Cache objects from database in memory to improve performance (#151)

* IGDB objects are now cached in memory

* Completed caching of PlatformMaps

gaseous-server/Classes/Metadata/Storage.cs

@@ -4,6 +4,7 @@ using System.Reflection;
 using gaseous_tools;
 using IGDB;
 using IGDB.Models;
+using Microsoft.Extensions.Caching.Memory;
 
 namespace gaseous_server.Classes.Metadata
 {
@@ -16,14 +17,32 @@ namespace gaseous_server.Classes.Metadata
 			Expired
 		}
 
+        private static Dictionary<string, MemoryCacheObject> ObjectCache = new Dictionary<string, MemoryCacheObject>();
+
 		public static CacheStatus GetCacheStatus(string Endpoint, string Slug)
 		{
-			return _GetCacheStatus(Endpoint, "slug", Slug);
+            CacheClean();
+            if (ObjectCache.ContainsKey(Endpoint + Slug))
+            {
+                return CacheStatus.Current;
+            }
+            else
+            {
+			    return _GetCacheStatus(Endpoint, "slug", Slug);
+            }
 		}
 
         public static CacheStatus GetCacheStatus(string Endpoint, long Id)
         {
-			return _GetCacheStatus(Endpoint, "id", Id);
+            CacheClean();
+            if (ObjectCache.ContainsKey(Endpoint + Id))
+            {
+                return CacheStatus.Current;
+            }
+            else
+			{
+                return _GetCacheStatus(Endpoint, "id", Id);
+            }
         }
 
         public static CacheStatus GetCacheStatus(DataRow Row)
@@ -164,6 +183,21 @@ namespace gaseous_server.Classes.Metadata
 		{
             string Endpoint = EndpointType.GetType().Name;
 
+            if (ObjectCache.ContainsKey(Endpoint + SearchValue))
+            {
+                MemoryCacheObject cacheObject = ObjectCache[Endpoint + SearchValue];
+                if (cacheObject.ExpiryTime < DateTime.UtcNow)
+                {
+                    // object has expired, remove it
+                    ObjectCache.Remove(Endpoint + SearchValue);
+                }
+                else
+                {
+                    // object is valid, return it
+                    return (T)cacheObject.Object;
+                }
+            }
+
             Database db = new gaseous_tools.Database(Database.databaseType.MySql, Config.DatabaseConfiguration.ConnectionString);
 
             string sql = "SELECT * FROM " + Endpoint + " WHERE " + SearchField + " = @" + SearchField;
@@ -181,7 +215,11 @@ namespace gaseous_server.Classes.Metadata
             else
             {
 				DataRow dataRow = dt.Rows[0];
-                return BuildCacheObject<T>(EndpointType, dataRow);
+                object returnObject = BuildCacheObject<T>(EndpointType, dataRow);
+                ObjectCache.Add(Endpoint + SearchValue, new MemoryCacheObject{
+                    Object = returnObject
+                });
+                return (T)returnObject;
             }
         }
 
@@ -380,6 +418,31 @@ namespace gaseous_server.Classes.Metadata
 
             return EndpointType;
         }
+
+        private static void CacheClean()
+        {
+            Dictionary<string, MemoryCacheObject> workCache = ObjectCache;
+            foreach (KeyValuePair<string, MemoryCacheObject> objectCache in workCache)
+            {
+                if (objectCache.Value.ExpiryTime < DateTime.UtcNow)
+                {
+                    ObjectCache.Remove(objectCache.Key);
+                }
+            }
+        }
+
+        private class MemoryCacheObject
+        {
+            public object Object { get; set; }
+            public DateTime CreationTime { get; } = DateTime.UtcNow;
+            public DateTime ExpiryTime 
+            {
+                get
+                {
+                    return CreationTime.AddMinutes(60);
+                }
+            }
+        }
     }
 }
 

gaseous-server/Models/PlatformMapping.cs

@@ -15,6 +15,8 @@ namespace gaseous_server.Models
 {
 	public class PlatformMapping
 	{
+        private static Dictionary<string, PlatformMapItem> PlatformMapCache = new Dictionary<string, PlatformMapItem>();
+
         /// <summary>
         /// Updates the platform map from the embedded platform map resource
         /// </summary>
@@ -98,7 +100,15 @@ namespace gaseous_server.Models
                 List<PlatformMapItem> platformMaps = new List<PlatformMapItem>();
                 foreach (DataRow row in data.Rows)
                 {
-                    platformMaps.Add(BuildPlatformMapItem(row));
+                    long mapId = (long)row["Id"];
+                    if (PlatformMapCache.ContainsKey(mapId.ToString()))
+                    {
+                        platformMaps.Add(PlatformMapCache[mapId.ToString()]);
+                    }
+                    else
+                    {
+                        platformMaps.Add(BuildPlatformMapItem(row));
+                    }
                 }
 
                 platformMaps.Sort((x, y) => x.IGDBName.CompareTo(y.IGDBName));
@@ -109,23 +119,30 @@ namespace gaseous_server.Models
 
         public static PlatformMapItem GetPlatformMap(long Id)
         {
-            Database db = new gaseous_tools.Database(Database.databaseType.MySql, Config.DatabaseConfiguration.ConnectionString);
+            if (PlatformMapCache.ContainsKey(Id.ToString()))
-            string sql = "SELECT * FROM PlatformMap WHERE Id = @Id";
-            Dictionary<string, object> dbDict = new Dictionary<string, object>();
-            dbDict.Add("Id", Id);
-            DataTable data = db.ExecuteCMD(sql, dbDict);
-
-            if (data.Rows.Count > 0)
             {
-                PlatformMapItem platformMap = BuildPlatformMapItem(data.Rows[0]);
+                return PlatformMapCache[Id.ToString()];
-
-                return platformMap;
             }
             else
             {
-                Exception exception = new Exception("Platform Map Id " + Id + " does not exist.");
+                Database db = new gaseous_tools.Database(Database.databaseType.MySql, Config.DatabaseConfiguration.ConnectionString);
-                Logging.Log(Logging.LogType.Critical, "Platform Map", "Platform Map Id " + Id + " does not exist.", exception);
+                string sql = "SELECT * FROM PlatformMap WHERE Id = @Id";
-                throw exception;
+                Dictionary<string, object> dbDict = new Dictionary<string, object>();
+                dbDict.Add("Id", Id);
+                DataTable data = db.ExecuteCMD(sql, dbDict);
+
+                if (data.Rows.Count > 0)
+                {
+                    PlatformMapItem platformMap = BuildPlatformMapItem(data.Rows[0]);
+
+                    return platformMap;
+                }
+                else
+                {
+                    Exception exception = new Exception("Platform Map Id " + Id + " does not exist.");
+                    Logging.Log(Logging.LogType.Critical, "Platform Map", "Platform Map Id " + Id + " does not exist.", exception);
+                    throw exception;
+                }
             }
         }
 
@@ -218,6 +235,11 @@ namespace gaseous_server.Models
                     db.ExecuteCMD(sql, dbDict);
                 }
             }
+
+            if (PlatformMapCache.ContainsKey(item.IGDBId.ToString()))
+            {
+                PlatformMapCache.Remove(item.IGDBId.ToString());
+            }
         }
 
         static PlatformMapItem BuildPlatformMapItem(DataRow row)
@@ -321,6 +343,15 @@ namespace gaseous_server.Models
             };
             mapItem.Bios = bioss;
             
+            if (PlatformMapCache.ContainsKey(IGDBId.ToString()))
+            {
+                PlatformMapCache[IGDBId.ToString()] = mapItem;
+            }
+            else
+            {
+                PlatformMapCache.Add(IGDBId.ToString(), mapItem);
+            }
+
             return mapItem;
         }