Refactor remaining sysinfoapi calls into header package

Signed-off-by: Ben Ridley <benridley29@gmail.com>

collector/cs.go

@@ -3,8 +3,9 @@
 package collector
 
 import (
+	"github.com/prometheus-community/windows_exporter/headers/sysinfoapi"
 	"github.com/prometheus-community/windows_exporter/log"
-	"github.com/prometheus-community/windows_exporter/sysinfoapi"
+
 	"github.com/prometheus/client_golang/prometheus"
 )
 
@@ -59,9 +60,11 @@ func (c *CSCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) e
 }
 
 func (c *CSCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
-	cs := sysinfoapi.GetNumLogicalProcessors()
+	// Get systeminfo for number of processors
+	systemInfo := sysinfoapi.GetSystemInfo()
 
-	pm, err := sysinfoapi.GetPhysicalMemory()
+	// Get memory status for physical memory
+	mem, err := sysinfoapi.GlobalMemoryStatusEx()
 	if err != nil {
 		return nil, err
 	}
@@ -69,13 +72,13 @@ func (c *CSCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, er
 	ch <- prometheus.MustNewConstMetric(
 		c.LogicalProcessors,
 		prometheus.GaugeValue,
-		float64(cs),
+		float64(systemInfo.DwNumberOfProcessors),
 	)
 
 	ch <- prometheus.MustNewConstMetric(
 		c.PhysicalMemoryBytes,
 		prometheus.GaugeValue,
-		float64(pm),
+		float64(mem.UllTotalPhys),
 	)
 
 	hostname, err := sysinfoapi.GetComputerName(sysinfoapi.ComputerNameDNSHostname)

headers/sysinfoapi/sysinfoapi.go

@@ -1,6 +1,7 @@
 package sysinfoapi
 
 import (
+	"unicode/utf16"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
@@ -20,10 +21,49 @@ type MemoryStatusEx struct {
 	UllAvailExtendedVirtual uint64
 }
 
+// wProcessorArchitecture is a wrapper for the union found in LP_SYSTEM_INFO
+// https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info
+type wProcessorArchitecture struct {
+	WReserved              uint16
+	WProcessorArchitecture uint16
+}
+
+// LpSystemInfo is a wrapper for LPSYSTEM_INFO
+// https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info
+type LpSystemInfo struct {
+	Arch                        wProcessorArchitecture
+	DwPageSize                  uint32
+	LpMinimumApplicationAddress *byte
+	LpMaximumApplicationAddress *byte
+	DwActiveProcessorMask       *uint32
+	DwNumberOfProcessors        uint32
+	DwProcessorType             uint32
+	DwAllocationGranularity     uint32
+	WProcessorLevel             uint16
+	WProcessorRevision          uint16
+}
+
+// WinComputerNameFormat is a wrapper for COMPUTER_NAME_FORMAT
+type WinComputerNameFormat int
+
+// Definitions for WinComputerNameFormat constants
+const (
+	ComputerNameNetBIOS WinComputerNameFormat = iota
+	ComputerNameDNSHostname
+	ComputerNameDNSDomain
+	ComputerNameDNSFullyQualified
+	ComputerNamePhysicalNetBIOS
+	ComputerNamePhysicalDNSHostname
+	ComputerNamePhysicalDNSDomain
+	ComputerNamePhysicalDNSFullyQualified
+	ComputerNameMax
+)
+
 var (
 	kernel32                 = windows.NewLazySystemDLL("kernel32.dll")
 	procGetSystemInfo        = kernel32.NewProc("GetSystemInfo")
 	procGlobalMemoryStatusEx = kernel32.NewProc("GlobalMemoryStatusEx")
+	procGetComputerNameExW   = kernel32.NewProc("GetComputerNameExW")
 )
 
 // GlobalMemoryStatusEx retrieves information about the system's current usage of both physical and virtual memory.
@@ -41,3 +81,28 @@ func GlobalMemoryStatusEx() (MemoryStatusEx, error) {
 
 	return mse, nil
 }
+
+// GetSystemInfo wraps the GetSystemInfo function from sysinfoapi
+// https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsysteminfo
+func GetSystemInfo() LpSystemInfo {
+	var info LpSystemInfo
+	pInfo := uintptr(unsafe.Pointer(&info))
+	procGetSystemInfo.Call(pInfo)
+	return info
+}
+
+// GetComputerName wraps the GetComputerNameW function in a more Go-like way
+// https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getcomputernamew
+func GetComputerName(f WinComputerNameFormat) (string, error) {
+	// 1kb buffer to accept computer name. This should be more than enough as the maximum size
+	// returned is the max length of a DNS name, which this author believes is 253 characters.
+	size := 1024
+	var buffer [4096]uint16
+	r1, _, err := procGetComputerNameExW.Call(uintptr(f), uintptr(unsafe.Pointer(&buffer)), uintptr(unsafe.Pointer(&size)))
+	if r1 == 0 {
+		return "", err
+	}
+	bytes := buffer[0:size]
+	out := utf16.Decode(bytes)
+	return string(out), nil
+}

sysinfoapi/sysinfoapi.go

@@ -1,112 +0,0 @@
-// Copyright 2020 Prometheus Team
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package sysinfoapi wraps some WinAPI sysinfoapi functions used by the exporter to produce metrics.
-// It is fairly opinionated for the exporter's internal use, and is not intended to be a
-// generic wrapper for the WinAPI's sysinfoapi.
-package sysinfoapi
-
-import (
-	"unicode/utf16"
-	"unsafe"
-
-	"golang.org/x/sys/windows"
-)
-
-// WinProcInfo is a wrapper for
-type WinProcInfo struct {
-	WReserved              uint16
-	WProcessorArchitecture uint16
-}
-
-// WinSystemInfo is a wrapper for LPSYSTEM_INFO
-type WinSystemInfo struct {
-	Arch                        WinProcInfo
-	DwPageSize                  uint32
-	LpMinimumApplicationAddress *byte
-	LpMaximumApplicationAddress *byte
-	DwActiveProcessorMask       *uint32
-	DwNumberOfProcessors        uint32
-	DwProcessorType             uint32
-	DwAllocationGranularity     uint32
-	WProcessorLevel             uint16
-	WProcessorRevision          uint16
-}
-
-// WinComputerNameFormat is a wrapper for COMPUTER_NAME_FORMAT
-type WinComputerNameFormat int
-
-// Definitions for WinComputerNameFormat constants
-const (
-	ComputerNameNetBIOS WinComputerNameFormat = iota
-	ComputerNameDNSHostname
-	ComputerNameDNSDomain
-	ComputerNameDNSFullyQualified
-	ComputerNamePhysicalNetBIOS
-	ComputerNamePhysicalDNSHostname
-	ComputerNamePhysicalDNSDomain
-	ComputerNamePhysicalDNSFullyQualified
-	ComputerNameMax
-)
-
-// WinMemoryStatus is a wrapper for LPMEMORYSTATUSEX
-type WinMemoryStatus struct {
-	dwLength                uint32
-	dwMemoryLoad            uint32
-	ullTotalPhys            uint64
-	ullAvailPhys            uint64
-	ullTotalPageFile        uint64
-	ullAvailPageFile        uint64
-	ullTotalVirtual         uint64
-	ullAvailVirtual         uint64
-	ullAvailExtendedVirtual uint64
-}
-
-var (
-	kernel32                 = windows.NewLazySystemDLL("kernel32.dll")
-	procGetSystemInfo        = kernel32.NewProc("GetSystemInfo")
-	procGlobalMemoryStatusEx = kernel32.NewProc("GlobalMemoryStatusEx")
-	procGetComputerNameExW   = kernel32.NewProc("GetComputerNameExW")
-)
-
-// GetNumLogicalProcessors returns the number of logical processes provided by sysinfoapi's GetSystemInfo function.
-func GetNumLogicalProcessors() int {
-	var sysInfo WinSystemInfo
-	pInfo := uintptr(unsafe.Pointer(&sysInfo))
-	procGetSystemInfo.Call(pInfo)
-	return int(sysInfo.DwNumberOfProcessors)
-}
-
-// GetPhysicalMemory returns the system's installed physical memory provided by sysinfoapi's GlobalMemoryStatusEx function.
-func GetPhysicalMemory() (int, error) {
-	var wm WinMemoryStatus
-	wm.dwLength = (uint32)(unsafe.Sizeof(wm))
-	r1, _, err := procGlobalMemoryStatusEx.Call(uintptr(unsafe.Pointer(&wm)))
-	if r1 != 1 {
-		return 0, err
-	}
-	return int(wm.ullTotalPhys), nil
-}
-
-// GetComputerName provides the requested computer name provided by sysinfoapi's GetComputerNameEx function.
-func GetComputerName(f WinComputerNameFormat) (string, error) {
-	size := 4096
-	var buffer [4096]uint16
-	r1, _, err := procGetComputerNameExW.Call(uintptr(f), uintptr(unsafe.Pointer(&buffer)), uintptr(unsafe.Pointer(&size)))
-	if r1 == 0 {
-		return "", err
-	}
-	bytes := buffer[0:size]
-	out := utf16.Decode(bytes)
-	return string(out), nil
-}