1 files changed, 166 insertions, 0 deletions
diff --git a/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.TypeSystem/MetadataReferenceCache.cs b/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.TypeSystem/MetadataReferenceCache.cs
new file mode 100644
index 0000000000..77d8e818eb
--- /dev/null
+++ b/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.TypeSystem/MetadataReferenceCache.cs
@@ -0,0 +1,166 @@
+//
+// MetadataReferenceCache.cs
+//
+// Author:
+//       David Karlaš <david.karlas@xamarin.com>
+//
+// Copyright (c) 2015 Xamarin, Inc (http://www.xamarin.com)
+//
+// 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.
+using System;
+using Microsoft.CodeAnalysis;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using System.IO;
+using MonoDevelop.Core;
+using System.Threading;
+
+namespace MonoDevelop.Ide.TypeSystem
+{
+	static class MetadataReferenceCache
+	{
+		static Dictionary<string, MetadataReferenceCacheItem> cache = new Dictionary<string, MetadataReferenceCacheItem> ();
+
+		public static MetadataReference LoadReference (ProjectId projectId, string path)
+		{
+			lock (cache) {
+				MetadataReferenceCacheItem result;
+				if (!cache.TryGetValue (path, out result)) {
+					result = new MetadataReferenceCacheItem (path);
+					cache.Add (path, result);
+				}
+				result.InUseBy.Add (projectId);
+				return result.Reference;
+			}
+		}
+
+		//TODO: This should be called when reference is actually removed and not on
+		//project reload because if this is only project that has this reference... Cache will be
+		//invalidated and when reload comes back in few miliseconds it will need to reload reference again
+		public static void RemoveReference (ProjectId projectId, string path)
+		{
+			lock (cache) {
+				MetadataReferenceCacheItem result;
+				if (cache.TryGetValue (path, out result)) {
+					result.InUseBy.Remove (projectId);
+					if (result.InUseBy.Count == 0) {
+						cache.Remove (path);
+					}
+				}
+			}
+		}
+
+		public static void RemoveReferences (ProjectId id)
+		{
+			lock (cache) {
+				var toRemove = new List<string> ();
+				foreach (var val in cache) {
+					val.Value.InUseBy.Remove (id);
+					if (val.Value.InUseBy.Count == 0) {
+						toRemove.Add (val.Key);
+					}
+				}
+				toRemove.ForEach ((k) => cache.Remove (k));
+			}
+		}
+
+		static Timer timer;
+
+		static MetadataReferenceCache ()
+		{
+			timer = new Timer ((o) => CheckForChanges (), null, 10000, 10000);
+		}
+
+		//TODO: Call this method when focus returns to MD or even better use FileSystemWatcher
+		public static void CheckForChanges ()
+		{
+			lock (cache) {
+				foreach (var value in cache.Values) {
+					value.CheckForChange ();
+				}
+			}
+		}
+
+		class MetadataReferenceCacheItem
+		{
+			public HashSet<ProjectId> InUseBy { get; private set; }
+
+			public MetadataReference Reference { get; private set; }
+
+			readonly string path;
+
+			DateTime timeStamp;
+
+			public MetadataReferenceCacheItem (string path)
+			{
+				this.path = path;
+				CreateNewReference ();
+				InUseBy = new HashSet<ProjectId> ();
+			}
+
+			public void CheckForChange ()
+			{
+				if (timeStamp != File.GetLastWriteTimeUtc (path)) {
+					if (Reference != null) {
+						foreach (var solution in IdeApp.Workspace.GetAllSolutions ()) {
+							var workspace = TypeSystemService.GetWorkspace (solution);
+							foreach (var projId in InUseBy) {
+								while (true) {
+									var project = workspace.CurrentSolution.GetProject (projId);
+									if (project == null)
+										break;
+									if (workspace.TryApplyChanges (project.RemoveMetadataReference (Reference).Solution))
+										break;
+								}
+							}
+						}
+					}
+					CreateNewReference ();
+					if (Reference != null) {
+						foreach (var solution in IdeApp.Workspace.GetAllSolutions ()) {
+							var workspace = TypeSystemService.GetWorkspace (solution);
+							foreach (var projId in InUseBy) {
+								while (true) {
+									var project = workspace.CurrentSolution.GetProject (projId);
+									if (project == null)
+										break;
+									if (workspace.TryApplyChanges (project.AddMetadataReference (Reference).Solution))
+										break;
+								}
+							}
+						}
+					}
+				}
+			}
+
+			readonly static DateTime NonExistentFile = new DateTime (1601, 1, 1);
+
+			void CreateNewReference ()
+			{
+				timeStamp = File.GetLastWriteTimeUtc (path);
+				if (timeStamp == NonExistentFile) {
+					Reference = null;
+				} else {
+					Reference = MetadataReference.CreateFromFile (path, MetadataReferenceProperties.Assembly);
+				}
+			}
+		}
+	}
+}
+