return err
@@ -100,6 +98,8 @@ func (c *TCPCollector) Collect(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
+// Win32_PerfRawData_Tcpip_TCPv4 docs
+// - https://msdn.microsoft.com/en-us/library/aa394341(v=vs.85).aspx
 type Win32_PerfRawData_Tcpip_TCPv4 struct {
 	ConnectionFailures          uint64
 	ConnectionsActive           uint64

collector/textfile.go

@@ -212,7 +212,7 @@ func (cr carriageReturnFilteringReader) Read(p []byte) (int, error) {
 }
 
 // Update implements the Collector interface.
-func (c *textFileCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *textFileCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	error := 0.0
 	mtimes := map[string]time.Time{}
 
@@ -237,9 +237,17 @@ fileLoop:
 			continue
 		}
 		var parser expfmt.TextParser
-		r := utfbom.SkipOnly(carriageReturnFilteringReader{r: file})
+		r, encoding := utfbom.Skip(carriageReturnFilteringReader{r: file})
+		if err = checkBOM(encoding); err != nil {
+			log.Errorf("Invalid file encoding detected in %s: %s - file must be UTF8", path, err.Error())
+			error = 1.0
+			continue
+		}
 		parsedFamilies, err := parser.TextToMetricFamilies(r)
-		file.Close()
+		closeErr := file.Close()
+		if closeErr != nil {
+			log.Warnf("Error closing file: %v", err)
+		}
 		if err != nil {
 			log.Errorf("Error parsing %q: %v", path, err)
 			error = 1.0
@@ -281,3 +289,11 @@ fileLoop:
 	)
 	return nil
 }
+
+func checkBOM(encoding utfbom.Encoding) error {
+	if encoding == utfbom.Unknown || encoding == utfbom.UTF8 {
+		return nil
+	}
+
+	return fmt.Errorf(encoding.String())
+}

collector/textfile_test.go

@@ -1,14 +1,15 @@
 package collector
 
 import (
-	"testing"
-	"strings"
+	"github.com/dimchansky/utfbom"
 	"io/ioutil"
+	"strings"
+	"testing"
 )
 
 func TestCRFilter(t *testing.T) {
 	sr := strings.NewReader("line 1\r\nline 2")
-	cr := carriageReturnFilteringReader{ r: sr }
+	cr := carriageReturnFilteringReader{r: sr}
 	b, err := ioutil.ReadAll(cr)
 	if err != nil {
 		t.Error(err)
@@ -17,4 +18,30 @@ func TestCRFilter(t *testing.T) {
 	if string(b) != "line 1\nline 2" {
 		t.Errorf("Unexpected output %q", b)
 	}
-}
+}
+
+func TestCheckBOM(t *testing.T) {
+	testdata := []struct {
+		encoding utfbom.Encoding
+		err      string
+	}{
+		{utfbom.Unknown, ""},
+		{utfbom.UTF8, ""},
+		{utfbom.UTF16BigEndian, "UTF16BigEndian"},
+		{utfbom.UTF16LittleEndian, "UTF16LittleEndian"},
+		{utfbom.UTF32BigEndian, "UTF32BigEndian"},
+		{utfbom.UTF32LittleEndian, "UTF32LittleEndian"},
+	}
+	for _, d := range testdata {
+		err := checkBOM(d.encoding)
+		if d.err == "" && err != nil {
+			t.Error(err)
+		}
+		if d.err != "" && err == nil {
+			t.Errorf("Missing expected error %s", d.err)
+		}
+		if err != nil && !strings.Contains(err.Error(), d.err) {
+			t.Error(err)
+		}
+	}
+}

collector/thermalzone.go

@@ -0,0 +1,103 @@
+package collector
+
+import (
+	"github.com/StackExchange/wmi"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
+)
+
+func init() {
+	Factories["thermalzone"] = NewThermalZoneCollector
+}
+
+// A thermalZoneCollector is a Prometheus collector for WMI Win32_PerfRawData_Counters_ThermalZoneInformation metrics
+type thermalZoneCollector struct {
+	PercentPassiveLimit *prometheus.Desc
+	Temperature         *prometheus.Desc
+	ThrottleReasons     *prometheus.Desc
+}
+
+// NewThermalZoneCollector ...
+func NewThermalZoneCollector() (Collector, error) {
+	const subsystem = "thermalzone"
+	return &thermalZoneCollector{
+		Temperature: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "temperature_celsius"),
+			"(Temperature)",
+			[]string{
+				"name",
+			},
+			nil,
+		),
+		PercentPassiveLimit: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "percent_passive_limit"),
+			"(PercentPassiveLimit)",
+			[]string{
+				"name",
+			},
+			nil,
+		),
+		ThrottleReasons: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "throttle_reasons"),
+			"(ThrottleReasons)",
+			[]string{
+				"name",
+			},
+			nil,
+		),
+	}, nil
+}
+
+// Collect sends the metric values for each metric
+// to the provided prometheus Metric channel.
+func (c *thermalZoneCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
+	if desc, err := c.collect(ch); err != nil {
+		log.Error("failed collecting thermalzone metrics:", desc, err)
+		return err
+	}
+	return nil
+}
+
+// Win32_PerfRawData_Counters_ThermalZoneInformation docs:
+// https://wutils.com/wmi/root/cimv2/win32_perfrawdata_counters_thermalzoneinformation/
+type Win32_PerfRawData_Counters_ThermalZoneInformation struct {
+	Name string
+
+	HighPrecisionTemperature uint32
+	PercentPassiveLimit      uint32
+	ThrottleReasons          uint32
+}
+
+func (c *thermalZoneCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
+	var dst []Win32_PerfRawData_Counters_ThermalZoneInformation
+	q := queryAll(&dst)
+	if err := wmi.Query(q, &dst); err != nil {
+		return nil, err
+	}
+
+	for _, info := range dst {
+		//Divide by 10 and subtract 273.15 to convert decikelvin to celsius
+		ch <- prometheus.MustNewConstMetric(
+			c.Temperature,
+			prometheus.GaugeValue,
+			(float64(info.HighPrecisionTemperature)/10.0)-273.15,
+			info.Name,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.PercentPassiveLimit,
+			prometheus.GaugeValue,
+			float64(info.PercentPassiveLimit),
+			info.Name,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.ThrottleReasons,
+			prometheus.GaugeValue,
+			float64(info.ThrottleReasons),
+			info.Name,
+		)
+	}
+
+	return nil, nil
+}

collector/vmware.go

@@ -1,4 +1,5 @@
-// returns data points from Win32_PerfRawData_vmGuestLib_VMem and Win32_PerfRawData_vmGuestLib_VCPU
+// +build windows
+
 package collector
 
 import (
@@ -37,6 +38,7 @@ type VmwareCollector struct {
 	HostProcessorSpeedMHz *prometheus.Desc
 }
 
+// NewVmwareCollector constructs a new VmwareCollector
 func NewVmwareCollector() (Collector, error) {
 	const subsystem = "vmware"
 	return &VmwareCollector{
@@ -160,7 +162,7 @@ func NewVmwareCollector() (Collector, error) {
 
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *VmwareCollector) Collect(ch chan<- prometheus.Metric) error {
+func (c *VmwareCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
 	if desc, err := c.collectMem(ch); err != nil {
 		log.Error("failed collecting vmware memory metrics:", desc, err)
 		return err

collector/wmi.go

@@ -4,27 +4,9 @@ import (
 	"bytes"
 	"reflect"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/log"
 )
 
-// ...
-const (
-	Namespace = "wmi"
-
-	// Conversion factors
-	ticksToSecondsScaleFactor = 1 / 1e7
-)
-
-// Factories ...
-var Factories = make(map[string]func() (Collector, error))
-
-// Collector is the interface a collector has to implement.
-type Collector interface {
-	// Get new metrics and expose them via prometheus registry.
-	Collect(ch chan<- prometheus.Metric) (err error)
-}
-
 func className(src interface{}) string {
 	s := reflect.Indirect(reflect.ValueOf(src))
 	t := s.Type()

contrib/console_templates/wmi-overview.html

@@ -0,0 +1,140 @@
+{{ template "head" . }}
+
+{{ template "prom_content_head" . }}
+  <h1>Node Overview - {{ reReplaceAll "(.*?://)([^:/]+?)(:\\d+)?/.*" "$2" .Params.instance }}</h1>
+
+  <h3>CPU Usage</h3>
+  <div id="cpuGraph"></div>
+  <script>
+  new PromConsole.Graph({
+    node: document.querySelector("#cpuGraph"),
+    expr: "sum by (mode)(irate(wmi_cpu_time_total{job='node',instance='{{ .Params.instance }}',mode!='idle'}[5m]))",
+    renderer: 'area',
+    max: {{ with printf "count(count by (cpu)(wmi_cpu_time_total{job='node',instance='%s'}))" .Params.instance | query }}{{ . | first | value }}{{ else}}undefined{{end}},
+    yAxisFormatter: PromConsole.NumberFormatter.humanizeNoSmallPrefix,
+    yHoverFormatter: PromConsole.NumberFormatter.humanizeNoSmallPrefix,
+    yTitle: 'Cores'
+  })
+  </script>
+
+  <h3>Network Utilization</h3>
+  <div id="networkioGraph"></div>
+  <script>
+  new PromConsole.Graph({
+    node: document.querySelector("#networkioGraph"),
+    expr: [
+      "irate(wmi_net_bytes_sent_total{job='node',instance='{{ .Params.instance }}',nic!~'^isatap_ec2_internal'}[5m])",
+      "irate(wmi_net_bytes_received_total{job='node',instance='{{ .Params.instance }}',nic!~'^isatap_ec2_internal'}[5m])",
+    ],
+    min: 0,
+    name: [ 'sent', 'received' ],
+    yAxisFormatter: PromConsole.NumberFormatter.humanizeNoSmallPrefix,
+    yHoverFormatter: PromConsole.NumberFormatter.humanizeNoSmallPrefix,
+    yUnits: "B",
+    yTitle: 'Network IO'
+  })
+  </script>
+
+  <h3>Disk I/O Utilization</h3>
+  <div id="diskioGraph"></div>
+  <script>
+  new PromConsole.Graph({
+    node: document.querySelector("#diskioGraph"),
+    expr: [
+      "100 - irate(wmi_logical_disk_idle_seconds_total{job='node',instance='{{ .Params.instance }}',volume!~'^HarddiskVolume.*$'}[5m]) * 100",
+    ],
+    min: 0,
+    name: '[[ volume ]]',
+    yAxisFormatter: PromConsole.NumberFormatter.humanizeNoSmallPrefix,
+    yHoverFormatter: PromConsole.NumberFormatter.humanizeNoSmallPrefix,
+    yUnits: "%",
+    yTitle: 'Disk I/O Utilization'
+  })
+  </script>
+
+  <h3>Memory</h3>
+  <div id="memoryGraph"></div>
+  <script>
+  new PromConsole.Graph({
+    node: document.querySelector("#memoryGraph"),
+    renderer: 'area',
+    expr: [
+      "wmi_cs_physical_memory_bytes{job='node',instance='{{ .Params.instance }}'}",
+      "wmi_os_physical_memory_free_bytes{job='node',instance='{{ .Params.instance }}'}",
+      "wmi_cs_physical_memory__bytes{job='node',instance='{{ .Params.instance }}'} - wmi_os_physical_memory_free_bytes{job='node',instance='{{.Params.instance}}'}",
+      "wmi_os_virtual_memory_bytes{job='node',instance='{{ .Params.instance }}'}",
+    ],
+    name: ["Physical", "Free", "Used", "Virtual"],
+    min: 0,
+    yUnits: "B",
+    yAxisFormatter: PromConsole.NumberFormatter.humanize1024,
+    yHoverFormatter: PromConsole.NumberFormatter.humanize1024,
+    yTitle: 'Memory'
+  })
+  </script>
+
+{{ template "prom_right_table_head" }}
+  <tr><th colspan="2">Overview</th></tr>
+  <tr>
+    <td>User CPU</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "sum(irate(wmi_cpu_time_total{job='node',instance='%s',mode='user'}[5m])) * 100 / count(count by (cpu)(wmi_cpu_time_total{job='node',instance='%s'}))" .Params.instance .Params.instance) "%" "printf.1f") }}</td>
+  </tr>
+  <tr>
+    <td>Privileged CPU</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "sum(irate(wmi_cpu_time_total{job='node',instance='%s',mode='privileged'}[5m])) * 100 / count(count by (cpu)(wmi_cpu_time_total{job='node',instance='%s'}))" .Params.instance .Params.instance) "%" "printf.1f") }}</td>
+  </tr>
+  <tr>
+    <td>Memory Total</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "wmi_cs_physical_memory_bytes{job='node',instance='%s'}" .Params.instance) "B" "humanize1024") }}</td>
+  </tr>
+  <tr>
+    <td>Memory Free</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "wmi_os_physical_memory_free_bytes{job='node',instance='%s'}" .Params.instance) "B" "humanize1024") }}</td>
+  </tr>
+<tr>
+  <th colspan="2">Network</th>
+</tr>
+{{ range printf "wmi_net_bytes_received_total{job='node',instance='%s',nic!='isatap_ec2_internal'}" .Params.instance | query | sortByLabel "nic" }}
+  <tr>
+    <td>{{ .Labels.nic }} Received</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "irate(wmi_net_bytes_received_total{job='node',instance='%s',nic='%s'}[5m])" .Labels.instance .Labels.nic) "B/s" "humanize") }}</td>
+  </tr>
+  <tr>
+    <td>{{ .Labels.nic }} Transmitted</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "irate(wmi_net_bytes_sent_total{job='node',instance='%s',nic='%s'}[5m])" .Labels.instance .Labels.nic) "B/s" "humanize") }}</td>
+  </tr>
+{{ end }}
+</tr>
+<tr>
+  <th colspan="2">Disks</th>
+</tr>
+{{ range printf "wmi_logical_disk_size_bytes{job='node',instance='%s',volume!~'^HarddiskVolume.*$'}" .Params.instance | query | sortByLabel "volume" }}
+  <tr>
+    <td>{{ .Labels.volume }} Utilization</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "100 - irate(wmi_logical_disk_idle_seconds_total{job='node',instance='%s',volume='%s'}[5m]) * 100" .Labels.instance .Labels.volume) "%" "printf.1f") }}</td>
+  </tr>
+{{ end }}
+{{ range printf "wmi_logical_disk_size_bytes{job='node',instance='%s',volume!~'^HarddiskVolume.*$'}" .Params.instance | query | sortByLabel "volume" }}
+  <tr>
+    <td>{{ .Labels.volume }} Throughput</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "irate(wmi_logical_disk_read_bytes_total{job='node',instance='%s',volume='%s'}[5m]) + irate(wmi_logical_disk_write_bytes_total{job='node',instance='%s',volume='%s'}[5m])" .Labels.instance .Labels.volume .Labels.instance .Labels.volume) "B/s" "humanize") }}</td>
+  </tr>
+{{ end }}
+<tr>
+  <th colspan="2">Filesystem Fullness</th>
+</tr>
+{{ define "roughlyNearZero" }}
+{{ if gt .1 . }}~0{{ else }}{{ printf "%.1f" . }}{{ end }}
+{{ end }}
+{{ range printf "wmi_logical_disk_size_bytes{job='node',instance='%s',volume!~'^HarddiskVolume.*$'}" .Params.instance | query | sortByLabel "volume" }}
+  <tr>
+    <td>{{ .Labels.volume }}</td>
+    <td>{{ template "prom_query_drilldown" (args (printf "100 - wmi_logical_disk_free_bytes{job='node',instance='%s',volume='%s'} / wmi_logical_disk_size_bytes{job='node'} * 100" .Labels.instance .Labels.volume) "%" "roughlyNearZero") }}</td>
+  </tr>
+{{ end }}
+</tr>
+{{ template "prom_right_table_tail" }}
+
+{{ template "prom_content_tail" . }}
+
+{{ template "tail" }}

docs/README.md

@@ -9,6 +9,7 @@ This directory contains documentation of the collectors in the WMI exporter, wit
 - [`hyperv`](collector.hyperv.md)
 - [`iis`](collector.iis.md)
 - [`logical_disk`](collector.logical_disk.md)
+- [`memory`](collector.memory.md)
 - [`msmq`](collector.msmq.md)
 - [`mssql`](collector.mssql.md)
 - [`netframework_clrexceptions`](collector.netframework_clrexceptions.md)
@@ -26,4 +27,4 @@ This directory contains documentation of the collectors in the WMI exporter, wit
 - [`system`](collector.system.md)
 - [`tcp`](collector.tcp.md)
 - [`textfile`](collector.textfile.md)
-- [`vmware`](collector.vmware.md)
+- [`vmware`](collector.vmware.md)

docs/collector-template.md

@@ -2,7 +2,9 @@
 
 The %name% collector exposes metrics about ...
 
-Metric name prefix | `%name%`
+|||
+-|-
+Metric name prefix  | `%name%`
 Classes             | [`...`](https://msdn.microsoft.com/en-us/library/...)
 Enabled by default? | Yes/No
 

docs/collector.ad.md

@@ -2,7 +2,9 @@
 
 The ad collector exposes metrics about a Active Directory Domain Services domain controller
 
-Metric name prefix | `ad`
+|||
+-|-
+Metric name prefix  | `ad`
 Classes             | [`Win32_PerfRawData_DirectoryServices_DirectoryServices`](https://msdn.microsoft.com/en-us/library/ms803980.aspx)
 Enabled by default? | No
 

docs/collector.container.md

@@ -0,0 +1,42 @@
+# container collector
+
+The container collector exposes metrics about containers running on system
+
+|||
+-|-
+Metric name prefix  | `container`
+Enabled by default? | No
+
+## Flags
+
+None
+
+## Metrics
+
+Name | Description | Type | Labels
+-----|-------------|------|-------
+`wmi_container_available` | Available | counter | `container_id`
+`wmi_container_count` | Number of containers | gauge | `container_id`
+`wmi_container_cpu_usage_seconds_kernelmode` | Run time in Kernel mode in Seconds | counter | `container_id`
+`wmi_container_cpu_usage_seconds_usermode` | Run Time in User mode in Seconds | counter | `container_id`
+`wmi_container_cpu_usage_seconds_total` | Total Run time in Seconds | counter | `container_id`
+`wmi_container_memory_usage_commit_bytes` | Memory Usage Commit Bytes | gauge | `container_id`
+`wmi_container_memory_usage_commit_peak_bytes` | Memory Usage Commit Peak Bytes | gauge | `container_id`
+`wmi_container_memory_usage_private_working_set_bytes` | Memory Usage Private Working Set Bytes | gauge | `container_id`
+`wmi_container_network_receive_bytes_total` | Bytes Received on Interface | counter | `container_id`, `interface`
+`wmi_container_network_receive_packets_total` | Packets Received on Interface | counter | `container_id`, `interface`
+`wmi_container_network_receive_packets_dropped_total` | Dropped Incoming Packets on Interface | counter | `container_id`, `interface`
+`wmi_container_network_transmit_bytes_total` | Bytes Sent on Interface | counter | `container_id`, `interface`
+`wmi_container_network_transmit_packets_total` | Packets Sent on Interface | counter | `container_id`, `interface`
+`wmi_container_network_transmit_packets_dropped_total` | Dropped Outgoing Packets on Interface | counter | `container_id`, `interface`
+
+### Example metric
+_wmi_container_network_receive_bytes_total{container_id="docker://1bd30e8b8ac28cbd76a9b697b4d7bb9d760267b0733d1bc55c60024e98d1e43e",interface="822179E7-002C-4280-ABBA-28BCFE401826"} 9.3305343e+07_
+
+This metric means that total _9.3305343e+07_ bytes received on interface _822179E7-002C-4280-ABBA-28BCFE401826_ for container _docker://1bd30e8b8ac28cbd76a9b697b4d7bb9d760267b0733d1bc55c60024e98d1e43e_
+
+## Useful queries
+_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+
+## Alerting examples
+_This collector does not yet have alerting examples, we would appreciate your help adding them!_

docs/collector.cpu.md

@@ -2,8 +2,11 @@
 
 The cpu collector exposes metrics about CPU usage
 
-Metric name prefix | `cpu`
-Classes             | [`Win32_PerfRawData_PerfOS_Processor`](https://msdn.microsoft.com/en-us/library/aa394317(v=vs.90).aspx)
+|||
+-|-
+Metric name prefix  | `cpu`
+Data source         | Perflib
+Counters            | `ProcessorInformation` (Windows Server 2008R2 and later) `Processor` (older versions)
 Enabled by default? | Yes
 
 ## Flags
@@ -11,6 +14,7 @@ Enabled by default? | Yes
 None
 
 ## Metrics
+These metrics are available on all versions of Windows:
 
 Name | Description | Type | Labels
 -----|-------------|------|-------
@@ -19,6 +23,16 @@ Name | Description | Type | Labels
 `wmi_cpu_interrupts_total` | Total number of received and serviced hardware interrupts | counter | `core`
 `wmi_cpu_dpcs_total` | Total number of received and serviced deferred procedure calls (DPCs) | counter | `core`
 
+These metrics are only exposed on Windows Server 2008R2 and later:
+
+Name | Description | Type | Labels
+-----|-------------|------|-------
+`wmi_cpu_clock_interrupts_total` | Total number of received and serviced clock tick interrupts | `core`
+`wmi_cpu_idle_break_events_total` | Total number of time processor was woken from idle | `core`
+`wmi_cpu_parking_status` | Parking Status represents whether a processor is parked or not | `gauge`
+`wmi_cpu_core_frequency_mhz` | Core frequency in megahertz | `gauge`
+`wmi_cpu_processor_performance` | Processor Performance is the average performance of the processor while it is executing instructions, as a percentage of the nominal performance of the processor. On some processors, Processor Performance may exceed 100% | `gauge`
+
 ### Example metric
 _This collector does not yet have explained examples, we would appreciate your help adding them!_
 

docs/collector.cs.md

@@ -2,7 +2,9 @@
 
 The cs collector exposes metrics detailing the hardware of the computer system
 
-Metric name prefix | `cs`
+|||
+-|-
+Metric name prefix  | `cs`
 Classes             | [`Win32_ComputerSystem`](https://msdn.microsoft.com/en-us/library/aa394102)
 Enabled by default? | Yes
 

docs/collector.dns.md

@@ -2,7 +2,9 @@
 
 The dns collector exposes metrics about the DNS server
 
-Metric name prefix | `dns`
+|||
+-|-
+Metric name prefix  | `dns`
 Classes             | [`Win32_PerfRawData_DNS_DNS`](https://technet.microsoft.com/en-us/library/cc977686.aspx)
 Enabled by default? | No
 

docs/collector.hyperv.md

@@ -2,8 +2,10 @@
 
 The hyperv collector exposes metrics about the Hyper-V hypervisor
 
-Metric name prefix | `hyperv`
-Classes             | `Win32_PerfRawData_VmmsVirtualMachineStats_HyperVVirtualMachineHealthSummary`, `Win32_PerfRawData_VidPerfProvider_HyperVVMVidPartition`, `Win32_PerfRawData_HvStats_HyperVHypervisorRootPartition`, `Win32_PerfRawData_HvStats_HyperVHypervisor`, `Win32_PerfRawData_HvStats_HyperVHypervisorRootVirtualProcessor`, `Win32_PerfRawData_HvStats_HyperVHypervisorVirtualProcessor`, `Win32_PerfRawData_NvspSwitchStats_HyperVVirtualSwitch`, `Win32_PerfRawData_EthernetPerfProvider_HyperVLegacyNetworkAdapter`, `Win32_PerfRawData_Counters_HyperVVirtualStorageDevice`, `Win32_PerfRawData_NvspNicStats_HyperVVirtualNetworkAdapter`
+|||
+-|-
+Metric name prefix  | `hyperv`
+Classes             | `Win32_PerfRawData_VmmsVirtualMachineStats_HyperVVirtualMachineHealthSummary`<br/>`Win32_PerfRawData_VidPerfProvider_HyperVVMVidPartition`<br/>`Win32_PerfRawData_HvStats_HyperVHypervisorRootPartition`<br/>`Win32_PerfRawData_HvStats_HyperVHypervisor`<br/>`Win32_PerfRawData_HvStats_HyperVHypervisorRootVirtualProcessor`<br/>`Win32_PerfRawData_HvStats_HyperVHypervisorVirtualProcessor`<br/>`Win32_PerfRawData_NvspSwitchStats_HyperVVirtualSwitch`<br/>`Win32_PerfRawData_EthernetPerfProvider_HyperVLegacyNetworkAdapter`<br/>`Win32_PerfRawData_Counters_HyperVVirtualStorageDevice`<br/>`Win32_PerfRawData_NvspNicStats_HyperVVirtualNetworkAdapter`
 Enabled by default? | No
 
 ## Flags

docs/collector.iis.md

@@ -2,8 +2,10 @@
 
 The iis collector exposes metrics about the IIS server
 
-Metric name prefix | `iis`
-Classes             | `Win32_PerfRawData_W3SVC_WebService`, `Win32_PerfRawData_APPPOOLCountersProvider_APPPOOLWAS`, `Win32_PerfRawData_W3SVCW3WPCounterProvider_W3SVCW3WP`, `Win32_PerfRawData_W3SVC_WebServiceCache`
+|||
+-|-
+Metric name prefix  | `iis`
+Classes             | `Win32_PerfRawData_W3SVC_WebService`<br/>`Win32_PerfRawData_APPPOOLCountersProvider_APPPOOLWAS`<br/>`Win32_PerfRawData_W3SVCW3WPCounterProvider_W3SVCW3WP`<br/>`Win32_PerfRawData_W3SVC_WebServiceCache`
 Enabled by default? | No
 
 ## Flags

docs/collector.logical_disk.md

@@ -2,7 +2,9 @@
 
 The logical_disk collector exposes metrics about logical disks (in contrast to physical disks)
 
-Metric name prefix | `logical_disk`
+|||
+-|-
+Metric name prefix  | `logical_disk`
 Classes             | [`Win32_PerfRawData_PerfDisk_LogicalDisk`](https://msdn.microsoft.com/en-us/windows/hardware/aa394307(v=vs.71))
 Enabled by default? | Yes
 

docs/collector.memory.md

@@ -2,6 +2,8 @@
 
 The memory collector exposes metrics about system memory usage
 
+|||
+-|-
 Metric name prefix  | `memory`
 Classes             | `Win32_PerfRawData_PerfOS_Memory`
 Enabled by default? | Yes

docs/collector.msmq.md

@@ -2,7 +2,9 @@
 
 The msmq collector exposes metrics about the queues on a MSMQ server
 
-Metric name prefix | `msmq`
+|||
+-|-
+Metric name prefix  | `msmq`
 Classes             | `Win32_PerfRawData_MSMQ_MSMQQueue`
 Enabled by default? | No
 

docs/collector.mssql.md

@@ -2,15 +2,17 @@
 
 The mssql collector exposes metrics about the MSSQL server
 
-Metric name prefix | `mssql`
-Classes             | [`Win32_PerfRawData_MSSQLSERVER_SQLServerAccessMethods`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-access-methods-object), [`Win32_PerfRawData_MSSQLSERVER_SQLServerAvailabilityReplica`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-availability-replica), [`Win32_PerfRawData_MSSQLSERVER_SQLServerBufferManager`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-buffer-manager-object), [`Win32_PerfRawData_MSSQLSERVER_SQLServerDatabaseReplica`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-database-replica), [`Win32_PerfRawData_MSSQLSERVER_SQLServerDatabases`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-databases-object?view=sql-server-2017), [`Win32_PerfRawData_MSSQLSERVER_SQLServerGeneralStatistics`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-general-statistics-object), [`Win32_PerfRawData_MSSQLSERVER_SQLServerLocks`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-locks-object), [`Win32_PerfRawData_MSSQLSERVER_SQLServerMemoryManager`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-memory-manager-object), [`Win32_PerfRawData_MSSQLSERVER_SQLServerSQLStatistics`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-sql-statistics-object)
+|||
+-|-
+Metric name prefix  | `mssql`
+Classes             | [`Win32_PerfRawData_MSSQLSERVER_SQLServerAccessMethods`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-access-methods-object)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerAvailabilityReplica`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-availability-replica)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerBufferManager`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-buffer-manager-object)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerDatabaseReplica`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-database-replica)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerDatabases`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-databases-object?view=sql-server-2017)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerGeneralStatistics`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-general-statistics-object)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerLocks`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-locks-object)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerMemoryManager`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-memory-manager-object)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerSQLStatistics`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-sql-statistics-object)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerSQLErrors`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-sql-errors-object)<br/>[`Win32_PerfRawData_MSSQLSERVER_SQLServerTransactions`](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-transactions-object)
 Enabled by default? | No
 
 ## Flags
 
 ### `--collectors.mssql.classes-enabled`
 
-Comma-separated list of MSSQL WMI classes to use. Supported values are `accessmethods`, `availreplica`, `bufman`, `databases`, `dbreplica`, `genstats`, `locks`, `memmgr` and `sqlstats`.
+Comma-separated list of MSSQL WMI classes to use. Supported values are `accessmethods`, `availreplica`, `bufman`, `databases`, `dbreplica`, `genstats`, `locks`, `memmgr`, `sqlstats`, `sqlerrors` and `transactions`.
 
 ### `--collectors.mssql.class-print`
 
@@ -228,6 +230,20 @@ Name | Description | Type | Labels
 `wmi_mssql_sqlstats_sql_compilations` | _Not yet documented_ | counter | `instance`
 `wmi_mssql_sqlstats_sql_recompilations` | _Not yet documented_ | counter | `instance`
 `wmi_mssql_sqlstats_unsafe_auto_parameterization_attempts` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_sql_errors_total` | _Not yet documented_ | counter | `instance`, `resource`
+`wmi_mssql_transactions_tempdb_free_space_bytes` | _Not yet documented_ | gauge | `instance`
+`wmi_mssql_transactions_longest_transaction_running_seconds` | _Not yet documented_ | gauge | `instance`
+`wmi_mssql_transactions_nonsnapshot_version_active_total` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_transactions_snapshot_active_total` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_transactions_active_total` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_transactions_update_conflicts_total` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_transactions_update_snapshot_active_total` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_transactions_version_cleanup_rate_bytes` | _Not yet documented_ | gauge | `instance`
+`wmi_mssql_transactions_version_generation_rate_bytes` | _Not yet documented_ | gauge | `instance`
+`wmi_mssql_transactions_version_store_size_bytes` | _Not yet documented_ | gauge | `instance`
+`wmi_mssql_transactions_version_store_units` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_transactions_version_store_creation_units` | _Not yet documented_ | counter | `instance`
+`wmi_mssql_transactions_version_store_truncation_units` | _Not yet documented_ | counter | `instance`
 
 ### Example metric
 _This collector does not yet have explained examples, we would appreciate your help adding them!_

docs/collector.net.md

@@ -2,7 +2,9 @@
 
 The net collector exposes metrics about network interfaces
 
-Metric name prefix | `net`
+|||
+-|-
+Metric name prefix  | `net`
 Classes             | [`Win32_PerfRawData_Tcpip_NetworkInterface`](https://technet.microsoft.com/en-us/security/aa394340(v=vs.80))
 Enabled by default? | Yes
 

docs/collector.netframework_clrexceptions.md

@@ -2,7 +2,9 @@
 
 The netframework_clrexceptions collector exposes metrics about CLR exceptions in the dotnet framework.
 
-Metric name prefix | `netframework_clrexceptions`
+|||
+-|-
+Metric name prefix  | `netframework_clrexceptions`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRExceptions`
 Enabled by default? | No
 

docs/collector.netframework_clrinterop.md

@@ -2,7 +2,9 @@
 
 The netframework_clrinterop collector exposes metrics about interop between the dotnet framework and outside components.
 
-Metric name prefix | `netframework_clrinterop`
+|||
+-|-
+Metric name prefix  | `netframework_clrinterop`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRInterop`
 Enabled by default? | No
 

docs/collector.netframework_clrjit.md

@@ -2,7 +2,9 @@
 
 The netframework_clrjit collector exposes metrics about the dotnet Just-in-Time compiler.
 
-Metric name prefix | `netframework_clrjit`
+|||
+-|-
+Metric name prefix  | `netframework_clrjit`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRJit`
 Enabled by default? | No
 

docs/collector.netframework_clrloading.md

@@ -2,7 +2,9 @@
 
 The netframework_clrloading collector exposes metrics about the dotnet loader.
 
-Metric name prefix | `netframework_clrloading`
+|||
+-|-
+Metric name prefix  | `netframework_clrloading`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRLoading`
 Enabled by default? | No
 

docs/collector.netframework_clrlocksandthreads.md

@@ -2,7 +2,9 @@
 
 The netframework_clrlocksandthreads collector exposes metrics about locks and threads in dotnet applications.
 
-Metric name prefix | `netframework_clrlocksandthreads`
+|||
+-|-
+Metric name prefix  | `netframework_clrlocksandthreads`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRLocksAndThreads`
 Enabled by default? | No
 

docs/collector.netframework_clrmemory.md

@@ -2,7 +2,9 @@
 
 The netframework_clrmemory collector exposes metrics about memory in dotnet applications.
 
-Metric name prefix | `netframework_clrmemory`
+|||
+-|-
+Metric name prefix  | `netframework_clrmemory`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRMemory`
 Enabled by default? | No
 

docs/collector.netframework_clrremoting.md

@@ -2,7 +2,9 @@
 
 The netframework_clrremoting collector exposes metrics about dotnet remoting.
 
-Metric name prefix | `netframework_clrremoting`
+|||
+-|-
+Metric name prefix  | `netframework_clrremoting`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRRemoting`
 Enabled by default? | No
 

docs/collector.netframework_clrsecurity.md

@@ -2,7 +2,9 @@
 
 The netframework_clrsecurity collector exposes metrics about security checks in dotnet applications
 
-Metric name prefix | `netframework_clrsecurity`
+|||
+-|-
+Metric name prefix  | `netframework_clrsecurity`
 Classes             | `Win32_PerfRawData_NETFramework_NETCLRSecurity`
 Enabled by default? | No
 

docs/collector.os.md

@@ -2,7 +2,9 @@
 
 The os collector exposes metrics about the operating system
 
-Metric name prefix | `os`
+|||
+-|-
+Metric name prefix  | `os`
 Classes             | [`Win32_OperatingSystem`](https://msdn.microsoft.com/en-us/library/aa394239)
 Enabled by default? | Yes
 

docs/collector.process.md

@@ -2,7 +2,9 @@
 
 The process collector exposes metrics about processes
 
-Metric name prefix | `process`
+|||
+-|-
+Metric name prefix  | `process`
 Classes             | [`Win32_PerfRawData_PerfProc_Process`](https://msdn.microsoft.com/en-us/library/aa394323(v=vs.85).aspx)
 Enabled by default? | No
 

docs/collector.service.md

@@ -2,7 +2,9 @@
 
 The service collector exposes metrics about Windows Services
 
-Metric name prefix | `service`
+|||
+-|-
+Metric name prefix  | `service`
 Classes             | [`Win32_Service`](https://msdn.microsoft.com/en-us/library/aa394418(v=vs.85).aspx)
 Enabled by default? | Yes
 
@@ -64,10 +66,42 @@ A service can have any of the following statuses:
 Note that there is some overlap with service state.
 
 ### Example metric
-_This collector does not yet have explained examples, we would appreciate your help adding them!_
+Lists the services that have a 'disabled' start mode.
+```
+wmi_service_start_mode{exported_name=~"(mssqlserver|sqlserveragent)",start_mode="disabled"}
+```
 
 ## Useful queries
-_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+Counts the number of Microsoft SQL Server/Agent Processes
+```
+count(wmi_service_state{exported_name=~"(sqlserveragent|mssqlserver)",state="running"})
+```
 
 ## Alerting examples
-_This collector does not yet have alerting examples, we would appreciate your help adding them!_
+**prometheus.rules**
+```
+groups:
+- name: Microsoft SQL Server Alerts
+  rules:
+
+  # Sends an alert when the 'sqlserveragent' service is not in the running state for 3 minutes. 
+  - alert: SQL Server Agent DOWN
+    expr: wmi_service_state{instance="SQL",exported_name="sqlserveragent",state="running"} == 0
+    for: 3m
+    labels:
+      severity: high
+    annotations:
+      summary: "Service {{ $labels.exported_name }} down"
+      description: "Service {{ $labels.exported_name }} on instance {{ $labels.instance }} has been down for more than 3 minutes."
+      
+  # Sends an alert when the 'mssqlserver' service is not in the running state for 3 minutes. 
+  - alert: SQL Server DOWN
+    expr: wmi_service_state{instance="SQL",exported_name="mssqlserver",state="running"} == 0
+    for: 3m
+    labels:
+      severity: high
+    annotations:
+      summary: "Service {{ $labels.exported_name }} down"
+      description: "Service {{ $labels.exported_name }} on instance {{ $labels.instance }} has been down for more than 3 minutes."
+```
+In this example, `instance` is the target label of the host. So each alert will be processed per host, which is then used in the alert description.

docs/collector.system.md

@@ -2,7 +2,9 @@
 
 The system collector exposes metrics about ...
 
-Metric name prefix | `system`
+|||
+-|-
+Metric name prefix  | `system`
 Classes             | [`Win32_PerfRawData_PerfOS_System`](https://web.archive.org/web/20050830140516/http://msdn.microsoft.com/library/en-us/wmisdk/wmi/win32_perfrawdata_perfos_system.asp)
 Enabled by default? | Yes
 

docs/collector.tcp.md

@@ -2,7 +2,9 @@
 
 The tcp collector exposes metrics about the TCP/IPv4 network stack.
 
-Metric name prefix | `tcp`
+|||
+-|-
+Metric name prefix  | `tcp`
 Classes             | [`Win32_PerfRawData_Tcpip_TCPv4`](https://msdn.microsoft.com/en-us/library/aa394341(v=vs.85).aspx)
 Enabled by default? | No
 

docs/collector.textfile.md

@@ -2,7 +2,9 @@
 
 The textfile collector exposes metrics from files written by other processes.
 
-Metric name prefix | `textfile`
+|||
+-|-
+Metric name prefix  | `textfile`
 Classes             | None
 Enabled by default? | Yes
 
@@ -10,7 +12,7 @@ Enabled by default? | Yes
 
 ### `--collector.textfile.directory`
 
-The directory containing the files to be ingested.
+The directory containing the files to be ingested. Only files with the extension `.prom` are read.
 
 Default value: `C:\Program Files\wmi_exporter\textfile_inputs`
 
@@ -34,3 +36,21 @@ _This collector does not yet have any useful queries added, we would appreciate
 
 ## Alerting examples
 _This collector does not yet have alerting examples, we would appreciate your help adding them!_
+
+# Example use
+This Powershell script, when run in the `collector.textfile.directory` (default `C:\Program Files\wmi_exporter\textfile_inputs`), generates a valid `.prom` file that should successfully ingested by wmi_exporter.
+
+```Powershell
+$alpha = 42
+$beta = @{ left=3.1415; right=2.718281828; }
+
+Set-Content -Path test1.prom -Encoding Ascii -NoNewline -Value ""
+Add-Content -Path test1.prom -Encoding Ascii -NoNewline -Value "# HELP test_alpha_total Some random metric.`n"
+Add-Content -Path test1.prom -Encoding Ascii -NoNewline -Value "# TYPE test_alpha_total counter`n"
+Add-Content -Path test1.prom -Encoding Ascii -NoNewline -Value "test_alpha_total ${alpha}`n"
+Add-Content -Path test1.prom -Encoding Ascii -NoNewline -Value "# HELP test_beta_bytes Some other metric.`n"
+Add-Content -Path test1.prom -Encoding Ascii -NoNewline -Value "# TYPE test_beta_bytes gauge`n"
+foreach ($k in $beta.Keys) {
+  Add-Content -Path test1.prom -Encoding Ascii -NoNewline -Value "test_beta_bytes{spin=""${k}""} $( $beta[$k] )`n"
+}
+```

docs/collector.thermalzone.md

@@ -0,0 +1,32 @@
+# thermalzone collector
+
+The thermalzone collector exposes metrics about system temps. Note that temperature is given in Kelvin
+
+|||
+-|-
+Metric name prefix  | `thermalzone`
+Classes             | [`Win32_PerfRawData_Counters_ThermalZoneInformation`](https://wutils.com/wmi/root/cimv2/win32_perfrawdata_counters_thermalzoneinformation/#temperature_properties)
+Enabled by default? | No
+
+## Flags
+
+None
+
+## Metrics
+
+Name | Description | Type | Labels
+-----|-------------|------|-------
+`wmi_thermalzone_percent_passive_limit` | % Passive Limit is the current limit this thermal zone is placing on the devices it controls. A limit of 100% indicates the devices are unconstrained. A limit of 0% indicates the devices are fully constrained. | gauge | None
+`wmi_thermalzone_temperature_celsius ` | Temperature of the thermal zone, in degrees Celsius. | gauge | None
+`wmi_thermalzone_throttle_reasons ` | Throttle Reasons indicate reasons why the thermal zone is limiting performance of the devices it controls. 0x0 – The zone is not throttled. 0x1 – The zone is throttled for thermal reasons. 0x2 – The zone is throttled to limit electrical current. | gauge | None
+
+[`Throttle reasons` source](https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/examples--requirements-and-diagnostics)
+
+### Example metric
+_This collector does not yet have explained examples, we would appreciate your help adding them!_
+
+## Useful queries
+_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+
+## Alerting examples
+_This collector does not yet have alerting examples, we would appreciate your help adding them!_

docs/collector.vmware.md

@@ -2,7 +2,9 @@
 
 The vmware collector exposes metrics about a VMware guest VM
 
-Metric name prefix | `vmware`
+|||
+-|-
+Metric name prefix  | `vmware`
 Classes             | `Win32_PerfRawData_vmGuestLib_VMem`, `Win32_PerfRawData_vmGuestLib_VCPU`
 Enabled by default? | No
 

exporter.go

@@ -1,10 +1,13 @@
+// +build windows
+
 package main
 
 import (
 	"fmt"
-	"io"
 	"net/http"
+	"os"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -22,7 +25,8 @@ import (
 
 // WmiCollector implements the prometheus.Collector interface.
 type WmiCollector struct {
-	collectors map[string]collector.Collector
+	maxScrapeDuration time.Duration
+	collectors        map[string]collector.Collector
 }
 
 const (
@@ -44,6 +48,18 @@ var (
 		[]string{"collector"},
 		nil,
 	)
+	scrapeTimeoutDesc = prometheus.NewDesc(
+		prometheus.BuildFQName(collector.Namespace, "exporter", "collector_timeout"),
+		"wmi_exporter: Whether the collector timed out.",
+		[]string{"collector"},
+		nil,
+	)
+	snapshotDuration = prometheus.NewDesc(
+		prometheus.BuildFQName(collector.Namespace, "exporter", "perflib_snapshot_duration_seconds"),
+		"Duration of perflib snapshot capture",
+		nil,
+		nil,
+	)
 
 	// This can be removed when client_golang exposes this on Windows
 	// (See https://github.com/prometheus/client_golang/issues/376)
@@ -63,25 +79,112 @@ func (coll WmiCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- scrapeSuccessDesc
 }
 
-// Collect sends the collected metrics from each of the collectors to
-// prometheus. Collect could be called several times concurrently
-// and thus its run is protected by a single mutex.
-func (coll WmiCollector) Collect(ch chan<- prometheus.Metric) {
-	wg := sync.WaitGroup{}
-	wg.Add(len(coll.collectors))
-	for name, c := range coll.collectors {
-		go func(name string, c collector.Collector) {
-			execute(name, c, ch)
-			wg.Done()
-		}(name, c)
-	}
+type collectorOutcome int
 
+const (
+	pending collectorOutcome = iota
+	success
+	failed
+)
+
+// Collect sends the collected metrics from each of the collectors to
+// prometheus.
+func (coll WmiCollector) Collect(ch chan<- prometheus.Metric) {
 	ch <- prometheus.MustNewConstMetric(
 		startTimeDesc,
 		prometheus.CounterValue,
 		startTime,
 	)
-	wg.Wait()
+
+	t := time.Now()
+	scrapeContext, err := collector.PrepareScrapeContext()
+	ch <- prometheus.MustNewConstMetric(
+		snapshotDuration,
+		prometheus.GaugeValue,
+		time.Since(t).Seconds(),
+	)
+	if err != nil {
+		ch <- prometheus.NewInvalidMetric(scrapeSuccessDesc, fmt.Errorf("failed to prepare scrape: %v", err))
+		return
+	}
+
+	wg := sync.WaitGroup{}
+	wg.Add(len(coll.collectors))
+	collectorOutcomes := make(map[string]collectorOutcome)
+	for name := range coll.collectors {
+		collectorOutcomes[name] = pending
+	}
+
+	metricsBuffer := make(chan prometheus.Metric)
+	l := sync.Mutex{}
+	finished := false
+	go func() {
+		for m := range metricsBuffer {
+			l.Lock()
+			if !finished {
+				ch <- m
+			}
+			l.Unlock()
+		}
+	}()
+
+	for name, c := range coll.collectors {
+		go func(name string, c collector.Collector) {
+			defer wg.Done()
+			outcome := execute(name, c, scrapeContext, metricsBuffer)
+			l.Lock()
+			if !finished {
+				collectorOutcomes[name] = outcome
+			}
+			l.Unlock()
+		}(name, c)
+	}
+
+	allDone := make(chan struct{})
+	go func() {
+		wg.Wait()
+		close(allDone)
+	}()
+
+	// Wait until either all collectors finish, or timeout expires
+	select {
+	case <-allDone:
+	case <-time.After(coll.maxScrapeDuration):
+	}
+
+	l.Lock()
+	finished = true
+
+	remainingCollectorNames := make([]string, 0)
+	for name, outcome := range collectorOutcomes {
+		var successValue, timeoutValue float64
+		if outcome == pending {
+			timeoutValue = 1.0
+			remainingCollectorNames = append(remainingCollectorNames, name)
+		}
+		if outcome == success {
+			successValue = 1.0
+		}
+
+		ch <- prometheus.MustNewConstMetric(
+			scrapeSuccessDesc,
+			prometheus.GaugeValue,
+			successValue,
+			name,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			scrapeTimeoutDesc,
+			prometheus.GaugeValue,
+			timeoutValue,
+			name,
+		)
+	}
+
+	if len(remainingCollectorNames) > 0 {
+		log.Warn("Collection timed out, still waiting for ", remainingCollectorNames)
+	}
+
+	l.Unlock()
 }
 
 func filterAvailableCollectors(collectors string) string {
@@ -95,31 +198,23 @@ func filterAvailableCollectors(collectors string) string {
 	return strings.Join(availableCollectors, ",")
 }
 
-func execute(name string, c collector.Collector, ch chan<- prometheus.Metric) {
-	begin := time.Now()
-	err := c.Collect(ch)
-	duration := time.Since(begin)
-	var success float64
-
-	if err != nil {
-		log.Errorf("collector %s failed after %fs: %s", name, duration.Seconds(), err)
-		success = 0
-	} else {
-		log.Debugf("collector %s succeeded after %fs.", name, duration.Seconds())
-		success = 1
-	}
+func execute(name string, c collector.Collector, ctx *collector.ScrapeContext, ch chan<- prometheus.Metric) collectorOutcome {
+	t := time.Now()
+	err := c.Collect(ctx, ch)
+	duration := time.Since(t).Seconds()
 	ch <- prometheus.MustNewConstMetric(
 		scrapeDurationDesc,
 		prometheus.GaugeValue,
-		duration.Seconds(),
-		name,
-	)
-	ch <- prometheus.MustNewConstMetric(
-		scrapeSuccessDesc,
-		prometheus.GaugeValue,
-		success,
+		duration,
 		name,
 	)
+
+	if err != nil {
+		log.Errorf("collector %s failed after %fs: %s", name, duration, err)
+		return failed
+	}
+	log.Debugf("collector %s succeeded after %fs.", name, duration)
+	return success
 }
 
 func expandEnabledCollectors(enabled string) []string {
@@ -156,10 +251,6 @@ func loadCollectors(list string) (map[string]collector.Collector, error) {
 	return collectors, nil
 }
 
-func init() {
-	prometheus.MustRegister(version.NewCollector("wmi_exporter"))
-}
-
 func initWbem() {
 	// This initialization prevents a memory leak on WMF 5+. See
 	// https://github.com/martinlindhe/wmi_exporter/issues/77 and linked issues
@@ -191,6 +282,10 @@ func main() {
 			"collectors.print",
 			"If true, print available collectors and exit.",
 		).Bool()
+		timeoutMargin = kingpin.Flag(
+			"scrape.timeout-margin",
+			"Seconds to subtract from the timeout allowed by the client. Tune to allow for overhead or high loads.",
+		).Default("0.5").Float64()
 	)
 
 	log.AddFlags(kingpin.CommandLine)
@@ -220,7 +315,12 @@ func main() {
 
 	stopCh := make(chan bool)
 	if !isInteractive {
-		go svc.Run(serviceName, &wmiExporterService{stopCh: stopCh})
+		go func() {
+			err = svc.Run(serviceName, &wmiExporterService{stopCh: stopCh})
+			if err != nil {
+				log.Errorf("Failed to start service: %v", err)
+			}
+		}()
 	}
 
 	collectors, err := loadCollectors(*enabledCollectors)
@@ -230,10 +330,17 @@ func main() {
 
 	log.Infof("Enabled collectors: %v", strings.Join(keys(collectors), ", "))
 
-	nodeCollector := WmiCollector{collectors: collectors}
-	prometheus.MustRegister(nodeCollector)
+	h := &metricsHandler{
+		timeoutMargin: *timeoutMargin,
+		collectorFactory: func(timeout time.Duration) *WmiCollector {
+			return &WmiCollector{
+				collectors:        collectors,
+				maxScrapeDuration: timeout,
+			}
+		},
+	}
 
-	http.Handle(*metricsPath, promhttp.Handler())
+	http.Handle(*metricsPath, h)
 	http.HandleFunc("/health", healthCheck)
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		http.Redirect(w, r, *metricsPath, http.StatusMovedPermanently)
@@ -257,7 +364,10 @@ func main() {
 
 func healthCheck(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
-	io.WriteString(w, `{"status":"ok"}`)
+	_, err := fmt.Fprintln(w, `{"status":"ok"}`)
+	if err != nil {
+		log.Debugf("Failed to write to stream: %v", err)
+	}
 }
 
 func keys(m map[string]collector.Collector) []string {
@@ -294,3 +404,36 @@ loop:
 	changes <- svc.Status{State: svc.StopPending}
 	return
 }
+
+type metricsHandler struct {
+	timeoutMargin    float64
+	collectorFactory func(timeout time.Duration) *WmiCollector
+}
+
+func (mh *metricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	const defaultTimeout = 10.0
+
+	var timeoutSeconds float64
+	if v := r.Header.Get("X-Prometheus-Scrape-Timeout-Seconds"); v != "" {
+		var err error
+		timeoutSeconds, err = strconv.ParseFloat(v, 64)
+		if err != nil {
+			log.Warnf("Couldn't parse X-Prometheus-Scrape-Timeout-Seconds: %q. Defaulting timeout to %f", v, defaultTimeout)
+		}
+	}
+	if timeoutSeconds == 0 {
+		timeoutSeconds = defaultTimeout
+	}
+	timeoutSeconds = timeoutSeconds - mh.timeoutMargin
+
+	reg := prometheus.NewRegistry()
+	reg.MustRegister(mh.collectorFactory(time.Duration(timeoutSeconds * float64(time.Second))))
+	reg.MustRegister(
+		prometheus.NewProcessCollector(os.Getpid(), ""),
+		prometheus.NewGoCollector(),
+		version.NewCollector("wmi_exporter"),
+	)
+
+	h := promhttp.HandlerFor(reg, promhttp.HandlerOpts{})
+	h.ServeHTTP(w, r)
+}

exporter_test.go

@@ -1,3 +1,5 @@
+// +build windows
+
 package main
 
 import (

gometalinter.config

@@ -0,0 +1,28 @@
+{
+    "Disable": [
+        "goconst",
+        "gocyclo",
+        "gosec",
+        "maligned",
+        "megacheck"
+    ],
+    "Enable": [
+        "deadcode",
+        "errcheck",
+        "golint",
+        "gotype",
+        "gotypex",
+        "ineffassign",
+        "interfacer",
+        "structcheck",
+        "unconvert",
+        "varcheck",
+        "vet",
+        "vetshadow"
+    ],
+    "Exclude": [
+        "don't use underscores in Go names",
+        "exported type .+ should have comment or be unexported",
+        "should be"
+    ]
+}

installer/wmi_exporter.wxs

@@ -19,6 +19,9 @@
     <Property Id="ENABLED_COLLECTORS" Secure="yes"/>
     <SetProperty Id="CollectorsFlag" After="InstallFiles" Sequence="execute" Value="--collectors.enabled [ENABLED_COLLECTORS]">ENABLED_COLLECTORS</SetProperty>
 
+    <Property Id="EXTRA_FLAGS" Secure="yes"/>
+    <SetProperty Id="ExtraFlags" After="InstallFiles" Sequence="execute" Value="[EXTRA_FLAGS]">EXTRA_FLAGS</SetProperty>
+
     <Property Id="LISTEN_ADDR" Secure="yes" />
     <Property Id="LISTEN_PORT" Secure="yes" Value="9182" />
     <SetProperty Id="ListenFlag" After="InstallFiles" Sequence="execute" Value="--telemetry.addr [LISTEN_ADDR]:[LISTEN_PORT]">LISTEN_ADDR OR LISTEN_PORT</SetProperty>
@@ -42,10 +45,11 @@
         <File Id="wmi_exporter.exe" Name="wmi_exporter.exe" Source="Work\wmi_exporter.exe" KeyPath="yes">
           <fw:FirewallException Id="MetricsEndpoint" Name="WMI Exporter (HTTP [LISTEN_PORT])" Description="WMI Exporter HTTP endpoint" Port="[LISTEN_PORT]" Protocol="tcp" Scope="any" IgnoreFailure="yes" />
         </File>
-        <ServiceInstall Id="InstallExporterService" Name="wmi_exporter" DisplayName="WMI exporter" Description="Exports Prometheus metrics from WMI queries" ErrorControl="normal" Start="auto" Type="ownProcess" Arguments="--log.format logger:eventlog?name=wmi_exporter [CollectorsFlag] [ListenFlag] [MetricsPathFlag] [TextfileDirFlag]">
+        <ServiceInstall Id="InstallExporterService" Name="wmi_exporter" DisplayName="WMI exporter" Description="Exports Prometheus metrics from WMI queries" ErrorControl="normal" Start="auto" Type="ownProcess" Arguments="--log.format logger:eventlog?name=wmi_exporter [CollectorsFlag] [ListenFlag] [MetricsPathFlag] [TextfileDirFlag] [ExtraFlags]">
           <util:ServiceConfig FirstFailureActionType="restart" SecondFailureActionType="restart" ThirdFailureActionType="restart" RestartServiceDelayInSeconds="5" />
         </ServiceInstall>
         <ServiceControl Id="ServiceStateControl" Name="wmi_exporter" Remove="uninstall" Start="install" Stop="both" />
+        <util:EventSource Log="Application" Name="wmi_exporter" EventMessageFile="%SystemRoot%\System32\EventCreate.exe" />
       </Component>
       <Component Id="CreateTextfileDirectory" Directory="textfile_inputs" Guid="d03ef58a-9cbf-4165-ad39-d143e9b27e14">
         <CreateFolder />

tools/collector-generator/New-Collector.ps1

@@ -20,7 +20,7 @@ else {
 $members = $wmiObject `
     | Get-Member -MemberType Properties `
     | Where-Object { $_.Definition -Match '^u?int' -and $_.Name -NotMatch '_' } `
-    | Select-Object Name, @{Name="Type";Expression={$_.Definition.Split(" ")[0]}}
+    | Select-Object Name, @{Name="Type";Expression={$_.Definition.Split(" ")[0]}})
 $input = @{
     "Class"=$Class;
     "CollectorName"=$CollectorName;

tools/collector-generator/collector.template

@@ -1,5 +1,3 @@
-// returns data points from {{ .Class }}
-// <add link to documentation here> - {{ .Class }} class
 package collector
 import (
     "github.com/StackExchange/wmi"
@@ -31,13 +29,15 @@ func New{{ .CollectorName }}Collector() (Collector, error) {
 }
 // Collect sends the metric values for each metric
 // to the provided prometheus Metric channel.
-func (c *{{ .CollectorName }}Collector) Collect(ch chan<- prometheus.Metric) error {
+func (c *{{ .CollectorName }}Collector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
     if desc, err := c.collect(ch); err != nil {
         log.Error("failed collecting {{ .CollectorName | toLower }} metrics:", desc, err)
         return err
     }
     return nil
 }
+// {{ .Class }} docs:
+// - <add link to documentation here>
 type {{ .Class }} struct {
     Name string
 {{ range $m := .Members }}

tools/collector-generator/generate-collector.go

@@ -25,7 +25,7 @@ func main() {
 		panic(err)
 	}
 	var data TemplateData
-	if err := json.Unmarshal(bytes, &data); err != nil {
+	if err = json.Unmarshal(bytes, &data); err != nil {
 		panic(err)
 	}
 
@@ -33,11 +33,11 @@ func main() {
 		"toLower":     strings.ToLower,
 		"toSnakeCase": toSnakeCase,
 	}
-	template, err := template.New("template").Funcs(funcs).ParseFiles("collector.template")
+	tmpl, err := template.New("template").Funcs(funcs).ParseFiles("collector.template")
 	if err != nil {
 		panic(err)
 	}
-	err = template.ExecuteTemplate(os.Stdout, "collector.template", data)
+	err = tmpl.ExecuteTemplate(os.Stdout, "collector.template", data)
 	if err != nil {
 		panic(err)
 	}

vendor/github.com/Microsoft/go-winio/.gitignore

@@ -0,0 +1 @@
+*.exe

vendor/github.com/Microsoft/go-winio/LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Microsoft
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

vendor/github.com/Microsoft/go-winio/README.md

@@ -0,0 +1,22 @@
+# go-winio
+
+This repository contains utilities for efficiently performing Win32 IO operations in
+Go. Currently, this is focused on accessing named pipes and other file handles, and
+for using named pipes as a net transport.
+
+This code relies on IO completion ports to avoid blocking IO on system threads, allowing Go
+to reuse the thread to schedule another goroutine. This limits support to Windows Vista and
+newer operating systems. This is similar to the implementation of network sockets in Go's net
+package.
+
+Please see the LICENSE file for licensing information.
+
+This project has adopted the [Microsoft Open Source Code of
+Conduct](https://opensource.microsoft.com/codeofconduct/). For more information
+see the [Code of Conduct
+FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact
+[opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional
+questions or comments.
+
+Thanks to natefinch for the inspiration for this library. See https://github.com/natefinch/npipe
+for another named pipe implementation.

vendor/github.com/Microsoft/go-winio/archive/tar/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/Microsoft/go-winio/archive/tar/common.go

@@ -0,0 +1,344 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package tar implements access to tar archives.
+// It aims to cover most of the variations, including those produced
+// by GNU and BSD tars.
+//
+// References:
+//   http://www.freebsd.org/cgi/man.cgi?query=tar&sektion=5
+//   http://www.gnu.org/software/tar/manual/html_node/Standard.html
+//   http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html
+package tar
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"path"
+	"time"
+)
+
+const (
+	blockSize = 512
+
+	// Types
+	TypeReg           = '0'    // regular file
+	TypeRegA          = '\x00' // regular file
+	TypeLink          = '1'    // hard link
+	TypeSymlink       = '2'    // symbolic link
+	TypeChar          = '3'    // character device node
+	TypeBlock         = '4'    // block device node
+	TypeDir           = '5'    // directory
+	TypeFifo          = '6'    // fifo node
+	TypeCont          = '7'    // reserved
+	TypeXHeader       = 'x'    // extended header
+	TypeXGlobalHeader = 'g'    // global extended header
+	TypeGNULongName   = 'L'    // Next file has a long name
+	TypeGNULongLink   = 'K'    // Next file symlinks to a file w/ a long name
+	TypeGNUSparse     = 'S'    // sparse file
+)
+
+// A Header represents a single header in a tar archive.
+// Some fields may not be populated.
+type Header struct {
+	Name         string    // name of header file entry
+	Mode         int64     // permission and mode bits
+	Uid          int       // user id of owner
+	Gid          int       // group id of owner
+	Size         int64     // length in bytes
+	ModTime      time.Time // modified time
+	Typeflag     byte      // type of header entry
+	Linkname     string    // target name of link
+	Uname        string    // user name of owner
+	Gname        string    // group name of owner
+	Devmajor     int64     // major number of character or block device
+	Devminor     int64     // minor number of character or block device
+	AccessTime   time.Time // access time
+	ChangeTime   time.Time // status change time
+	CreationTime time.Time // creation time
+	Xattrs       map[string]string
+	Winheaders   map[string]string
+}
+
+// File name constants from the tar spec.
+const (
+	fileNameSize       = 100 // Maximum number of bytes in a standard tar name.
+	fileNamePrefixSize = 155 // Maximum number of ustar extension bytes.
+)
+
+// FileInfo returns an os.FileInfo for the Header.
+func (h *Header) FileInfo() os.FileInfo {
+	return headerFileInfo{h}
+}
+
+// headerFileInfo implements os.FileInfo.
+type headerFileInfo struct {
+	h *Header
+}
+
+func (fi headerFileInfo) Size() int64        { return fi.h.Size }
+func (fi headerFileInfo) IsDir() bool        { return fi.Mode().IsDir() }
+func (fi headerFileInfo) ModTime() time.Time { return fi.h.ModTime }
+func (fi headerFileInfo) Sys() interface{}   { return fi.h }
+
+// Name returns the base name of the file.
+func (fi headerFileInfo) Name() string {
+	if fi.IsDir() {
+		return path.Base(path.Clean(fi.h.Name))
+	}
+	return path.Base(fi.h.Name)
+}
+
+// Mode returns the permission and mode bits for the headerFileInfo.
+func (fi headerFileInfo) Mode() (mode os.FileMode) {
+	// Set file permission bits.
+	mode = os.FileMode(fi.h.Mode).Perm()
+
+	// Set setuid, setgid and sticky bits.
+	if fi.h.Mode&c_ISUID != 0 {
+		// setuid
+		mode |= os.ModeSetuid
+	}
+	if fi.h.Mode&c_ISGID != 0 {
+		// setgid
+		mode |= os.ModeSetgid
+	}
+	if fi.h.Mode&c_ISVTX != 0 {
+		// sticky
+		mode |= os.ModeSticky
+	}
+
+	// Set file mode bits.
+	// clear perm, setuid, setgid and sticky bits.
+	m := os.FileMode(fi.h.Mode) &^ 07777
+	if m == c_ISDIR {
+		// directory
+		mode |= os.ModeDir
+	}
+	if m == c_ISFIFO {
+		// named pipe (FIFO)
+		mode |= os.ModeNamedPipe
+	}
+	if m == c_ISLNK {
+		// symbolic link
+		mode |= os.ModeSymlink
+	}
+	if m == c_ISBLK {
+		// device file
+		mode |= os.ModeDevice
+	}
+	if m == c_ISCHR {
+		// Unix character device
+		mode |= os.ModeDevice
+		mode |= os.ModeCharDevice
+	}
+	if m == c_ISSOCK {
+		// Unix domain socket
+		mode |= os.ModeSocket
+	}
+
+	switch fi.h.Typeflag {
+	case TypeSymlink:
+		// symbolic link
+		mode |= os.ModeSymlink
+	case TypeChar:
+		// character device node
+		mode |= os.ModeDevice
+		mode |= os.ModeCharDevice
+	case TypeBlock:
+		// block device node
+		mode |= os.ModeDevice
+	case TypeDir:
+		// directory
+		mode |= os.ModeDir
+	case TypeFifo:
+		// fifo node
+		mode |= os.ModeNamedPipe
+	}
+
+	return mode
+}
+
+// sysStat, if non-nil, populates h from system-dependent fields of fi.
+var sysStat func(fi os.FileInfo, h *Header) error
+
+// Mode constants from the tar spec.
+const (
+	c_ISUID  = 04000   // Set uid
+	c_ISGID  = 02000   // Set gid
+	c_ISVTX  = 01000   // Save text (sticky bit)
+	c_ISDIR  = 040000  // Directory
+	c_ISFIFO = 010000  // FIFO
+	c_ISREG  = 0100000 // Regular file
+	c_ISLNK  = 0120000 // Symbolic link
+	c_ISBLK  = 060000  // Block special file
+	c_ISCHR  = 020000  // Character special file
+	c_ISSOCK = 0140000 // Socket
+)
+
+// Keywords for the PAX Extended Header
+const (
+	paxAtime        = "atime"
+	paxCharset      = "charset"
+	paxComment      = "comment"
+	paxCtime        = "ctime" // please note that ctime is not a valid pax header.
+	paxCreationTime = "LIBARCHIVE.creationtime"
+	paxGid          = "gid"
+	paxGname        = "gname"
+	paxLinkpath     = "linkpath"
+	paxMtime        = "mtime"
+	paxPath         = "path"
+	paxSize         = "size"
+	paxUid          = "uid"
+	paxUname        = "uname"
+	paxXattr        = "SCHILY.xattr."
+	paxWindows      = "MSWINDOWS."
+	paxNone         = ""
+)
+
+// FileInfoHeader creates a partially-populated Header from fi.
+// If fi describes a symlink, FileInfoHeader records link as the link target.
+// If fi describes a directory, a slash is appended to the name.
+// Because os.FileInfo's Name method returns only the base name of
+// the file it describes, it may be necessary to modify the Name field
+// of the returned header to provide the full path name of the file.
+func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
+	if fi == nil {
+		return nil, errors.New("tar: FileInfo is nil")
+	}
+	fm := fi.Mode()
+	h := &Header{
+		Name:    fi.Name(),
+		ModTime: fi.ModTime(),
+		Mode:    int64(fm.Perm()), // or'd with c_IS* constants later
+	}
+	switch {
+	case fm.IsRegular():
+		h.Mode |= c_ISREG
+		h.Typeflag = TypeReg
+		h.Size = fi.Size()
+	case fi.IsDir():
+		h.Typeflag = TypeDir
+		h.Mode |= c_ISDIR
+		h.Name += "/"
+	case fm&os.ModeSymlink != 0:
+		h.Typeflag = TypeSymlink
+		h.Mode |= c_ISLNK
+		h.Linkname = link
+	case fm&os.ModeDevice != 0:
+		if fm&os.ModeCharDevice != 0 {
+			h.Mode |= c_ISCHR
+			h.Typeflag = TypeChar
+		} else {
+			h.Mode |= c_ISBLK
+			h.Typeflag = TypeBlock
+		}
+	case fm&os.ModeNamedPipe != 0:
+		h.Typeflag = TypeFifo
+		h.Mode |= c_ISFIFO
+	case fm&os.ModeSocket != 0:
+		h.Mode |= c_ISSOCK
+	default:
+		return nil, fmt.Errorf("archive/tar: unknown file mode %v", fm)
+	}
+	if fm&os.ModeSetuid != 0 {
+		h.Mode |= c_ISUID
+	}
+	if fm&os.ModeSetgid != 0 {
+		h.Mode |= c_ISGID
+	}
+	if fm&os.ModeSticky != 0 {
+		h.Mode |= c_ISVTX
+	}
+	// If possible, populate additional fields from OS-specific
+	// FileInfo fields.
+	if sys, ok := fi.Sys().(*Header); ok {
+		// This FileInfo came from a Header (not the OS). Use the
+		// original Header to populate all remaining fields.
+		h.Uid = sys.Uid
+		h.Gid = sys.Gid
+		h.Uname = sys.Uname
+		h.Gname = sys.Gname
+		h.AccessTime = sys.AccessTime
+		h.ChangeTime = sys.ChangeTime
+		if sys.Xattrs != nil {
+			h.Xattrs = make(map[string]string)
+			for k, v := range sys.Xattrs {
+				h.Xattrs[k] = v
+			}
+		}
+		if sys.Typeflag == TypeLink {
+			// hard link
+			h.Typeflag = TypeLink
+			h.Size = 0
+			h.Linkname = sys.Linkname
+		}
+	}
+	if sysStat != nil {
+		return h, sysStat(fi, h)
+	}
+	return h, nil
+}
+
+var zeroBlock = make([]byte, blockSize)
+
+// POSIX specifies a sum of the unsigned byte values, but the Sun tar uses signed byte values.
+// We compute and return both.
+func checksum(header []byte) (unsigned int64, signed int64) {
+	for i := 0; i < len(header); i++ {
+		if i == 148 {
+			// The chksum field (header[148:156]) is special: it should be treated as space bytes.
+			unsigned += ' ' * 8
+			signed += ' ' * 8
+			i += 7
+			continue
+		}
+		unsigned += int64(header[i])
+		signed += int64(int8(header[i]))
+	}
+	return
+}
+
+type slicer []byte
+
+func (sp *slicer) next(n int) (b []byte) {
+	s := *sp
+	b, *sp = s[0:n], s[n:]
+	return
+}
+
+func isASCII(s string) bool {
+	for _, c := range s {
+		if c >= 0x80 {
+			return false
+		}
+	}
+	return true
+}
+
+func toASCII(s string) string {
+	if isASCII(s) {
+		return s
+	}
+	var buf bytes.Buffer
+	for _, c := range s {
+		if c < 0x80 {
+			buf.WriteByte(byte(c))
+		}
+	}
+	return buf.String()
+}
+
+// isHeaderOnlyType checks if the given type flag is of the type that has no
+// data section even if a size is specified.
+func isHeaderOnlyType(flag byte) bool {
+	switch flag {
+	case TypeLink, TypeSymlink, TypeChar, TypeBlock, TypeDir, TypeFifo:
+		return true
+	default:
+		return false
+	}
+}

vendor/github.com/Microsoft/go-winio/archive/tar/example_test.go

@@ -0,0 +1,80 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tar_test
+
+import (
+	"archive/tar"
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+func Example() {
+	// Create a buffer to write our archive to.
+	buf := new(bytes.Buffer)
+
+	// Create a new tar archive.
+	tw := tar.NewWriter(buf)
+
+	// Add some files to the archive.
+	var files = []struct {
+		Name, Body string
+	}{
+		{"readme.txt", "This archive contains some text files."},
+		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
+		{"todo.txt", "Get animal handling license."},
+	}
+	for _, file := range files {
+		hdr := &tar.Header{
+			Name: file.Name,
+			Mode: 0600,
+			Size: int64(len(file.Body)),
+		}
+		if err := tw.WriteHeader(hdr); err != nil {
+			log.Fatalln(err)
+		}
+		if _, err := tw.Write([]byte(file.Body)); err != nil {
+			log.Fatalln(err)
+		}
+	}
+	// Make sure to check the error on Close.
+	if err := tw.Close(); err != nil {
+		log.Fatalln(err)
+	}
+
+	// Open the tar archive for reading.
+	r := bytes.NewReader(buf.Bytes())
+	tr := tar.NewReader(r)
+
+	// Iterate through the files in the archive.
+	for {
+		hdr, err := tr.Next()
+		if err == io.EOF {
+			// end of tar archive
+			break
+		}
+		if err != nil {
+			log.Fatalln(err)
+		}
+		fmt.Printf("Contents of %s:\n", hdr.Name)
+		if _, err := io.Copy(os.Stdout, tr); err != nil {
+			log.Fatalln(err)
+		}
+		fmt.Println()
+	}
+
+	// Output:
+	// Contents of readme.txt:
+	// This archive contains some text files.
+	// Contents of gopher.txt:
+	// Gopher names:
+	// George
+	// Geoffrey
+	// Gonzo
+	// Contents of todo.txt:
+	// Get animal handling license.
+}

vendor/github.com/Microsoft/go-winio/archive/tar/stat_atim.go

@@ -0,0 +1,20 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux dragonfly openbsd solaris
+
+package tar
+
+import (
+	"syscall"
+	"time"
+)
+
+func statAtime(st *syscall.Stat_t) time.Time {
+	return time.Unix(st.Atim.Unix())
+}
+
+func statCtime(st *syscall.Stat_t) time.Time {
+	return time.Unix(st.Ctim.Unix())
+}

vendor/github.com/Microsoft/go-winio/archive/tar/stat_atimespec.go

@@ -0,0 +1,20 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin freebsd netbsd
+
+package tar
+
+import (
+	"syscall"
+	"time"
+)
+
+func statAtime(st *syscall.Stat_t) time.Time {
+	return time.Unix(st.Atimespec.Unix())
+}
+
+func statCtime(st *syscall.Stat_t) time.Time {
+	return time.Unix(st.Ctimespec.Unix())
+}

vendor/github.com/Microsoft/go-winio/archive/tar/stat_unix.go

@@ -0,0 +1,32 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux darwin dragonfly freebsd openbsd netbsd solaris
+
+package tar
+
+import (
+	"os"
+	"syscall"
+)
+
+func init() {
+	sysStat = statUnix
+}
+
+func statUnix(fi os.FileInfo, h *Header) error {
+	sys, ok := fi.Sys().(*syscall.Stat_t)
+	if !ok {
+		return nil
+	}
+	h.Uid = int(sys.Uid)
+	h.Gid = int(sys.Gid)
+	// TODO(bradfitz): populate username & group.  os/user
+	// doesn't cache LookupId lookups, and lacks group
+	// lookup functions.
+	h.AccessTime = statAtime(sys)
+	h.ChangeTime = statCtime(sys)
+	// TODO(bradfitz): major/minor device numbers?
+	return nil
+}

vendor/github.com/Microsoft/go-winio/archive/tar/tar_test.go

@@ -0,0 +1,325 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tar
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestFileInfoHeader(t *testing.T) {
+	fi, err := os.Stat("testdata/small.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	h, err := FileInfoHeader(fi, "")
+	if err != nil {
+		t.Fatalf("FileInfoHeader: %v", err)
+	}
+	if g, e := h.Name, "small.txt"; g != e {
+		t.Errorf("Name = %q; want %q", g, e)
+	}
+	if g, e := h.Mode, int64(fi.Mode().Perm())|c_ISREG; g != e {
+		t.Errorf("Mode = %#o; want %#o", g, e)
+	}
+	if g, e := h.Size, int64(5); g != e {
+		t.Errorf("Size = %v; want %v", g, e)
+	}
+	if g, e := h.ModTime, fi.ModTime(); !g.Equal(e) {
+		t.Errorf("ModTime = %v; want %v", g, e)
+	}
+	// FileInfoHeader should error when passing nil FileInfo
+	if _, err := FileInfoHeader(nil, ""); err == nil {
+		t.Fatalf("Expected error when passing nil to FileInfoHeader")
+	}
+}
+
+func TestFileInfoHeaderDir(t *testing.T) {
+	fi, err := os.Stat("testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+	h, err := FileInfoHeader(fi, "")
+	if err != nil {
+		t.Fatalf("FileInfoHeader: %v", err)
+	}
+	if g, e := h.Name, "testdata/"; g != e {
+		t.Errorf("Name = %q; want %q", g, e)
+	}
+	// Ignoring c_ISGID for golang.org/issue/4867
+	if g, e := h.Mode&^c_ISGID, int64(fi.Mode().Perm())|c_ISDIR; g != e {
+		t.Errorf("Mode = %#o; want %#o", g, e)
+	}
+	if g, e := h.Size, int64(0); g != e {
+		t.Errorf("Size = %v; want %v", g, e)
+	}
+	if g, e := h.ModTime, fi.ModTime(); !g.Equal(e) {
+		t.Errorf("ModTime = %v; want %v", g, e)
+	}
+}
+
+func TestFileInfoHeaderSymlink(t *testing.T) {
+	h, err := FileInfoHeader(symlink{}, "some-target")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if g, e := h.Name, "some-symlink"; g != e {
+		t.Errorf("Name = %q; want %q", g, e)
+	}
+	if g, e := h.Linkname, "some-target"; g != e {
+		t.Errorf("Linkname = %q; want %q", g, e)
+	}
+}
+
+type symlink struct{}
+
+func (symlink) Name() string       { return "some-symlink" }
+func (symlink) Size() int64        { return 0 }
+func (symlink) Mode() os.FileMode  { return os.ModeSymlink }
+func (symlink) ModTime() time.Time { return time.Time{} }
+func (symlink) IsDir() bool        { return false }
+func (symlink) Sys() interface{}   { return nil }
+
+func TestRoundTrip(t *testing.T) {
+	data := []byte("some file contents")
+
+	var b bytes.Buffer
+	tw := NewWriter(&b)
+	hdr := &Header{
+		Name:    "file.txt",
+		Uid:     1 << 21, // too big for 8 octal digits
+		Size:    int64(len(data)),
+		ModTime: time.Now(),
+	}
+	// tar only supports second precision.
+	hdr.ModTime = hdr.ModTime.Add(-time.Duration(hdr.ModTime.Nanosecond()) * time.Nanosecond)
+	if err := tw.WriteHeader(hdr); err != nil {
+		t.Fatalf("tw.WriteHeader: %v", err)
+	}
+	if _, err := tw.Write(data); err != nil {
+		t.Fatalf("tw.Write: %v", err)
+	}
+	if err := tw.Close(); err != nil {
+		t.Fatalf("tw.Close: %v", err)
+	}
+
+	// Read it back.
+	tr := NewReader(&b)
+	rHdr, err := tr.Next()
+	if err != nil {
+		t.Fatalf("tr.Next: %v", err)
+	}
+	if !reflect.DeepEqual(rHdr, hdr) {
+		t.Errorf("Header mismatch.\n got %+v\nwant %+v", rHdr, hdr)
+	}
+	rData, err := ioutil.ReadAll(tr)
+	if err != nil {
+		t.Fatalf("Read: %v", err)
+	}
+	if !bytes.Equal(rData, data) {
+		t.Errorf("Data mismatch.\n got %q\nwant %q", rData, data)
+	}
+}
+
+type headerRoundTripTest struct {
+	h  *Header
+	fm os.FileMode
+}
+
+func TestHeaderRoundTrip(t *testing.T) {
+	golden := []headerRoundTripTest{
+		// regular file.
+		{
+			h: &Header{
+				Name:     "test.txt",
+				Mode:     0644 | c_ISREG,
+				Size:     12,
+				ModTime:  time.Unix(1360600916, 0),
+				Typeflag: TypeReg,
+			},
+			fm: 0644,
+		},
+		// symbolic link.
+		{
+			h: &Header{
+				Name:     "link.txt",
+				Mode:     0777 | c_ISLNK,
+				Size:     0,
+				ModTime:  time.Unix(1360600852, 0),
+				Typeflag: TypeSymlink,
+			},
+			fm: 0777 | os.ModeSymlink,
+		},
+		// character device node.
+		{
+			h: &Header{
+				Name:     "dev/null",
+				Mode:     0666 | c_ISCHR,
+				Size:     0,
+				ModTime:  time.Unix(1360578951, 0),
+				Typeflag: TypeChar,
+			},
+			fm: 0666 | os.ModeDevice | os.ModeCharDevice,
+		},
+		// block device node.
+		{
+			h: &Header{
+				Name:     "dev/sda",
+				Mode:     0660 | c_ISBLK,
+				Size:     0,
+				ModTime:  time.Unix(1360578954, 0),
+				Typeflag: TypeBlock,
+			},
+			fm: 0660 | os.ModeDevice,
+		},
+		// directory.
+		{
+			h: &Header{
+				Name:     "dir/",
+				Mode:     0755 | c_ISDIR,
+				Size:     0,
+				ModTime:  time.Unix(1360601116, 0),
+				Typeflag: TypeDir,
+			},
+			fm: 0755 | os.ModeDir,
+		},
+		// fifo node.
+		{
+			h: &Header{
+				Name:     "dev/initctl",
+				Mode:     0600 | c_ISFIFO,
+				Size:     0,
+				ModTime:  time.Unix(1360578949, 0),
+				Typeflag: TypeFifo,
+			},
+			fm: 0600 | os.ModeNamedPipe,
+		},
+		// setuid.
+		{
+			h: &Header{
+				Name:     "bin/su",
+				Mode:     0755 | c_ISREG | c_ISUID,
+				Size:     23232,
+				ModTime:  time.Unix(1355405093, 0),
+				Typeflag: TypeReg,
+			},
+			fm: 0755 | os.ModeSetuid,
+		},
+		// setguid.
+		{
+			h: &Header{
+				Name:     "group.txt",
+				Mode:     0750 | c_ISREG | c_ISGID,
+				Size:     0,
+				ModTime:  time.Unix(1360602346, 0),
+				Typeflag: TypeReg,
+			},
+			fm: 0750 | os.ModeSetgid,
+		},
+		// sticky.
+		{
+			h: &Header{
+				Name:     "sticky.txt",
+				Mode:     0600 | c_ISREG | c_ISVTX,
+				Size:     7,
+				ModTime:  time.Unix(1360602540, 0),
+				Typeflag: TypeReg,
+			},
+			fm: 0600 | os.ModeSticky,
+		},
+		// hard link.
+		{
+			h: &Header{
+				Name:     "hard.txt",
+				Mode:     0644 | c_ISREG,
+				Size:     0,
+				Linkname: "file.txt",
+				ModTime:  time.Unix(1360600916, 0),
+				Typeflag: TypeLink,
+			},
+			fm: 0644,
+		},
+		// More information.
+		{
+			h: &Header{
+				Name:     "info.txt",
+				Mode:     0600 | c_ISREG,
+				Size:     0,
+				Uid:      1000,
+				Gid:      1000,
+				ModTime:  time.Unix(1360602540, 0),
+				Uname:    "slartibartfast",
+				Gname:    "users",
+				Typeflag: TypeReg,
+			},
+			fm: 0600,
+		},
+	}
+
+	for i, g := range golden {
+		fi := g.h.FileInfo()
+		h2, err := FileInfoHeader(fi, "")
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if strings.Contains(fi.Name(), "/") {
+			t.Errorf("FileInfo of %q contains slash: %q", g.h.Name, fi.Name())
+		}
+		name := path.Base(g.h.Name)
+		if fi.IsDir() {
+			name += "/"
+		}
+		if got, want := h2.Name, name; got != want {
+			t.Errorf("i=%d: Name: got %v, want %v", i, got, want)
+		}
+		if got, want := h2.Size, g.h.Size; got != want {
+			t.Errorf("i=%d: Size: got %v, want %v", i, got, want)
+		}
+		if got, want := h2.Uid, g.h.Uid; got != want {
+			t.Errorf("i=%d: Uid: got %d, want %d", i, got, want)
+		}
+		if got, want := h2.Gid, g.h.Gid; got != want {
+			t.Errorf("i=%d: Gid: got %d, want %d", i, got, want)
+		}
+		if got, want := h2.Uname, g.h.Uname; got != want {
+			t.Errorf("i=%d: Uname: got %q, want %q", i, got, want)
+		}
+		if got, want := h2.Gname, g.h.Gname; got != want {
+			t.Errorf("i=%d: Gname: got %q, want %q", i, got, want)
+		}
+		if got, want := h2.Linkname, g.h.Linkname; got != want {
+			t.Errorf("i=%d: Linkname: got %v, want %v", i, got, want)
+		}
+		if got, want := h2.Typeflag, g.h.Typeflag; got != want {
+			t.Logf("%#v %#v", g.h, fi.Sys())
+			t.Errorf("i=%d: Typeflag: got %q, want %q", i, got, want)
+		}
+		if got, want := h2.Mode, g.h.Mode; got != want {
+			t.Errorf("i=%d: Mode: got %o, want %o", i, got, want)
+		}
+		if got, want := fi.Mode(), g.fm; got != want {
+			t.Errorf("i=%d: fi.Mode: got %o, want %o", i, got, want)
+		}
+		if got, want := h2.AccessTime, g.h.AccessTime; got != want {
+			t.Errorf("i=%d: AccessTime: got %v, want %v", i, got, want)
+		}
+		if got, want := h2.ChangeTime, g.h.ChangeTime; got != want {
+			t.Errorf("i=%d: ChangeTime: got %v, want %v", i, got, want)
+		}
+		if got, want := h2.ModTime, g.h.ModTime; got != want {
+			t.Errorf("i=%d: ModTime: got %v, want %v", i, got, want)
+		}
+		if sysh, ok := fi.Sys().(*Header); !ok || sysh != g.h {
+			t.Errorf("i=%d: Sys didn't return original *Header", i)
+		}
+	}
+}

vendor/github.com/Microsoft/go-winio/archive/tar/writer.go

@@ -0,0 +1,444 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tar
+
+// TODO(dsymonds):
+// - catch more errors (no first header, etc.)
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var (
+	ErrWriteTooLong    = errors.New("archive/tar: write too long")
+	ErrFieldTooLong    = errors.New("archive/tar: header field too long")
+	ErrWriteAfterClose = errors.New("archive/tar: write after close")
+	errInvalidHeader   = errors.New("archive/tar: header field too long or contains invalid values")
+)
+
+// A Writer provides sequential writing of a tar archive in POSIX.1 format.
+// A tar archive consists of a sequence of files.
+// Call WriteHeader to begin a new file, and then call Write to supply that file's data,
+// writing at most hdr.Size bytes in total.
+type Writer struct {
+	w          io.Writer
+	err        error
+	nb         int64 // number of unwritten bytes for current file entry
+	pad        int64 // amount of padding to write after current file entry
+	closed     bool
+	usedBinary bool            // whether the binary numeric field extension was used
+	preferPax  bool            // use pax header instead of binary numeric header
+	hdrBuff    [blockSize]byte // buffer to use in writeHeader when writing a regular header
+	paxHdrBuff [blockSize]byte // buffer to use in writeHeader when writing a pax header
+}
+
+type formatter struct {
+	err error // Last error seen
+}
+
+// NewWriter creates a new Writer writing to w.
+func NewWriter(w io.Writer) *Writer { return &Writer{w: w, preferPax: true} }
+
+// Flush finishes writing the current file (optional).
+func (tw *Writer) Flush() error {
+	if tw.nb > 0 {
+		tw.err = fmt.Errorf("archive/tar: missed writing %d bytes", tw.nb)
+		return tw.err
+	}
+
+	n := tw.nb + tw.pad
+	for n > 0 && tw.err == nil {
+		nr := n
+		if nr > blockSize {
+			nr = blockSize
+		}
+		var nw int
+		nw, tw.err = tw.w.Write(zeroBlock[0:nr])
+		n -= int64(nw)
+	}
+	tw.nb = 0
+	tw.pad = 0
+	return tw.err
+}
+
+// Write s into b, terminating it with a NUL if there is room.
+func (f *formatter) formatString(b []byte, s string) {
+	if len(s) > len(b) {
+		f.err = ErrFieldTooLong
+		return
+	}
+	ascii := toASCII(s)
+	copy(b, ascii)
+	if len(ascii) < len(b) {
+		b[len(ascii)] = 0
+	}
+}
+
+// Encode x as an octal ASCII string and write it into b with leading zeros.
+func (f *formatter) formatOctal(b []byte, x int64) {
+	s := strconv.FormatInt(x, 8)
+	// leading zeros, but leave room for a NUL.
+	for len(s)+1 < len(b) {
+		s = "0" + s
+	}
+	f.formatString(b, s)
+}
+
+// fitsInBase256 reports whether x can be encoded into n bytes using base-256
+// encoding. Unlike octal encoding, base-256 encoding does not require that the
+// string ends with a NUL character. Thus, all n bytes are available for output.
+//
+// If operating in binary mode, this assumes strict GNU binary mode; which means
+// that the first byte can only be either 0x80 or 0xff. Thus, the first byte is
+// equivalent to the sign bit in two's complement form.
+func fitsInBase256(n int, x int64) bool {
+	var binBits = uint(n-1) * 8
+	return n >= 9 || (x >= -1<<binBits && x < 1<<binBits)
+}
+
+// Write x into b, as binary (GNUtar/star extension).
+func (f *formatter) formatNumeric(b []byte, x int64) {
+	if fitsInBase256(len(b), x) {
+		for i := len(b) - 1; i >= 0; i-- {
+			b[i] = byte(x)
+			x >>= 8
+		}
+		b[0] |= 0x80 // Highest bit indicates binary format
+		return
+	}
+
+	f.formatOctal(b, 0) // Last resort, just write zero
+	f.err = ErrFieldTooLong
+}
+
+var (
+	minTime = time.Unix(0, 0)
+	// There is room for 11 octal digits (33 bits) of mtime.
+	maxTime = minTime.Add((1<<33 - 1) * time.Second)
+)
+
+// WriteHeader writes hdr and prepares to accept the file's contents.
+// WriteHeader calls Flush if it is not the first header.
+// Calling after a Close will return ErrWriteAfterClose.
+func (tw *Writer) WriteHeader(hdr *Header) error {
+	return tw.writeHeader(hdr, true)
+}
+
+// WriteHeader writes hdr and prepares to accept the file's contents.
+// WriteHeader calls Flush if it is not the first header.
+// Calling after a Close will return ErrWriteAfterClose.
+// As this method is called internally by writePax header to allow it to
+// suppress writing the pax header.
+func (tw *Writer) writeHeader(hdr *Header, allowPax bool) error {
+	if tw.closed {
+		return ErrWriteAfterClose
+	}
+	if tw.err == nil {
+		tw.Flush()
+	}
+	if tw.err != nil {
+		return tw.err
+	}
+
+	// a map to hold pax header records, if any are needed
+	paxHeaders := make(map[string]string)
+
+	// TODO(shanemhansen): we might want to use PAX headers for
+	// subsecond time resolution, but for now let's just capture
+	// too long fields or non ascii characters
+
+	var f formatter
+	var header []byte
+
+	// We need to select which scratch buffer to use carefully,
+	// since this method is called recursively to write PAX headers.
+	// If allowPax is true, this is the non-recursive call, and we will use hdrBuff.
+	// If allowPax is false, we are being called by writePAXHeader, and hdrBuff is
+	// already being used by the non-recursive call, so we must use paxHdrBuff.
+	header = tw.hdrBuff[:]
+	if !allowPax {
+		header = tw.paxHdrBuff[:]
+	}
+	copy(header, zeroBlock)
+	s := slicer(header)
+
+	// Wrappers around formatter that automatically sets paxHeaders if the
+	// argument extends beyond the capacity of the input byte slice.
+	var formatString = func(b []byte, s string, paxKeyword string) {
+		needsPaxHeader := paxKeyword != paxNone && len(s) > len(b) || !isASCII(s)
+		if needsPaxHeader {
+			paxHeaders[paxKeyword] = s
+			return
+		}
+		f.formatString(b, s)
+	}
+	var formatNumeric = func(b []byte, x int64, paxKeyword string) {
+		// Try octal first.
+		s := strconv.FormatInt(x, 8)
+		if len(s) < len(b) {
+			f.formatOctal(b, x)
+			return
+		}
+
+		// If it is too long for octal, and PAX is preferred, use a PAX header.
+		if paxKeyword != paxNone && tw.preferPax {
+			f.formatOctal(b, 0)
+			s := strconv.FormatInt(x, 10)
+			paxHeaders[paxKeyword] = s
+			return
+		}
+
+		tw.usedBinary = true
+		f.formatNumeric(b, x)
+	}
+	var formatTime = func(b []byte, t time.Time, paxKeyword string) {
+		var unixTime int64
+		if !t.Before(minTime) && !t.After(maxTime) {
+			unixTime = t.Unix()
+		}
+		formatNumeric(b, unixTime, paxNone)
+
+		// Write a PAX header if the time didn't fit precisely.
+		if paxKeyword != "" && tw.preferPax && allowPax && (t.Nanosecond() != 0 || !t.Before(minTime) || !t.After(maxTime)) {
+			paxHeaders[paxKeyword] = formatPAXTime(t)
+		}
+	}
+
+	// keep a reference to the filename to allow to overwrite it later if we detect that we can use ustar longnames instead of pax
+	pathHeaderBytes := s.next(fileNameSize)
+
+	formatString(pathHeaderBytes, hdr.Name, paxPath)
+
+	f.formatOctal(s.next(8), hdr.Mode)               // 100:108
+	formatNumeric(s.next(8), int64(hdr.Uid), paxUid) // 108:116
+	formatNumeric(s.next(8), int64(hdr.Gid), paxGid) // 116:124
+	formatNumeric(s.next(12), hdr.Size, paxSize)     // 124:136
+	formatTime(s.next(12), hdr.ModTime, paxMtime)    // 136:148
+	s.next(8)                                        // chksum (148:156)
+	s.next(1)[0] = hdr.Typeflag                      // 156:157
+
+	formatString(s.next(100), hdr.Linkname, paxLinkpath)
+
+	copy(s.next(8), []byte("ustar\x0000"))          // 257:265
+	formatString(s.next(32), hdr.Uname, paxUname)   // 265:297
+	formatString(s.next(32), hdr.Gname, paxGname)   // 297:329
+	formatNumeric(s.next(8), hdr.Devmajor, paxNone) // 329:337
+	formatNumeric(s.next(8), hdr.Devminor, paxNone) // 337:345
+
+	// keep a reference to the prefix to allow to overwrite it later if we detect that we can use ustar longnames instead of pax
+	prefixHeaderBytes := s.next(155)
+	formatString(prefixHeaderBytes, "", paxNone) // 345:500  prefix
+
+	// Use the GNU magic instead of POSIX magic if we used any GNU extensions.
+	if tw.usedBinary {
+		copy(header[257:265], []byte("ustar  \x00"))
+	}
+
+	_, paxPathUsed := paxHeaders[paxPath]
+	// try to use a ustar header when only the name is too long
+	if !tw.preferPax && len(paxHeaders) == 1 && paxPathUsed {
+		prefix, suffix, ok := splitUSTARPath(hdr.Name)
+		if ok {
+			// Since we can encode in USTAR format, disable PAX header.
+			delete(paxHeaders, paxPath)
+
+			// Update the path fields
+			formatString(pathHeaderBytes, suffix, paxNone)
+			formatString(prefixHeaderBytes, prefix, paxNone)
+		}
+	}
+
+	// The chksum field is terminated by a NUL and a space.
+	// This is different from the other octal fields.
+	chksum, _ := checksum(header)
+	f.formatOctal(header[148:155], chksum) // Never fails
+	header[155] = ' '
+
+	// Check if there were any formatting errors.
+	if f.err != nil {
+		tw.err = f.err
+		return tw.err
+	}
+
+	if allowPax {
+		if !hdr.AccessTime.IsZero() {
+			paxHeaders[paxAtime] = formatPAXTime(hdr.AccessTime)
+		}
+		if !hdr.ChangeTime.IsZero() {
+			paxHeaders[paxCtime] = formatPAXTime(hdr.ChangeTime)
+		}
+		if !hdr.CreationTime.IsZero() {
+			paxHeaders[paxCreationTime] = formatPAXTime(hdr.CreationTime)
+		}
+		for k, v := range hdr.Xattrs {
+			paxHeaders[paxXattr+k] = v
+		}
+		for k, v := range hdr.Winheaders {
+			paxHeaders[paxWindows+k] = v
+		}
+	}
+
+	if len(paxHeaders) > 0 {
+		if !allowPax {
+			return errInvalidHeader
+		}
+		if err := tw.writePAXHeader(hdr, paxHeaders); err != nil {
+			return err
+		}
+	}
+	tw.nb = int64(hdr.Size)
+	tw.pad = (blockSize - (tw.nb % blockSize)) % blockSize
+
+	_, tw.err = tw.w.Write(header)
+	return tw.err
+}
+
+func formatPAXTime(t time.Time) string {
+	sec := t.Unix()
+	usec := t.Nanosecond()
+	s := strconv.FormatInt(sec, 10)
+	if usec != 0 {
+		s = fmt.Sprintf("%s.%09d", s, usec)
+	}
+	return s
+}
+
+// splitUSTARPath splits a path according to USTAR prefix and suffix rules.
+// If the path is not splittable, then it will return ("", "", false).
+func splitUSTARPath(name string) (prefix, suffix string, ok bool) {
+	length := len(name)
+	if length <= fileNameSize || !isASCII(name) {
+		return "", "", false
+	} else if length > fileNamePrefixSize+1 {
+		length = fileNamePrefixSize + 1
+	} else if name[length-1] == '/' {
+		length--
+	}
+
+	i := strings.LastIndex(name[:length], "/")
+	nlen := len(name) - i - 1 // nlen is length of suffix
+	plen := i                 // plen is length of prefix
+	if i <= 0 || nlen > fileNameSize || nlen == 0 || plen > fileNamePrefixSize {
+		return "", "", false
+	}
+	return name[:i], name[i+1:], true
+}
+
+// writePaxHeader writes an extended pax header to the
+// archive.
+func (tw *Writer) writePAXHeader(hdr *Header, paxHeaders map[string]string) error {
+	// Prepare extended header
+	ext := new(Header)
+	ext.Typeflag = TypeXHeader
+	// Setting ModTime is required for reader parsing to
+	// succeed, and seems harmless enough.
+	ext.ModTime = hdr.ModTime
+	// The spec asks that we namespace our pseudo files
+	// with the current pid.  However, this results in differing outputs
+	// for identical inputs.  As such, the constant 0 is now used instead.
+	// golang.org/issue/12358
+	dir, file := path.Split(hdr.Name)
+	fullName := path.Join(dir, "PaxHeaders.0", file)
+
+	ascii := toASCII(fullName)
+	if len(ascii) > 100 {
+		ascii = ascii[:100]
+	}
+	ext.Name = ascii
+	// Construct the body
+	var buf bytes.Buffer
+
+	// Keys are sorted before writing to body to allow deterministic output.
+	var keys []string
+	for k := range paxHeaders {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	for _, k := range keys {
+		fmt.Fprint(&buf, formatPAXRecord(k, paxHeaders[k]))
+	}
+
+	ext.Size = int64(len(buf.Bytes()))
+	if err := tw.writeHeader(ext, false); err != nil {
+		return err
+	}
+	if _, err := tw.Write(buf.Bytes()); err != nil {
+		return err
+	}
+	if err := tw.Flush(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// formatPAXRecord formats a single PAX record, prefixing it with the
+// appropriate length.
+func formatPAXRecord(k, v string) string {
+	const padding = 3 // Extra padding for ' ', '=', and '\n'
+	size := len(k) + len(v) + padding
+	size += len(strconv.Itoa(size))
+	record := fmt.Sprintf("%d %s=%s\n", size, k, v)
+
+	// Final adjustment if adding size field increased the record size.
+	if len(record) != size {
+		size = len(record)
+		record = fmt.Sprintf("%d %s=%s\n", size, k, v)
+	}
+	return record
+}
+
+// Write writes to the current entry in the tar archive.
+// Write returns the error ErrWriteTooLong if more than
+// hdr.Size bytes are written after WriteHeader.
+func (tw *Writer) Write(b []byte) (n int, err error) {
+	if tw.closed {
+		err = ErrWriteAfterClose
+		return
+	}
+	overwrite := false
+	if int64(len(b)) > tw.nb {
+		b = b[0:tw.nb]
+		overwrite = true
+	}
+	n, err = tw.w.Write(b)
+	tw.nb -= int64(n)
+	if err == nil && overwrite {
+		err = ErrWriteTooLong
+		return
+	}
+	tw.err = err
+	return
+}
+
+// Close closes the tar archive, flushing any unwritten
+// data to the underlying writer.
+func (tw *Writer) Close() error {
+	if tw.err != nil || tw.closed {
+		return tw.err
+	}
+	tw.Flush()
+	tw.closed = true
+	if tw.err != nil {
+		return tw.err
+	}
+
+	// trailer: two zero blocks
+	for i := 0; i < 2; i++ {
+		_, tw.err = tw.w.Write(zeroBlock)
+		if tw.err != nil {
+			break
+		}
+	}
+	return tw.err
+}

vendor/github.com/Microsoft/go-winio/archive/tar/writer_test.go

@@ -0,0 +1,739 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tar
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math"
+	"os"
+	"reflect"
+	"sort"
+	"strings"
+	"testing"
+	"testing/iotest"
+	"time"
+)
+
+type writerTestEntry struct {
+	header   *Header
+	contents string
+}
+
+type writerTest struct {
+	file    string // filename of expected output
+	entries []*writerTestEntry
+}
+
+var writerTests = []*writerTest{
+	// The writer test file was produced with this command:
+	// tar (GNU tar) 1.26
+	//   ln -s small.txt link.txt
+	//   tar -b 1 --format=ustar -c -f writer.tar small.txt small2.txt link.txt
+	{
+		file: "testdata/writer.tar",
+		entries: []*writerTestEntry{
+			{
+				header: &Header{
+					Name:     "small.txt",
+					Mode:     0640,
+					Uid:      73025,
+					Gid:      5000,
+					Size:     5,
+					ModTime:  time.Unix(1246508266, 0),
+					Typeflag: '0',
+					Uname:    "dsymonds",
+					Gname:    "eng",
+				},
+				contents: "Kilts",
+			},
+			{
+				header: &Header{
+					Name:     "small2.txt",
+					Mode:     0640,
+					Uid:      73025,
+					Gid:      5000,
+					Size:     11,
+					ModTime:  time.Unix(1245217492, 0),
+					Typeflag: '0',
+					Uname:    "dsymonds",
+					Gname:    "eng",
+				},
+				contents: "Google.com\n",
+			},
+			{
+				header: &Header{
+					Name:     "link.txt",
+					Mode:     0777,
+					Uid:      1000,
+					Gid:      1000,
+					Size:     0,
+					ModTime:  time.Unix(1314603082, 0),
+					Typeflag: '2',
+					Linkname: "small.txt",
+					Uname:    "strings",
+					Gname:    "strings",
+				},
+				// no contents
+			},
+		},
+	},
+	// The truncated test file was produced using these commands:
+	//   dd if=/dev/zero bs=1048576 count=16384 > /tmp/16gig.txt
+	//   tar -b 1 -c -f- /tmp/16gig.txt | dd bs=512 count=8 > writer-big.tar
+	{
+		file: "testdata/writer-big.tar",
+		entries: []*writerTestEntry{
+			{
+				header: &Header{
+					Name:     "tmp/16gig.txt",
+					Mode:     0640,
+					Uid:      73025,
+					Gid:      5000,
+					Size:     16 << 30,
+					ModTime:  time.Unix(1254699560, 0),
+					Typeflag: '0',
+					Uname:    "dsymonds",
+					Gname:    "eng",
+				},
+				// fake contents
+				contents: strings.Repeat("\x00", 4<<10),
+			},
+		},
+	},
+	// The truncated test file was produced using these commands:
+	//   dd if=/dev/zero bs=1048576 count=16384 > (longname/)*15 /16gig.txt
+	//   tar -b 1 -c -f- (longname/)*15 /16gig.txt | dd bs=512 count=8 > writer-big-long.tar
+	{
+		file: "testdata/writer-big-long.tar",
+		entries: []*writerTestEntry{
+			{
+				header: &Header{
+					Name:     strings.Repeat("longname/", 15) + "16gig.txt",
+					Mode:     0644,
+					Uid:      1000,
+					Gid:      1000,
+					Size:     16 << 30,
+					ModTime:  time.Unix(1399583047, 0),
+					Typeflag: '0',
+					Uname:    "guillaume",
+					Gname:    "guillaume",
+				},
+				// fake contents
+				contents: strings.Repeat("\x00", 4<<10),
+			},
+		},
+	},
+	// This file was produced using gnu tar 1.17
+	// gnutar  -b 4 --format=ustar (longname/)*15 + file.txt
+	{
+		file: "testdata/ustar.tar",
+		entries: []*writerTestEntry{
+			{
+				header: &Header{
+					Name:     strings.Repeat("longname/", 15) + "file.txt",
+					Mode:     0644,
+					Uid:      0765,
+					Gid:      024,
+					Size:     06,
+					ModTime:  time.Unix(1360135598, 0),
+					Typeflag: '0',
+					Uname:    "shane",
+					Gname:    "staff",
+				},
+				contents: "hello\n",
+			},
+		},
+	},
+	// This file was produced using gnu tar 1.26
+	// echo "Slartibartfast" > file.txt
+	// ln file.txt hard.txt
+	// tar -b 1 --format=ustar -c -f hardlink.tar file.txt hard.txt
+	{
+		file: "testdata/hardlink.tar",
+		entries: []*writerTestEntry{
+			{
+				header: &Header{
+					Name:     "file.txt",
+					Mode:     0644,
+					Uid:      1000,
+					Gid:      100,
+					Size:     15,
+					ModTime:  time.Unix(1425484303, 0),
+					Typeflag: '0',
+					Uname:    "vbatts",
+					Gname:    "users",
+				},
+				contents: "Slartibartfast\n",
+			},
+			{
+				header: &Header{
+					Name:     "hard.txt",
+					Mode:     0644,
+					Uid:      1000,
+					Gid:      100,
+					Size:     0,
+					ModTime:  time.Unix(1425484303, 0),
+					Typeflag: '1',
+					Linkname: "file.txt",
+					Uname:    "vbatts",
+					Gname:    "users",
+				},
+				// no contents
+			},
+		},
+	},
+}
+
+// Render byte array in a two-character hexadecimal string, spaced for easy visual inspection.
+func bytestr(offset int, b []byte) string {
+	const rowLen = 32
+	s := fmt.Sprintf("%04x ", offset)
+	for _, ch := range b {
+		switch {
+		case '0' <= ch && ch <= '9', 'A' <= ch && ch <= 'Z', 'a' <= ch && ch <= 'z':
+			s += fmt.Sprintf("  %c", ch)
+		default:
+			s += fmt.Sprintf(" %02x", ch)
+		}
+	}
+	return s
+}
+
+// Render a pseudo-diff between two blocks of bytes.
+func bytediff(a []byte, b []byte) string {
+	const rowLen = 32
+	s := fmt.Sprintf("(%d bytes vs. %d bytes)\n", len(a), len(b))
+	for offset := 0; len(a)+len(b) > 0; offset += rowLen {
+		na, nb := rowLen, rowLen
+		if na > len(a) {
+			na = len(a)
+		}
+		if nb > len(b) {
+			nb = len(b)
+		}
+		sa := bytestr(offset, a[0:na])
+		sb := bytestr(offset, b[0:nb])
+		if sa != sb {
+			s += fmt.Sprintf("-%v\n+%v\n", sa, sb)
+		}
+		a = a[na:]
+		b = b[nb:]
+	}
+	return s
+}
+
+func TestWriter(t *testing.T) {
+testLoop:
+	for i, test := range writerTests {
+		expected, err := ioutil.ReadFile(test.file)
+		if err != nil {
+			t.Errorf("test %d: Unexpected error: %v", i, err)
+			continue
+		}
+
+		buf := new(bytes.Buffer)
+		tw := NewWriter(iotest.TruncateWriter(buf, 4<<10)) // only catch the first 4 KB
+		big := false
+		for j, entry := range test.entries {
+			big = big || entry.header.Size > 1<<10
+			if err := tw.WriteHeader(entry.header); err != nil {
+				t.Errorf("test %d, entry %d: Failed writing header: %v", i, j, err)
+				continue testLoop
+			}
+			if _, err := io.WriteString(tw, entry.contents); err != nil {
+				t.Errorf("test %d, entry %d: Failed writing contents: %v", i, j, err)
+				continue testLoop
+			}
+		}
+		// Only interested in Close failures for the small tests.
+		if err := tw.Close(); err != nil && !big {
+			t.Errorf("test %d: Failed closing archive: %v", i, err)
+			continue testLoop
+		}
+
+		actual := buf.Bytes()
+		if !bytes.Equal(expected, actual) {
+			t.Errorf("test %d: Incorrect result: (-=expected, +=actual)\n%v",
+				i, bytediff(expected, actual))
+		}
+		if testing.Short() { // The second test is expensive.
+			break
+		}
+	}
+}
+
+func TestPax(t *testing.T) {
+	// Create an archive with a large name
+	fileinfo, err := os.Stat("testdata/small.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	hdr, err := FileInfoHeader(fileinfo, "")
+	if err != nil {
+		t.Fatalf("os.Stat: %v", err)
+	}
+	// Force a PAX long name to be written
+	longName := strings.Repeat("ab", 100)
+	contents := strings.Repeat(" ", int(hdr.Size))
+	hdr.Name = longName
+	var buf bytes.Buffer
+	writer := NewWriter(&buf)
+	if err := writer.WriteHeader(hdr); err != nil {
+		t.Fatal(err)
+	}
+	if _, err = writer.Write([]byte(contents)); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	// Simple test to make sure PAX extensions are in effect
+	if !bytes.Contains(buf.Bytes(), []byte("PaxHeaders.0")) {
+		t.Fatal("Expected at least one PAX header to be written.")
+	}
+	// Test that we can get a long name back out of the archive.
+	reader := NewReader(&buf)
+	hdr, err = reader.Next()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if hdr.Name != longName {
+		t.Fatal("Couldn't recover long file name")
+	}
+}
+
+func TestPaxSymlink(t *testing.T) {
+	// Create an archive with a large linkname
+	fileinfo, err := os.Stat("testdata/small.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	hdr, err := FileInfoHeader(fileinfo, "")
+	hdr.Typeflag = TypeSymlink
+	if err != nil {
+		t.Fatalf("os.Stat:1 %v", err)
+	}
+	// Force a PAX long linkname to be written
+	longLinkname := strings.Repeat("1234567890/1234567890", 10)
+	hdr.Linkname = longLinkname
+
+	hdr.Size = 0
+	var buf bytes.Buffer
+	writer := NewWriter(&buf)
+	if err := writer.WriteHeader(hdr); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	// Simple test to make sure PAX extensions are in effect
+	if !bytes.Contains(buf.Bytes(), []byte("PaxHeaders.0")) {
+		t.Fatal("Expected at least one PAX header to be written.")
+	}
+	// Test that we can get a long name back out of the archive.
+	reader := NewReader(&buf)
+	hdr, err = reader.Next()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if hdr.Linkname != longLinkname {
+		t.Fatal("Couldn't recover long link name")
+	}
+}
+
+func TestPaxNonAscii(t *testing.T) {
+	// Create an archive with non ascii. These should trigger a pax header
+	// because pax headers have a defined utf-8 encoding.
+	fileinfo, err := os.Stat("testdata/small.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	hdr, err := FileInfoHeader(fileinfo, "")
+	if err != nil {
+		t.Fatalf("os.Stat:1 %v", err)
+	}
+
+	// some sample data
+	chineseFilename := "文件名"
+	chineseGroupname := "組"
+	chineseUsername := "用戶名"
+
+	hdr.Name = chineseFilename
+	hdr.Gname = chineseGroupname
+	hdr.Uname = chineseUsername
+
+	contents := strings.Repeat(" ", int(hdr.Size))
+
+	var buf bytes.Buffer
+	writer := NewWriter(&buf)
+	if err := writer.WriteHeader(hdr); err != nil {
+		t.Fatal(err)
+	}
+	if _, err = writer.Write([]byte(contents)); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	// Simple test to make sure PAX extensions are in effect
+	if !bytes.Contains(buf.Bytes(), []byte("PaxHeaders.0")) {
+		t.Fatal("Expected at least one PAX header to be written.")
+	}
+	// Test that we can get a long name back out of the archive.
+	reader := NewReader(&buf)
+	hdr, err = reader.Next()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if hdr.Name != chineseFilename {
+		t.Fatal("Couldn't recover unicode name")
+	}
+	if hdr.Gname != chineseGroupname {
+		t.Fatal("Couldn't recover unicode group")
+	}
+	if hdr.Uname != chineseUsername {
+		t.Fatal("Couldn't recover unicode user")
+	}
+}
+
+func TestPaxXattrs(t *testing.T) {
+	xattrs := map[string]string{
+		"user.key": "value",
+	}
+
+	// Create an archive with an xattr
+	fileinfo, err := os.Stat("testdata/small.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	hdr, err := FileInfoHeader(fileinfo, "")
+	if err != nil {
+		t.Fatalf("os.Stat: %v", err)
+	}
+	contents := "Kilts"
+	hdr.Xattrs = xattrs
+	var buf bytes.Buffer
+	writer := NewWriter(&buf)
+	if err := writer.WriteHeader(hdr); err != nil {
+		t.Fatal(err)
+	}
+	if _, err = writer.Write([]byte(contents)); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	// Test that we can get the xattrs back out of the archive.
+	reader := NewReader(&buf)
+	hdr, err = reader.Next()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(hdr.Xattrs, xattrs) {
+		t.Fatalf("xattrs did not survive round trip: got %+v, want %+v",
+			hdr.Xattrs, xattrs)
+	}
+}
+
+func TestPaxHeadersSorted(t *testing.T) {
+	fileinfo, err := os.Stat("testdata/small.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	hdr, err := FileInfoHeader(fileinfo, "")
+	if err != nil {
+		t.Fatalf("os.Stat: %v", err)
+	}
+	contents := strings.Repeat(" ", int(hdr.Size))
+
+	hdr.Xattrs = map[string]string{
+		"foo": "foo",
+		"bar": "bar",
+		"baz": "baz",
+		"qux": "qux",
+	}
+
+	var buf bytes.Buffer
+	writer := NewWriter(&buf)
+	if err := writer.WriteHeader(hdr); err != nil {
+		t.Fatal(err)
+	}
+	if _, err = writer.Write([]byte(contents)); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	// Simple test to make sure PAX extensions are in effect
+	if !bytes.Contains(buf.Bytes(), []byte("PaxHeaders.0")) {
+		t.Fatal("Expected at least one PAX header to be written.")
+	}
+
+	// xattr bar should always appear before others
+	indices := []int{
+		bytes.Index(buf.Bytes(), []byte("bar=bar")),
+		bytes.Index(buf.Bytes(), []byte("baz=baz")),
+		bytes.Index(buf.Bytes(), []byte("foo=foo")),
+		bytes.Index(buf.Bytes(), []byte("qux=qux")),
+	}
+	if !sort.IntsAreSorted(indices) {
+		t.Fatal("PAX headers are not sorted")
+	}
+}
+
+func TestUSTARLongName(t *testing.T) {
+	// Create an archive with a path that failed to split with USTAR extension in previous versions.
+	fileinfo, err := os.Stat("testdata/small.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	hdr, err := FileInfoHeader(fileinfo, "")
+	hdr.Typeflag = TypeDir
+	if err != nil {
+		t.Fatalf("os.Stat:1 %v", err)
+	}
+	// Force a PAX long name to be written. The name was taken from a practical example
+	// that fails and replaced ever char through numbers to anonymize the sample.
+	longName := "/0000_0000000/00000-000000000/0000_0000000/00000-0000000000000/0000_0000000/00000-0000000-00000000/0000_0000000/00000000/0000_0000000/000/0000_0000000/00000000v00/0000_0000000/000000/0000_0000000/0000000/0000_0000000/00000y-00/0000/0000/00000000/0x000000/"
+	hdr.Name = longName
+
+	hdr.Size = 0
+	var buf bytes.Buffer
+	writer := NewWriter(&buf)
+	if err := writer.WriteHeader(hdr); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	// Test that we can get a long name back out of the archive.
+	reader := NewReader(&buf)
+	hdr, err = reader.Next()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if hdr.Name != longName {
+		t.Fatal("Couldn't recover long name")
+	}
+}
+
+func TestValidTypeflagWithPAXHeader(t *testing.T) {
+	var buffer bytes.Buffer
+	tw := NewWriter(&buffer)
+
+	fileName := strings.Repeat("ab", 100)
+
+	hdr := &Header{
+		Name:     fileName,
+		Size:     4,
+		Typeflag: 0,
+	}
+	if err := tw.WriteHeader(hdr); err != nil {
+		t.Fatalf("Failed to write header: %s", err)
+	}
+	if _, err := tw.Write([]byte("fooo")); err != nil {
+		t.Fatalf("Failed to write the file's data: %s", err)
+	}
+	tw.Close()
+
+	tr := NewReader(&buffer)
+
+	for {
+		header, err := tr.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatalf("Failed to read header: %s", err)
+		}
+		if header.Typeflag != 0 {
+			t.Fatalf("Typeflag should've been 0, found %d", header.Typeflag)
+		}
+	}
+}
+
+func TestWriteAfterClose(t *testing.T) {
+	var buffer bytes.Buffer
+	tw := NewWriter(&buffer)
+
+	hdr := &Header{
+		Name: "small.txt",
+		Size: 5,
+	}
+	if err := tw.WriteHeader(hdr); err != nil {
+		t.Fatalf("Failed to write header: %s", err)
+	}
+	tw.Close()
+	if _, err := tw.Write([]byte("Kilts")); err != ErrWriteAfterClose {
+		t.Fatalf("Write: got %v; want ErrWriteAfterClose", err)
+	}
+}
+
+func TestSplitUSTARPath(t *testing.T) {
+	var sr = strings.Repeat
+
+	var vectors = []struct {
+		input  string // Input path
+		prefix string // Expected output prefix
+		suffix string // Expected output suffix
+		ok     bool   // Split success?
+	}{
+		{"", "", "", false},
+		{"abc", "", "", false},
+		{"用戶名", "", "", false},
+		{sr("a", fileNameSize), "", "", false},
+		{sr("a", fileNameSize) + "/", "", "", false},
+		{sr("a", fileNameSize) + "/a", sr("a", fileNameSize), "a", true},
+		{sr("a", fileNamePrefixSize) + "/", "", "", false},
+		{sr("a", fileNamePrefixSize) + "/a", sr("a", fileNamePrefixSize), "a", true},
+		{sr("a", fileNameSize+1), "", "", false},
+		{sr("/", fileNameSize+1), sr("/", fileNameSize-1), "/", true},
+		{sr("a", fileNamePrefixSize) + "/" + sr("b", fileNameSize),
+			sr("a", fileNamePrefixSize), sr("b", fileNameSize), true},
+		{sr("a", fileNamePrefixSize) + "//" + sr("b", fileNameSize), "", "", false},
+		{sr("a/", fileNameSize), sr("a/", 77) + "a", sr("a/", 22), true},
+	}
+
+	for _, v := range vectors {
+		prefix, suffix, ok := splitUSTARPath(v.input)
+		if prefix != v.prefix || suffix != v.suffix || ok != v.ok {
+			t.Errorf("splitUSTARPath(%q):\ngot  (%q, %q, %v)\nwant (%q, %q, %v)",
+				v.input, prefix, suffix, ok, v.prefix, v.suffix, v.ok)
+		}
+	}
+}
+
+func TestFormatPAXRecord(t *testing.T) {
+	var medName = strings.Repeat("CD", 50)
+	var longName = strings.Repeat("AB", 100)
+
+	var vectors = []struct {
+		inputKey string
+		inputVal string
+		output   string
+	}{
+		{"k", "v", "6 k=v\n"},
+		{"path", "/etc/hosts", "19 path=/etc/hosts\n"},
+		{"path", longName, "210 path=" + longName + "\n"},
+		{"path", medName, "110 path=" + medName + "\n"},
+		{"foo", "ba", "9 foo=ba\n"},
+		{"foo", "bar", "11 foo=bar\n"},
+		{"foo", "b=\nar=\n==\x00", "18 foo=b=\nar=\n==\x00\n"},
+		{"foo", "hello9 foo=ba\nworld", "27 foo=hello9 foo=ba\nworld\n"},
+		{"☺☻☹", "日a本b語ç", "27 ☺☻☹=日a本b語ç\n"},
+		{"\x00hello", "\x00world", "17 \x00hello=\x00world\n"},
+	}
+
+	for _, v := range vectors {
+		output := formatPAXRecord(v.inputKey, v.inputVal)
+		if output != v.output {
+			t.Errorf("formatPAXRecord(%q, %q): got %q, want %q",
+				v.inputKey, v.inputVal, output, v.output)
+		}
+	}
+}
+
+func TestFitsInBase256(t *testing.T) {
+	var vectors = []struct {
+		input int64
+		width int
+		ok    bool
+	}{
+		{+1, 8, true},
+		{0, 8, true},
+		{-1, 8, true},
+		{1 << 56, 8, false},
+		{(1 << 56) - 1, 8, true},
+		{-1 << 56, 8, true},
+		{(-1 << 56) - 1, 8, false},
+		{121654, 8, true},
+		{-9849849, 8, true},
+		{math.MaxInt64, 9, true},
+		{0, 9, true},
+		{math.MinInt64, 9, true},
+		{math.MaxInt64, 12, true},
+		{0, 12, true},
+		{math.MinInt64, 12, true},
+	}
+
+	for _, v := range vectors {
+		ok := fitsInBase256(v.width, v.input)
+		if ok != v.ok {
+			t.Errorf("checkNumeric(%d, %d): got %v, want %v", v.input, v.width, ok, v.ok)
+		}
+	}
+}
+
+func TestFormatNumeric(t *testing.T) {
+	var vectors = []struct {
+		input  int64
+		output string
+		ok     bool
+	}{
+		// Test base-256 (binary) encoded values.
+		{-1, "\xff", true},
+		{-1, "\xff\xff", true},
+		{-1, "\xff\xff\xff", true},
+		{(1 << 0), "0", false},
+		{(1 << 8) - 1, "\x80\xff", true},
+		{(1 << 8), "0\x00", false},
+		{(1 << 16) - 1, "\x80\xff\xff", true},
+		{(1 << 16), "00\x00", false},
+		{-1 * (1 << 0), "\xff", true},
+		{-1*(1<<0) - 1, "0", false},
+		{-1 * (1 << 8), "\xff\x00", true},
+		{-1*(1<<8) - 1, "0\x00", false},
+		{-1 * (1 << 16), "\xff\x00\x00", true},
+		{-1*(1<<16) - 1, "00\x00", false},
+		{537795476381659745, "0000000\x00", false},
+		{537795476381659745, "\x80\x00\x00\x00\x07\x76\xa2\x22\xeb\x8a\x72\x61", true},
+		{-615126028225187231, "0000000\x00", false},
+		{-615126028225187231, "\xff\xff\xff\xff\xf7\x76\xa2\x22\xeb\x8a\x72\x61", true},
+		{math.MaxInt64, "0000000\x00", false},
+		{math.MaxInt64, "\x80\x00\x00\x00\x7f\xff\xff\xff\xff\xff\xff\xff", true},
+		{math.MinInt64, "0000000\x00", false},
+		{math.MinInt64, "\xff\xff\xff\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
+		{math.MaxInt64, "\x80\x7f\xff\xff\xff\xff\xff\xff\xff", true},
+		{math.MinInt64, "\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
+	}
+
+	for _, v := range vectors {
+		var f formatter
+		output := make([]byte, len(v.output))
+		f.formatNumeric(output, v.input)
+		ok := (f.err == nil)
+		if ok != v.ok {
+			if v.ok {
+				t.Errorf("formatNumeric(%d): got formatting failure, want success", v.input)
+			} else {
+				t.Errorf("formatNumeric(%d): got formatting success, want failure", v.input)
+			}
+		}
+		if string(output) != v.output {
+			t.Errorf("formatNumeric(%d): got %q, want %q", v.input, output, v.output)
+		}
+	}
+}
+
+func TestFormatPAXTime(t *testing.T) {
+	t1 := time.Date(2000, 1, 1, 11, 0, 0, 0, time.UTC)
+	t2 := time.Date(2000, 1, 1, 11, 0, 0, 100, time.UTC)
+	t3 := time.Date(1960, 1, 1, 11, 0, 0, 0, time.UTC)
+	t4 := time.Date(1970, 1, 1, 0, 0, 0, 0, time.UTC)
+	verify := func(time time.Time, s string) {
+		p := formatPAXTime(time)
+		if p != s {
+			t.Errorf("for %v, expected %s, got %s", time, s, p)
+		}
+	}
+	verify(t1, "946724400")
+	verify(t2, "946724400.000000100")
+	verify(t3, "-315579600")
+	verify(t4, "0")
+}

vendor/github.com/Microsoft/go-winio/backup.go

@@ -0,0 +1,280 @@
+// +build windows
+
+package winio
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"runtime"
+	"syscall"
+	"unicode/utf16"
+)
+
+//sys backupRead(h syscall.Handle, b []byte, bytesRead *uint32, abort bool, processSecurity bool, context *uintptr) (err error) = BackupRead
+//sys backupWrite(h syscall.Handle, b []byte, bytesWritten *uint32, abort bool, processSecurity bool, context *uintptr) (err error) = BackupWrite
+
+const (
+	BackupData = uint32(iota + 1)
+	BackupEaData
+	BackupSecurity
+	BackupAlternateData
+	BackupLink
+	BackupPropertyData
+	BackupObjectId
+	BackupReparseData
+	BackupSparseBlock
+	BackupTxfsData
+)
+
+const (
+	StreamSparseAttributes = uint32(8)
+)
+
+const (
+	WRITE_DAC              = 0x40000
+	WRITE_OWNER            = 0x80000
+	ACCESS_SYSTEM_SECURITY = 0x1000000
+)
+
+// BackupHeader represents a backup stream of a file.
+type BackupHeader struct {
+	Id         uint32 // The backup stream ID
+	Attributes uint32 // Stream attributes
+	Size       int64  // The size of the stream in bytes
+	Name       string // The name of the stream (for BackupAlternateData only).
+	Offset     int64  // The offset of the stream in the file (for BackupSparseBlock only).
+}
+
+type win32StreamId struct {
+	StreamId   uint32
+	Attributes uint32
+	Size       uint64
+	NameSize   uint32
+}
+
+// BackupStreamReader reads from a stream produced by the BackupRead Win32 API and produces a series
+// of BackupHeader values.
+type BackupStreamReader struct {
+	r         io.Reader
+	bytesLeft int64
+}
+
+// NewBackupStreamReader produces a BackupStreamReader from any io.Reader.
+func NewBackupStreamReader(r io.Reader) *BackupStreamReader {
+	return &BackupStreamReader{r, 0}
+}
+
+// Next returns the next backup stream and prepares for calls to Read(). It skips the remainder of the current stream if
+// it was not completely read.
+func (r *BackupStreamReader) Next() (*BackupHeader, error) {
+	if r.bytesLeft > 0 {
+		if s, ok := r.r.(io.Seeker); ok {
+			// Make sure Seek on io.SeekCurrent sometimes succeeds
+			// before trying the actual seek.
+			if _, err := s.Seek(0, io.SeekCurrent); err == nil {
+				if _, err = s.Seek(r.bytesLeft, io.SeekCurrent); err != nil {
+					return nil, err
+				}
+				r.bytesLeft = 0
+			}
+		}
+		if _, err := io.Copy(ioutil.Discard, r); err != nil {
+			return nil, err
+		}
+	}
+	var wsi win32StreamId
+	if err := binary.Read(r.r, binary.LittleEndian, &wsi); err != nil {
+		return nil, err
+	}
+	hdr := &BackupHeader{
+		Id:         wsi.StreamId,
+		Attributes: wsi.Attributes,
+		Size:       int64(wsi.Size),
+	}
+	if wsi.NameSize != 0 {
+		name := make([]uint16, int(wsi.NameSize/2))
+		if err := binary.Read(r.r, binary.LittleEndian, name); err != nil {
+			return nil, err
+		}
+		hdr.Name = syscall.UTF16ToString(name)
+	}
+	if wsi.StreamId == BackupSparseBlock {
+		if err := binary.Read(r.r, binary.LittleEndian, &hdr.Offset); err != nil {
+			return nil, err
+		}
+		hdr.Size -= 8
+	}
+	r.bytesLeft = hdr.Size
+	return hdr, nil
+}
+
+// Read reads from the current backup stream.
+func (r *BackupStreamReader) Read(b []byte) (int, error) {
+	if r.bytesLeft == 0 {
+		return 0, io.EOF
+	}
+	if int64(len(b)) > r.bytesLeft {
+		b = b[:r.bytesLeft]
+	}
+	n, err := r.r.Read(b)
+	r.bytesLeft -= int64(n)
+	if err == io.EOF {
+		err = io.ErrUnexpectedEOF
+	} else if r.bytesLeft == 0 && err == nil {
+		err = io.EOF
+	}
+	return n, err
+}
+
+// BackupStreamWriter writes a stream compatible with the BackupWrite Win32 API.
+type BackupStreamWriter struct {
+	w         io.Writer
+	bytesLeft int64
+}
+
+// NewBackupStreamWriter produces a BackupStreamWriter on top of an io.Writer.
+func NewBackupStreamWriter(w io.Writer) *BackupStreamWriter {
+	return &BackupStreamWriter{w, 0}
+}
+
+// WriteHeader writes the next backup stream header and prepares for calls to Write().
+func (w *BackupStreamWriter) WriteHeader(hdr *BackupHeader) error {
+	if w.bytesLeft != 0 {
+		return fmt.Errorf("missing %d bytes", w.bytesLeft)
+	}
+	name := utf16.Encode([]rune(hdr.Name))
+	wsi := win32StreamId{
+		StreamId:   hdr.Id,
+		Attributes: hdr.Attributes,
+		Size:       uint64(hdr.Size),
+		NameSize:   uint32(len(name) * 2),
+	}
+	if hdr.Id == BackupSparseBlock {
+		// Include space for the int64 block offset
+		wsi.Size += 8
+	}
+	if err := binary.Write(w.w, binary.LittleEndian, &wsi); err != nil {
+		return err
+	}
+	if len(name) != 0 {
+		if err := binary.Write(w.w, binary.LittleEndian, name); err != nil {
+			return err
+		}
+	}
+	if hdr.Id == BackupSparseBlock {
+		if err := binary.Write(w.w, binary.LittleEndian, hdr.Offset); err != nil {
+			return err
+		}
+	}
+	w.bytesLeft = hdr.Size
+	return nil
+}
+
+// Write writes to the current backup stream.
+func (w *BackupStreamWriter) Write(b []byte) (int, error) {
+	if w.bytesLeft < int64(len(b)) {
+		return 0, fmt.Errorf("too many bytes by %d", int64(len(b))-w.bytesLeft)
+	}
+	n, err := w.w.Write(b)
+	w.bytesLeft -= int64(n)
+	return n, err
+}
+
+// BackupFileReader provides an io.ReadCloser interface on top of the BackupRead Win32 API.
+type BackupFileReader struct {
+	f               *os.File
+	includeSecurity bool
+	ctx             uintptr
+}
+
+// NewBackupFileReader returns a new BackupFileReader from a file handle. If includeSecurity is true,
+// Read will attempt to read the security descriptor of the file.
+func NewBackupFileReader(f *os.File, includeSecurity bool) *BackupFileReader {
+	r := &BackupFileReader{f, includeSecurity, 0}
+	return r
+}
+
+// Read reads a backup stream from the file by calling the Win32 API BackupRead().
+func (r *BackupFileReader) Read(b []byte) (int, error) {
+	var bytesRead uint32
+	err := backupRead(syscall.Handle(r.f.Fd()), b, &bytesRead, false, r.includeSecurity, &r.ctx)
+	if err != nil {
+		return 0, &os.PathError{"BackupRead", r.f.Name(), err}
+	}
+	runtime.KeepAlive(r.f)
+	if bytesRead == 0 {
+		return 0, io.EOF
+	}
+	return int(bytesRead), nil
+}
+
+// Close frees Win32 resources associated with the BackupFileReader. It does not close
+// the underlying file.
+func (r *BackupFileReader) Close() error {
+	if r.ctx != 0 {
+		backupRead(syscall.Handle(r.f.Fd()), nil, nil, true, false, &r.ctx)
+		runtime.KeepAlive(r.f)
+		r.ctx = 0
+	}
+	return nil
+}
+
+// BackupFileWriter provides an io.WriteCloser interface on top of the BackupWrite Win32 API.
+type BackupFileWriter struct {
+	f               *os.File
+	includeSecurity bool
+	ctx             uintptr
+}
+
+// NewBackupFileWriter returns a new BackupFileWriter from a file handle. If includeSecurity is true,
+// Write() will attempt to restore the security descriptor from the stream.
+func NewBackupFileWriter(f *os.File, includeSecurity bool) *BackupFileWriter {
+	w := &BackupFileWriter{f, includeSecurity, 0}
+	return w
+}
+
+// Write restores a portion of the file using the provided backup stream.
+func (w *BackupFileWriter) Write(b []byte) (int, error) {
+	var bytesWritten uint32
+	err := backupWrite(syscall.Handle(w.f.Fd()), b, &bytesWritten, false, w.includeSecurity, &w.ctx)
+	if err != nil {
+		return 0, &os.PathError{"BackupWrite", w.f.Name(), err}
+	}
+	runtime.KeepAlive(w.f)
+	if int(bytesWritten) != len(b) {
+		return int(bytesWritten), errors.New("not all bytes could be written")
+	}
+	return len(b), nil
+}
+
+// Close frees Win32 resources associated with the BackupFileWriter. It does not
+// close the underlying file.
+func (w *BackupFileWriter) Close() error {
+	if w.ctx != 0 {
+		backupWrite(syscall.Handle(w.f.Fd()), nil, nil, true, false, &w.ctx)
+		runtime.KeepAlive(w.f)
+		w.ctx = 0
+	}
+	return nil
+}
+
+// OpenForBackup opens a file or directory, potentially skipping access checks if the backup
+// or restore privileges have been acquired.
+//
+// If the file opened was a directory, it cannot be used with Readdir().
+func OpenForBackup(path string, access uint32, share uint32, createmode uint32) (*os.File, error) {
+	winPath, err := syscall.UTF16FromString(path)
+	if err != nil {
+		return nil, err
+	}
+	h, err := syscall.CreateFile(&winPath[0], access, share, nil, createmode, syscall.FILE_FLAG_BACKUP_SEMANTICS|syscall.FILE_FLAG_OPEN_REPARSE_POINT, 0)
+	if err != nil {
+		err = &os.PathError{Op: "open", Path: path, Err: err}
+		return nil, err
+	}
+	return os.NewFile(uintptr(h), path), nil
+}

vendor/github.com/Microsoft/go-winio/backup_test.go

@@ -0,0 +1,255 @@
+package winio
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"syscall"
+	"testing"
+)
+
+var testFileName string
+
+func TestMain(m *testing.M) {
+	f, err := ioutil.TempFile("", "tmp")
+	if err != nil {
+		panic(err)
+	}
+	testFileName = f.Name()
+	f.Close()
+	defer os.Remove(testFileName)
+	os.Exit(m.Run())
+}
+
+func makeTestFile(makeADS bool) error {
+	os.Remove(testFileName)
+	f, err := os.Create(testFileName)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = f.Write([]byte("testing 1 2 3\n"))
+	if err != nil {
+		return err
+	}
+	if makeADS {
+		a, err := os.Create(testFileName + ":ads.txt")
+		if err != nil {
+			return err
+		}
+		defer a.Close()
+		_, err = a.Write([]byte("alternate data stream\n"))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func TestBackupRead(t *testing.T) {
+	err := makeTestFile(true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	f, err := os.Open(testFileName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	r := NewBackupFileReader(f, false)
+	defer r.Close()
+	b, err := ioutil.ReadAll(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(b) == 0 {
+		t.Fatal("no data")
+	}
+}
+
+func TestBackupStreamRead(t *testing.T) {
+	err := makeTestFile(true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	f, err := os.Open(testFileName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	r := NewBackupFileReader(f, false)
+	defer r.Close()
+
+	br := NewBackupStreamReader(r)
+	gotData := false
+	gotAltData := false
+	for {
+		hdr, err := br.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		switch hdr.Id {
+		case BackupData:
+			if gotData {
+				t.Fatal("duplicate data")
+			}
+			if hdr.Name != "" {
+				t.Fatalf("unexpected name %s", hdr.Name)
+			}
+			b, err := ioutil.ReadAll(br)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if string(b) != "testing 1 2 3\n" {
+				t.Fatalf("incorrect data %v", b)
+			}
+			gotData = true
+		case BackupAlternateData:
+			if gotAltData {
+				t.Fatal("duplicate alt data")
+			}
+			if hdr.Name != ":ads.txt:$DATA" {
+				t.Fatalf("incorrect name %s", hdr.Name)
+			}
+			b, err := ioutil.ReadAll(br)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if string(b) != "alternate data stream\n" {
+				t.Fatalf("incorrect data %v", b)
+			}
+			gotAltData = true
+		default:
+			t.Fatalf("unknown stream ID %d", hdr.Id)
+		}
+	}
+	if !gotData || !gotAltData {
+		t.Fatal("missing stream")
+	}
+}
+
+func TestBackupStreamWrite(t *testing.T) {
+	f, err := os.Create(testFileName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	w := NewBackupFileWriter(f, false)
+	defer w.Close()
+
+	data := "testing 1 2 3\n"
+	altData := "alternate stream\n"
+
+	br := NewBackupStreamWriter(w)
+	err = br.WriteHeader(&BackupHeader{Id: BackupData, Size: int64(len(data))})
+	if err != nil {
+		t.Fatal(err)
+	}
+	n, err := br.Write([]byte(data))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != len(data) {
+		t.Fatal("short write")
+	}
+
+	err = br.WriteHeader(&BackupHeader{Id: BackupAlternateData, Size: int64(len(altData)), Name: ":ads.txt:$DATA"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	n, err = br.Write([]byte(altData))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != len(altData) {
+		t.Fatal("short write")
+	}
+
+	f.Close()
+
+	b, err := ioutil.ReadFile(testFileName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(b) != data {
+		t.Fatalf("wrong data %v", b)
+	}
+
+	b, err = ioutil.ReadFile(testFileName + ":ads.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(b) != altData {
+		t.Fatalf("wrong data %v", b)
+	}
+}
+
+func makeSparseFile() error {
+	os.Remove(testFileName)
+	f, err := os.Create(testFileName)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	const (
+		FSCTL_SET_SPARSE    = 0x000900c4
+		FSCTL_SET_ZERO_DATA = 0x000980c8
+	)
+
+	err = syscall.DeviceIoControl(syscall.Handle(f.Fd()), FSCTL_SET_SPARSE, nil, 0, nil, 0, nil, nil)
+	if err != nil {
+		return err
+	}
+
+	_, err = f.Write([]byte("testing 1 2 3\n"))
+	if err != nil {
+		return err
+	}
+
+	_, err = f.Seek(1000000, 0)
+	if err != nil {
+		return err
+	}
+
+	_, err = f.Write([]byte("more data later\n"))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func TestBackupSparseFile(t *testing.T) {
+	err := makeSparseFile()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	f, err := os.Open(testFileName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	r := NewBackupFileReader(f, false)
+	defer r.Close()
+
+	br := NewBackupStreamReader(r)
+	for {
+		hdr, err := br.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		t.Log(hdr)
+	}
+}

vendor/github.com/Microsoft/go-winio/backuptar/noop.go

@@ -0,0 +1,4 @@
+// +build !windows
+// This file only exists to allow go get on non-Windows platforms.
+
+package backuptar

vendor/github.com/Microsoft/go-winio/backuptar/tar.go

@@ -0,0 +1,439 @@
+// +build windows
+
+package backuptar
+
+import (
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/go-winio/archive/tar" // until archive/tar supports pax extensions in its interface
+)
+
+const (
+	c_ISUID  = 04000   // Set uid
+	c_ISGID  = 02000   // Set gid
+	c_ISVTX  = 01000   // Save text (sticky bit)
+	c_ISDIR  = 040000  // Directory
+	c_ISFIFO = 010000  // FIFO
+	c_ISREG  = 0100000 // Regular file
+	c_ISLNK  = 0120000 // Symbolic link
+	c_ISBLK  = 060000  // Block special file
+	c_ISCHR  = 020000  // Character special file
+	c_ISSOCK = 0140000 // Socket
+)
+
+const (
+	hdrFileAttributes        = "fileattr"
+	hdrSecurityDescriptor    = "sd"
+	hdrRawSecurityDescriptor = "rawsd"
+	hdrMountPoint            = "mountpoint"
+	hdrEaPrefix              = "xattr."
+)
+
+func writeZeroes(w io.Writer, count int64) error {
+	buf := make([]byte, 8192)
+	c := len(buf)
+	for i := int64(0); i < count; i += int64(c) {
+		if int64(c) > count-i {
+			c = int(count - i)
+		}
+		_, err := w.Write(buf[:c])
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func copySparse(t *tar.Writer, br *winio.BackupStreamReader) error {
+	curOffset := int64(0)
+	for {
+		bhdr, err := br.Next()
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		if err != nil {
+			return err
+		}
+		if bhdr.Id != winio.BackupSparseBlock {
+			return fmt.Errorf("unexpected stream %d", bhdr.Id)
+		}
+
+		// archive/tar does not support writing sparse files
+		// so just write zeroes to catch up to the current offset.
+		err = writeZeroes(t, bhdr.Offset-curOffset)
+		if bhdr.Size == 0 {
+			break
+		}
+		n, err := io.Copy(t, br)
+		if err != nil {
+			return err
+		}
+		curOffset = bhdr.Offset + n
+	}
+	return nil
+}
+
+// BasicInfoHeader creates a tar header from basic file information.
+func BasicInfoHeader(name string, size int64, fileInfo *winio.FileBasicInfo) *tar.Header {
+	hdr := &tar.Header{
+		Name:         filepath.ToSlash(name),
+		Size:         size,
+		Typeflag:     tar.TypeReg,
+		ModTime:      time.Unix(0, fileInfo.LastWriteTime.Nanoseconds()),
+		ChangeTime:   time.Unix(0, fileInfo.ChangeTime.Nanoseconds()),
+		AccessTime:   time.Unix(0, fileInfo.LastAccessTime.Nanoseconds()),
+		CreationTime: time.Unix(0, fileInfo.CreationTime.Nanoseconds()),
+		Winheaders:   make(map[string]string),
+	}
+	hdr.Winheaders[hdrFileAttributes] = fmt.Sprintf("%d", fileInfo.FileAttributes)
+
+	if (fileInfo.FileAttributes & syscall.FILE_ATTRIBUTE_DIRECTORY) != 0 {
+		hdr.Mode |= c_ISDIR
+		hdr.Size = 0
+		hdr.Typeflag = tar.TypeDir
+	}
+	return hdr
+}
+
+// WriteTarFileFromBackupStream writes a file to a tar writer using data from a Win32 backup stream.
+//
+// This encodes Win32 metadata as tar pax vendor extensions starting with MSWINDOWS.
+//
+// The additional Win32 metadata is:
+//
+// MSWINDOWS.fileattr: The Win32 file attributes, as a decimal value
+//
+// MSWINDOWS.rawsd: The Win32 security descriptor, in raw binary format
+//
+// MSWINDOWS.mountpoint: If present, this is a mount point and not a symlink, even though the type is '2' (symlink)
+func WriteTarFileFromBackupStream(t *tar.Writer, r io.Reader, name string, size int64, fileInfo *winio.FileBasicInfo) error {
+	name = filepath.ToSlash(name)
+	hdr := BasicInfoHeader(name, size, fileInfo)
+
+	// If r can be seeked, then this function is two-pass: pass 1 collects the
+	// tar header data, and pass 2 copies the data stream. If r cannot be
+	// seeked, then some header data (in particular EAs) will be silently lost.
+	var (
+		restartPos int64
+		err        error
+	)
+	sr, readTwice := r.(io.Seeker)
+	if readTwice {
+		if restartPos, err = sr.Seek(0, io.SeekCurrent); err != nil {
+			readTwice = false
+		}
+	}
+
+	br := winio.NewBackupStreamReader(r)
+	var dataHdr *winio.BackupHeader
+	for dataHdr == nil {
+		bhdr, err := br.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		switch bhdr.Id {
+		case winio.BackupData:
+			hdr.Mode |= c_ISREG
+			if !readTwice {
+				dataHdr = bhdr
+			}
+		case winio.BackupSecurity:
+			sd, err := ioutil.ReadAll(br)
+			if err != nil {
+				return err
+			}
+			hdr.Winheaders[hdrRawSecurityDescriptor] = base64.StdEncoding.EncodeToString(sd)
+
+		case winio.BackupReparseData:
+			hdr.Mode |= c_ISLNK
+			hdr.Typeflag = tar.TypeSymlink
+			reparseBuffer, err := ioutil.ReadAll(br)
+			rp, err := winio.DecodeReparsePoint(reparseBuffer)
+			if err != nil {
+				return err
+			}
+			if rp.IsMountPoint {
+				hdr.Winheaders[hdrMountPoint] = "1"
+			}
+			hdr.Linkname = rp.Target
+
+		case winio.BackupEaData:
+			eab, err := ioutil.ReadAll(br)
+			if err != nil {
+				return err
+			}
+			eas, err := winio.DecodeExtendedAttributes(eab)
+			if err != nil {
+				return err
+			}
+			for _, ea := range eas {
+				// Use base64 encoding for the binary value. Note that there
+				// is no way to encode the EA's flags, since their use doesn't
+				// make any sense for persisted EAs.
+				hdr.Winheaders[hdrEaPrefix+ea.Name] = base64.StdEncoding.EncodeToString(ea.Value)
+			}
+
+		case winio.BackupAlternateData, winio.BackupLink, winio.BackupPropertyData, winio.BackupObjectId, winio.BackupTxfsData:
+			// ignore these streams
+		default:
+			return fmt.Errorf("%s: unknown stream ID %d", name, bhdr.Id)
+		}
+	}
+
+	err = t.WriteHeader(hdr)
+	if err != nil {
+		return err
+	}
+
+	if readTwice {
+		// Get back to the data stream.
+		if _, err = sr.Seek(restartPos, io.SeekStart); err != nil {
+			return err
+		}
+		for dataHdr == nil {
+			bhdr, err := br.Next()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return err
+			}
+			if bhdr.Id == winio.BackupData {
+				dataHdr = bhdr
+			}
+		}
+	}
+
+	if dataHdr != nil {
+		// A data stream was found. Copy the data.
+		if (dataHdr.Attributes & winio.StreamSparseAttributes) == 0 {
+			if size != dataHdr.Size {
+				return fmt.Errorf("%s: mismatch between file size %d and header size %d", name, size, dataHdr.Size)
+			}
+			_, err = io.Copy(t, br)
+			if err != nil {
+				return err
+			}
+		} else {
+			err = copySparse(t, br)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	// Look for streams after the data stream. The only ones we handle are alternate data streams.
+	// Other streams may have metadata that could be serialized, but the tar header has already
+	// been written. In practice, this means that we don't get EA or TXF metadata.
+	for {
+		bhdr, err := br.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		switch bhdr.Id {
+		case winio.BackupAlternateData:
+			altName := bhdr.Name
+			if strings.HasSuffix(altName, ":$DATA") {
+				altName = altName[:len(altName)-len(":$DATA")]
+			}
+			if (bhdr.Attributes & winio.StreamSparseAttributes) == 0 {
+				hdr = &tar.Header{
+					Name:       name + altName,
+					Mode:       hdr.Mode,
+					Typeflag:   tar.TypeReg,
+					Size:       bhdr.Size,
+					ModTime:    hdr.ModTime,
+					AccessTime: hdr.AccessTime,
+					ChangeTime: hdr.ChangeTime,
+				}
+				err = t.WriteHeader(hdr)
+				if err != nil {
+					return err
+				}
+				_, err = io.Copy(t, br)
+				if err != nil {
+					return err
+				}
+
+			} else {
+				// Unsupported for now, since the size of the alternate stream is not present
+				// in the backup stream until after the data has been read.
+				return errors.New("tar of sparse alternate data streams is unsupported")
+			}
+		case winio.BackupEaData, winio.BackupLink, winio.BackupPropertyData, winio.BackupObjectId, winio.BackupTxfsData:
+			// ignore these streams
+		default:
+			return fmt.Errorf("%s: unknown stream ID %d after data", name, bhdr.Id)
+		}
+	}
+	return nil
+}
+
+// FileInfoFromHeader retrieves basic Win32 file information from a tar header, using the additional metadata written by
+// WriteTarFileFromBackupStream.
+func FileInfoFromHeader(hdr *tar.Header) (name string, size int64, fileInfo *winio.FileBasicInfo, err error) {
+	name = hdr.Name
+	if hdr.Typeflag == tar.TypeReg || hdr.Typeflag == tar.TypeRegA {
+		size = hdr.Size
+	}
+	fileInfo = &winio.FileBasicInfo{
+		LastAccessTime: syscall.NsecToFiletime(hdr.AccessTime.UnixNano()),
+		LastWriteTime:  syscall.NsecToFiletime(hdr.ModTime.UnixNano()),
+		ChangeTime:     syscall.NsecToFiletime(hdr.ChangeTime.UnixNano()),
+		CreationTime:   syscall.NsecToFiletime(hdr.CreationTime.UnixNano()),
+	}
+	if attrStr, ok := hdr.Winheaders[hdrFileAttributes]; ok {
+		attr, err := strconv.ParseUint(attrStr, 10, 32)
+		if err != nil {
+			return "", 0, nil, err
+		}
+		fileInfo.FileAttributes = uint32(attr)
+	} else {
+		if hdr.Typeflag == tar.TypeDir {
+			fileInfo.FileAttributes |= syscall.FILE_ATTRIBUTE_DIRECTORY
+		}
+	}
+	return
+}
+
+// WriteBackupStreamFromTarFile writes a Win32 backup stream from the current tar file. Since this function may process multiple
+// tar file entries in order to collect all the alternate data streams for the file, it returns the next
+// tar file that was not processed, or io.EOF is there are no more.
+func WriteBackupStreamFromTarFile(w io.Writer, t *tar.Reader, hdr *tar.Header) (*tar.Header, error) {
+	bw := winio.NewBackupStreamWriter(w)
+	var sd []byte
+	var err error
+	// Maintaining old SDDL-based behavior for backward compatibility.  All new tar headers written
+	// by this library will have raw binary for the security descriptor.
+	if sddl, ok := hdr.Winheaders[hdrSecurityDescriptor]; ok {
+		sd, err = winio.SddlToSecurityDescriptor(sddl)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if sdraw, ok := hdr.Winheaders[hdrRawSecurityDescriptor]; ok {
+		sd, err = base64.StdEncoding.DecodeString(sdraw)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if len(sd) != 0 {
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupSecurity,
+			Size: int64(len(sd)),
+		}
+		err := bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = bw.Write(sd)
+		if err != nil {
+			return nil, err
+		}
+	}
+	var eas []winio.ExtendedAttribute
+	for k, v := range hdr.Winheaders {
+		if !strings.HasPrefix(k, hdrEaPrefix) {
+			continue
+		}
+		data, err := base64.StdEncoding.DecodeString(v)
+		if err != nil {
+			return nil, err
+		}
+		eas = append(eas, winio.ExtendedAttribute{
+			Name:  k[len(hdrEaPrefix):],
+			Value: data,
+		})
+	}
+	if len(eas) != 0 {
+		eadata, err := winio.EncodeExtendedAttributes(eas)
+		if err != nil {
+			return nil, err
+		}
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupEaData,
+			Size: int64(len(eadata)),
+		}
+		err = bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = bw.Write(eadata)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if hdr.Typeflag == tar.TypeSymlink {
+		_, isMountPoint := hdr.Winheaders[hdrMountPoint]
+		rp := winio.ReparsePoint{
+			Target:       filepath.FromSlash(hdr.Linkname),
+			IsMountPoint: isMountPoint,
+		}
+		reparse := winio.EncodeReparsePoint(&rp)
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupReparseData,
+			Size: int64(len(reparse)),
+		}
+		err := bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = bw.Write(reparse)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if hdr.Typeflag == tar.TypeReg || hdr.Typeflag == tar.TypeRegA {
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupData,
+			Size: hdr.Size,
+		}
+		err := bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = io.Copy(bw, t)
+		if err != nil {
+			return nil, err
+		}
+	}
+	// Copy all the alternate data streams and return the next non-ADS header.
+	for {
+		ahdr, err := t.Next()
+		if err != nil {
+			return nil, err
+		}
+		if ahdr.Typeflag != tar.TypeReg || !strings.HasPrefix(ahdr.Name, hdr.Name+":") {
+			return ahdr, nil
+		}
+		bhdr := winio.BackupHeader{
+			Id:   winio.BackupAlternateData,
+			Size: ahdr.Size,
+			Name: ahdr.Name[len(hdr.Name):] + ":$DATA",
+		}
+		err = bw.WriteHeader(&bhdr)
+		if err != nil {
+			return nil, err
+		}
+		_, err = io.Copy(bw, t)
+		if err != nil {
+			return nil, err
+		}
+	}
+}

vendor/github.com/Microsoft/go-winio/backuptar/tar_test.go

@@ -0,0 +1,84 @@
+package backuptar
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"testing"
+
+	"github.com/Microsoft/go-winio"
+	"github.com/Microsoft/go-winio/archive/tar"
+)
+
+func ensurePresent(t *testing.T, m map[string]string, keys ...string) {
+	for _, k := range keys {
+		if _, ok := m[k]; !ok {
+			t.Error(k, "not present in tar header")
+		}
+	}
+}
+
+func TestRoundTrip(t *testing.T) {
+	f, err := ioutil.TempFile("", "tst")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	defer os.Remove(f.Name())
+
+	if _, err = f.Write([]byte("testing 1 2 3\n")); err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err = f.Seek(0, 0); err != nil {
+		t.Fatal(err)
+	}
+
+	fi, err := f.Stat()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	bi, err := winio.GetFileBasicInfo(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	br := winio.NewBackupFileReader(f, true)
+	defer br.Close()
+
+	var buf bytes.Buffer
+	tw := tar.NewWriter(&buf)
+
+	err = WriteTarFileFromBackupStream(tw, br, f.Name(), fi.Size(), bi)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tr := tar.NewReader(&buf)
+	hdr, err := tr.Next()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	name, size, bi2, err := FileInfoFromHeader(hdr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if name != filepath.ToSlash(f.Name()) {
+		t.Errorf("got name %s, expected %s", name, filepath.ToSlash(f.Name()))
+	}
+
+	if size != fi.Size() {
+		t.Errorf("got size %d, expected %d", size, fi.Size())
+	}
+
+	if !reflect.DeepEqual(*bi, *bi2) {
+		t.Errorf("got %#v, expected %#v", *bi, *bi2)
+	}
+
+	ensurePresent(t, hdr.Winheaders, "fileattr", "rawsd")
+}

vendor/github.com/Microsoft/go-winio/ea.go

@@ -0,0 +1,137 @@
+package winio
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+)
+
+type fileFullEaInformation struct {
+	NextEntryOffset uint32
+	Flags           uint8
+	NameLength      uint8
+	ValueLength     uint16
+}
+
+var (
+	fileFullEaInformationSize = binary.Size(&fileFullEaInformation{})
+
+	errInvalidEaBuffer = errors.New("invalid extended attribute buffer")
+	errEaNameTooLarge  = errors.New("extended attribute name too large")
+	errEaValueTooLarge = errors.New("extended attribute value too large")
+)
+
+// ExtendedAttribute represents a single Windows EA.
+type ExtendedAttribute struct {
+	Name  string
+	Value []byte
+	Flags uint8
+}
+
+func parseEa(b []byte) (ea ExtendedAttribute, nb []byte, err error) {
+	var info fileFullEaInformation
+	err = binary.Read(bytes.NewReader(b), binary.LittleEndian, &info)
+	if err != nil {
+		err = errInvalidEaBuffer
+		return
+	}
+
+	nameOffset := fileFullEaInformationSize
+	nameLen := int(info.NameLength)
+	valueOffset := nameOffset + int(info.NameLength) + 1
+	valueLen := int(info.ValueLength)
+	nextOffset := int(info.NextEntryOffset)
+	if valueLen+valueOffset > len(b) || nextOffset < 0 || nextOffset > len(b) {
+		err = errInvalidEaBuffer
+		return
+	}
+
+	ea.Name = string(b[nameOffset : nameOffset+nameLen])
+	ea.Value = b[valueOffset : valueOffset+valueLen]
+	ea.Flags = info.Flags
+	if info.NextEntryOffset != 0 {
+		nb = b[info.NextEntryOffset:]
+	}
+	return
+}
+
+// DecodeExtendedAttributes decodes a list of EAs from a FILE_FULL_EA_INFORMATION
+// buffer retrieved from BackupRead, ZwQueryEaFile, etc.
+func DecodeExtendedAttributes(b []byte) (eas []ExtendedAttribute, err error) {
+	for len(b) != 0 {
+		ea, nb, err := parseEa(b)
+		if err != nil {
+			return nil, err
+		}
+
+		eas = append(eas, ea)
+		b = nb
+	}
+	return
+}
+
+func writeEa(buf *bytes.Buffer, ea *ExtendedAttribute, last bool) error {
+	if int(uint8(len(ea.Name))) != len(ea.Name) {
+		return errEaNameTooLarge
+	}
+	if int(uint16(len(ea.Value))) != len(ea.Value) {
+		return errEaValueTooLarge
+	}
+	entrySize := uint32(fileFullEaInformationSize + len(ea.Name) + 1 + len(ea.Value))
+	withPadding := (entrySize + 3) &^ 3
+	nextOffset := uint32(0)
+	if !last {
+		nextOffset = withPadding
+	}
+	info := fileFullEaInformation{
+		NextEntryOffset: nextOffset,
+		Flags:           ea.Flags,
+		NameLength:      uint8(len(ea.Name)),
+		ValueLength:     uint16(len(ea.Value)),
+	}
+
+	err := binary.Write(buf, binary.LittleEndian, &info)
+	if err != nil {
+		return err
+	}
+
+	_, err = buf.Write([]byte(ea.Name))
+	if err != nil {
+		return err
+	}
+
+	err = buf.WriteByte(0)
+	if err != nil {
+		return err
+	}
+
+	_, err = buf.Write(ea.Value)
+	if err != nil {
+		return err
+	}
+
+	_, err = buf.Write([]byte{0, 0, 0}[0 : withPadding-entrySize])
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// EncodeExtendedAttributes encodes a list of EAs into a FILE_FULL_EA_INFORMATION
+// buffer for use with BackupWrite, ZwSetEaFile, etc.
+func EncodeExtendedAttributes(eas []ExtendedAttribute) ([]byte, error) {
+	var buf bytes.Buffer
+	for i := range eas {
+		last := false
+		if i == len(eas)-1 {
+			last = true
+		}
+
+		err := writeEa(&buf, &eas[i], last)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return buf.Bytes(), nil
+}

vendor/github.com/Microsoft/go-winio/ea_test.go

@@ -0,0 +1,89 @@
+package winio
+
+import (
+	"io/ioutil"
+	"os"
+	"reflect"
+	"syscall"
+	"testing"
+	"unsafe"
+)
+
+var (
+	testEas = []ExtendedAttribute{
+		{Name: "foo", Value: []byte("bar")},
+		{Name: "fizz", Value: []byte("buzz")},
+	}
+
+	testEasEncoded   = []byte{16, 0, 0, 0, 0, 3, 3, 0, 102, 111, 111, 0, 98, 97, 114, 0, 0, 0, 0, 0, 0, 4, 4, 0, 102, 105, 122, 122, 0, 98, 117, 122, 122, 0, 0, 0}
+	testEasNotPadded = testEasEncoded[0 : len(testEasEncoded)-3]
+	testEasTruncated = testEasEncoded[0:20]
+)
+
+func Test_RoundTripEas(t *testing.T) {
+	b, err := EncodeExtendedAttributes(testEas)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(testEasEncoded, b) {
+		t.Fatalf("encoded mismatch %v %v", testEasEncoded, b)
+	}
+	eas, err := DecodeExtendedAttributes(b)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(testEas, eas) {
+		t.Fatalf("mismatch %+v %+v", testEas, eas)
+	}
+}
+
+func Test_EasDontNeedPaddingAtEnd(t *testing.T) {
+	eas, err := DecodeExtendedAttributes(testEasNotPadded)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(testEas, eas) {
+		t.Fatalf("mismatch %+v %+v", testEas, eas)
+	}
+}
+
+func Test_TruncatedEasFailCorrectly(t *testing.T) {
+	_, err := DecodeExtendedAttributes(testEasTruncated)
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}
+
+func Test_NilEasEncodeAndDecodeAsNil(t *testing.T) {
+	b, err := EncodeExtendedAttributes(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(b) != 0 {
+		t.Fatal("expected empty")
+	}
+	eas, err := DecodeExtendedAttributes(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(eas) != 0 {
+		t.Fatal("expected empty")
+	}
+}
+
+// Test_SetFileEa makes sure that the test buffer is actually parsable by NtSetEaFile.
+func Test_SetFileEa(t *testing.T) {
+	f, err := ioutil.TempFile("", "winio")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove(f.Name())
+	defer f.Close()
+	ntdll := syscall.MustLoadDLL("ntdll.dll")
+	ntSetEaFile := ntdll.MustFindProc("NtSetEaFile")
+	var iosb [2]uintptr
+	r, _, _ := ntSetEaFile.Call(f.Fd(), uintptr(unsafe.Pointer(&iosb[0])), uintptr(unsafe.Pointer(&testEasEncoded[0])), uintptr(len(testEasEncoded)))
+	if r != 0 {
+		t.Fatalf("NtSetEaFile failed with %08x", r)
+	}
+}

vendor/github.com/Microsoft/go-winio/file.go

@@ -0,0 +1,307 @@
+// +build windows
+
+package winio
+
+import (
+	"errors"
+	"io"
+	"runtime"
+	"sync"
+	"sync/atomic"
+	"syscall"
+	"time"
+)
+
+//sys cancelIoEx(file syscall.Handle, o *syscall.Overlapped) (err error) = CancelIoEx
+//sys createIoCompletionPort(file syscall.Handle, port syscall.Handle, key uintptr, threadCount uint32) (newport syscall.Handle, err error) = CreateIoCompletionPort
+//sys getQueuedCompletionStatus(port syscall.Handle, bytes *uint32, key *uintptr, o **ioOperation, timeout uint32) (err error) = GetQueuedCompletionStatus
+//sys setFileCompletionNotificationModes(h syscall.Handle, flags uint8) (err error) = SetFileCompletionNotificationModes
+
+type atomicBool int32
+
+func (b *atomicBool) isSet() bool { return atomic.LoadInt32((*int32)(b)) != 0 }
+func (b *atomicBool) setFalse()   { atomic.StoreInt32((*int32)(b), 0) }
+func (b *atomicBool) setTrue()    { atomic.StoreInt32((*int32)(b), 1) }
+func (b *atomicBool) swap(new bool) bool {
+	var newInt int32
+	if new {
+		newInt = 1
+	}
+	return atomic.SwapInt32((*int32)(b), newInt) == 1
+}
+
+const (
+	cFILE_SKIP_COMPLETION_PORT_ON_SUCCESS = 1
+	cFILE_SKIP_SET_EVENT_ON_HANDLE        = 2
+)
+
+var (
+	ErrFileClosed = errors.New("file has already been closed")
+	ErrTimeout    = &timeoutError{}
+)
+
+type timeoutError struct{}
+
+func (e *timeoutError) Error() string   { return "i/o timeout" }
+func (e *timeoutError) Timeout() bool   { return true }
+func (e *timeoutError) Temporary() bool { return true }
+
+type timeoutChan chan struct{}
+
+var ioInitOnce sync.Once
+var ioCompletionPort syscall.Handle
+
+// ioResult contains the result of an asynchronous IO operation
+type ioResult struct {
+	bytes uint32
+	err   error
+}
+
+// ioOperation represents an outstanding asynchronous Win32 IO
+type ioOperation struct {
+	o  syscall.Overlapped
+	ch chan ioResult
+}
+
+func initIo() {
+	h, err := createIoCompletionPort(syscall.InvalidHandle, 0, 0, 0xffffffff)
+	if err != nil {
+		panic(err)
+	}
+	ioCompletionPort = h
+	go ioCompletionProcessor(h)
+}
+
+// win32File implements Reader, Writer, and Closer on a Win32 handle without blocking in a syscall.
+// It takes ownership of this handle and will close it if it is garbage collected.
+type win32File struct {
+	handle        syscall.Handle
+	wg            sync.WaitGroup
+	wgLock        sync.RWMutex
+	closing       atomicBool
+	readDeadline  deadlineHandler
+	writeDeadline deadlineHandler
+}
+
+type deadlineHandler struct {
+	setLock     sync.Mutex
+	channel     timeoutChan
+	channelLock sync.RWMutex
+	timer       *time.Timer
+	timedout    atomicBool
+}
+
+// makeWin32File makes a new win32File from an existing file handle
+func makeWin32File(h syscall.Handle) (*win32File, error) {
+	f := &win32File{handle: h}
+	ioInitOnce.Do(initIo)
+	_, err := createIoCompletionPort(h, ioCompletionPort, 0, 0xffffffff)
+	if err != nil {
+		return nil, err
+	}
+	err = setFileCompletionNotificationModes(h, cFILE_SKIP_COMPLETION_PORT_ON_SUCCESS|cFILE_SKIP_SET_EVENT_ON_HANDLE)
+	if err != nil {
+		return nil, err
+	}
+	f.readDeadline.channel = make(timeoutChan)
+	f.writeDeadline.channel = make(timeoutChan)
+	return f, nil
+}
+
+func MakeOpenFile(h syscall.Handle) (io.ReadWriteCloser, error) {
+	return makeWin32File(h)
+}
+
+// closeHandle closes the resources associated with a Win32 handle
+func (f *win32File) closeHandle() {
+	f.wgLock.Lock()
+	// Atomically set that we are closing, releasing the resources only once.
+	if !f.closing.swap(true) {
+		f.wgLock.Unlock()
+		// cancel all IO and wait for it to complete
+		cancelIoEx(f.handle, nil)
+		f.wg.Wait()
+		// at this point, no new IO can start
+		syscall.Close(f.handle)
+		f.handle = 0
+	} else {
+		f.wgLock.Unlock()
+	}
+}
+
+// Close closes a win32File.
+func (f *win32File) Close() error {
+	f.closeHandle()
+	return nil
+}
+
+// prepareIo prepares for a new IO operation.
+// The caller must call f.wg.Done() when the IO is finished, prior to Close() returning.
+func (f *win32File) prepareIo() (*ioOperation, error) {
+	f.wgLock.RLock()
+	if f.closing.isSet() {
+		f.wgLock.RUnlock()
+		return nil, ErrFileClosed
+	}
+	f.wg.Add(1)
+	f.wgLock.RUnlock()
+	c := &ioOperation{}
+	c.ch = make(chan ioResult)
+	return c, nil
+}
+
+// ioCompletionProcessor processes completed async IOs forever
+func ioCompletionProcessor(h syscall.Handle) {
+	for {
+		var bytes uint32
+		var key uintptr
+		var op *ioOperation
+		err := getQueuedCompletionStatus(h, &bytes, &key, &op, syscall.INFINITE)
+		if op == nil {
+			panic(err)
+		}
+		op.ch <- ioResult{bytes, err}
+	}
+}
+
+// asyncIo processes the return value from ReadFile or WriteFile, blocking until
+// the operation has actually completed.
+func (f *win32File) asyncIo(c *ioOperation, d *deadlineHandler, bytes uint32, err error) (int, error) {
+	if err != syscall.ERROR_IO_PENDING {
+		return int(bytes), err
+	}
+
+	if f.closing.isSet() {
+		cancelIoEx(f.handle, &c.o)
+	}
+
+	var timeout timeoutChan
+	if d != nil {
+		d.channelLock.Lock()
+		timeout = d.channel
+		d.channelLock.Unlock()
+	}
+
+	var r ioResult
+	select {
+	case r = <-c.ch:
+		err = r.err
+		if err == syscall.ERROR_OPERATION_ABORTED {
+			if f.closing.isSet() {
+				err = ErrFileClosed
+			}
+		}
+	case <-timeout:
+		cancelIoEx(f.handle, &c.o)
+		r = <-c.ch
+		err = r.err
+		if err == syscall.ERROR_OPERATION_ABORTED {
+			err = ErrTimeout
+		}
+	}
+
+	// runtime.KeepAlive is needed, as c is passed via native
+	// code to ioCompletionProcessor, c must remain alive
+	// until the channel read is complete.
+	runtime.KeepAlive(c)
+	return int(r.bytes), err
+}
+
+// Read reads from a file handle.
+func (f *win32File) Read(b []byte) (int, error) {
+	c, err := f.prepareIo()
+	if err != nil {
+		return 0, err
+	}
+	defer f.wg.Done()
+
+	if f.readDeadline.timedout.isSet() {
+		return 0, ErrTimeout
+	}
+
+	var bytes uint32
+	err = syscall.ReadFile(f.handle, b, &bytes, &c.o)
+	n, err := f.asyncIo(c, &f.readDeadline, bytes, err)
+	runtime.KeepAlive(b)
+
+	// Handle EOF conditions.
+	if err == nil && n == 0 && len(b) != 0 {
+		return 0, io.EOF
+	} else if err == syscall.ERROR_BROKEN_PIPE {
+		return 0, io.EOF
+	} else {
+		return n, err
+	}
+}
+
+// Write writes to a file handle.
+func (f *win32File) Write(b []byte) (int, error) {
+	c, err := f.prepareIo()
+	if err != nil {
+		return 0, err
+	}
+	defer f.wg.Done()
+
+	if f.writeDeadline.timedout.isSet() {
+		return 0, ErrTimeout
+	}
+
+	var bytes uint32
+	err = syscall.WriteFile(f.handle, b, &bytes, &c.o)
+	n, err := f.asyncIo(c, &f.writeDeadline, bytes, err)
+	runtime.KeepAlive(b)
+	return n, err
+}
+
+func (f *win32File) SetReadDeadline(deadline time.Time) error {
+	return f.readDeadline.set(deadline)
+}
+
+func (f *win32File) SetWriteDeadline(deadline time.Time) error {
+	return f.writeDeadline.set(deadline)
+}
+
+func (f *win32File) Flush() error {
+	return syscall.FlushFileBuffers(f.handle)
+}
+
+func (d *deadlineHandler) set(deadline time.Time) error {
+	d.setLock.Lock()
+	defer d.setLock.Unlock()
+
+	if d.timer != nil {
+		if !d.timer.Stop() {
+			<-d.channel
+		}
+		d.timer = nil
+	}
+	d.timedout.setFalse()
+
+	select {
+	case <-d.channel:
+		d.channelLock.Lock()
+		d.channel = make(chan struct{})
+		d.channelLock.Unlock()
+	default:
+	}
+
+	if deadline.IsZero() {
+		return nil
+	}
+
+	timeoutIO := func() {
+		d.timedout.setTrue()
+		close(d.channel)
+	}
+
+	now := time.Now()
+	duration := deadline.Sub(now)
+	if deadline.After(now) {
+		// Deadline is in the future, set a timer to wait
+		d.timer = time.AfterFunc(duration, timeoutIO)
+	} else {
+		// Deadline is in the past. Cancel all pending IO now.
+		timeoutIO()
+	}
+	return nil
+}