[VersionControl] (GIT) Speed up getting the status of a file/directory

Remove a bunch of custom logic which was used to generate the status report
for a checkout and use the built-in logic instead. This greatly speeds up
the process as the original code processed every file on disk whereas the
new code can filter out entire subtrees easily and aborts scanning as soon
as it is guaranteed that no further files will satisfy the filter (if there
is one).

6 files changed, 103 insertions, 374 deletions

diff --git a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/Makefile.am b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/Makefile.am
index cb55a46f07..e9b0e461f2 100644
--- a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/Makefile.am
+++ b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/Makefile.am
@@ -39,6 +39,7 @@ FILES =  \
 	MonoDevelop.VersionControl.Git/CredentialsDialog.cs \
 	MonoDevelop.VersionControl.Git/EditBranchDialog.cs \
 	MonoDevelop.VersionControl.Git/EditRemoteDialog.cs \
+	MonoDevelop.VersionControl.Git/FilteredStatus.cs \
 	MonoDevelop.VersionControl.Git/GitClient.cs \
 	MonoDevelop.VersionControl.Git/GitCommitDialogExtension.cs \
 	MonoDevelop.VersionControl.Git/GitCommitDialogExtensionWidget.cs \
@@ -55,7 +56,6 @@ FILES =  \
 	MonoDevelop.VersionControl.Git/MergeDialog.cs \
 	MonoDevelop.VersionControl.Git/NewStashDialog.cs \
 	MonoDevelop.VersionControl.Git/PushDialog.cs \
-	MonoDevelop.VersionControl.Git/RepositoryStatus.cs \
 	MonoDevelop.VersionControl.Git/Stash.cs \
 	MonoDevelop.VersionControl.Git/StashManagerDialog.cs \
 	MonoDevelop.VersionControl.Git/UserInfoConflictDialog.cs
diff --git a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git.csproj b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git.csproj
index efa8752a70..638d825b17 100644
--- a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git.csproj
+++ b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git.csproj
@@ -61,7 +61,6 @@
     <Compile Include="gtk-gui\MonoDevelop.VersionControl.Git.EditRemoteDialog.cs" />
     <Compile Include="gtk-gui\MonoDevelop.VersionControl.Git.MergeDialog.cs" />
     <Compile Include="MonoDevelop.VersionControl.Git\Change.cs" />
-    <Compile Include="MonoDevelop.VersionControl.Git\RepositoryStatus.cs" />
     <Compile Include="MonoDevelop.VersionControl.Git\MergeDialog.cs" />
     <Compile Include="MonoDevelop.VersionControl.Git\Stash.cs" />
     <Compile Include="MonoDevelop.VersionControl.Git\GitUtil.cs" />
@@ -79,6 +78,7 @@
     <Compile Include="gtk-gui\MonoDevelop.VersionControl.Git.GitCommitDialogExtensionWidget.cs" />
     <Compile Include="MonoDevelop.VersionControl.Git\GitCommitDialogExtension.cs" />
     <Compile Include="MonoDevelop.VersionControl.Git\GitSupportFeature.cs" />
+    <Compile Include="MonoDevelop.VersionControl.Git\FilteredStatus.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\core\MonoDevelop.Core\MonoDevelop.Core.csproj">
diff --git a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/FilteredStatus.cs b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/FilteredStatus.cs
new file mode 100644
index 0000000000..7099028d12
--- /dev/null
+++ b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/FilteredStatus.cs
@@ -0,0 +1,80 @@
+// 
+// SpecificStatus.cs
+//  
+// Author:
+//       Alan McGovern <alan@xamarin.com>
+// 
+// Copyright (c) 2012 Xamarin Inc.
+// 
+// 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 System.Collections.Generic;
+using System.Linq;
+
+using NGit;
+using NGit.Treewalk;
+using NGit.Treewalk.Filter;
+
+namespace MonoDevelop.VersionControl.Git
+{
+	class FilteredStatus : NGit.Api.StatusCommand
+	{
+		WorkingTreeIterator iter;
+
+		IEnumerable<string> Files {
+			get; set;
+		}
+		
+		public FilteredStatus (NGit.Repository repository)
+			: base (repository)
+		{
+			
+		}
+		
+		public FilteredStatus (NGit.Repository repository, IEnumerable<string> files)
+			: base (repository)
+		{
+			Files = files;
+		}
+		
+		public override NGit.Api.StatusCommand SetWorkingTreeIt (WorkingTreeIterator workingTreeIt)
+		{
+			iter = workingTreeIt;
+			return this;
+		}
+		
+		public override NGit.Api.Status Call ()
+		{
+			if (iter == null)
+				iter = new FileTreeIterator(repo);
+			
+			IndexDiff diff = new IndexDiff(repo, Constants.HEAD, iter);
+			if (Files != null) {
+				var filters = Files.Where (f => f != ".").ToArray ();
+				if (filters.Length > 0)
+					diff.SetFilter (PathFilterGroup.CreateFromStrings (filters));
+			}
+			
+			diff.Diff ();
+			return new NGit.Api.Status(diff);
+		}
+	}
+}
+
diff --git a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitRepository.cs b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitRepository.cs
index 2850a1f95c..45ade91b23 100644
--- a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitRepository.cs
+++ b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitRepository.cs
@@ -266,12 +266,18 @@ namespace MonoDevelop.VersionControl.Git
 			else
 				rev = null;
 			
-			RepositoryStatus status;
-			if (localFileNames != null)
-				status = GitUtil.GetFileStatus (repo, localFileNames);
-			else
-				status = GitUtil.GetDirectoryStatus (repo, localDirectory, recursive);
-			
+			IEnumerable<string> paths;
+			if (localFileNames == null) {
+				if (recursive)
+					paths = new [] { (string) localDirectory };
+				else
+					paths = Directory.GetFiles (localDirectory);
+			} else {
+				paths = localFileNames.Select (f => (string)f);
+			}
+			paths = paths.Select (f => ToGitPath (f));
+
+			var status = new FilteredStatus (repo, paths).Call (); 
 			HashSet<string> added = new HashSet<string> ();
 			Action<IEnumerable<string>, VersionStatus> AddFiles = delegate(IEnumerable<string> files, VersionStatus fstatus) {
 				foreach (string file in files) {
@@ -284,13 +290,14 @@ namespace MonoDevelop.VersionControl.Git
 				}
 			};
 			
-			AddFiles (status.Added, VersionStatus.Versioned | VersionStatus.ScheduledAdd);
-			AddFiles (status.Modified, VersionStatus.Versioned | VersionStatus.Modified);
-			AddFiles (status.Removed, VersionStatus.Versioned | VersionStatus.ScheduledDelete);
-			AddFiles (status.Missing, VersionStatus.Versioned | VersionStatus.ScheduledDelete);
-			AddFiles (status.MergeConflict, VersionStatus.Versioned | VersionStatus.Conflicted);
-			AddFiles (status.Untracked, VersionStatus.Unversioned);
-			
+			AddFiles (status.GetAdded (), VersionStatus.Versioned | VersionStatus.ScheduledAdd);
+			AddFiles (status.GetChanged (), VersionStatus.Versioned | VersionStatus.Modified);
+			AddFiles (status.GetModified (), VersionStatus.Versioned | VersionStatus.Modified);
+			AddFiles (status.GetRemoved (), VersionStatus.Versioned | VersionStatus.ScheduledDelete);
+			AddFiles (status.GetMissing (), VersionStatus.Versioned | VersionStatus.ScheduledDelete);
+			AddFiles (status.GetConflicting (), VersionStatus.Versioned | VersionStatus.Conflicted);
+			AddFiles (status.GetUntracked (), VersionStatus.Unversioned);
+
 			// Existing files for which git did not report an status are supposed to be tracked
 			foreach (FilePath file in existingFiles) {
 				VersionInfo vi = new VersionInfo (file, "", false, VersionStatus.Versioned, rev, VersionStatus.Versioned, null);
diff --git a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitUtil.cs b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitUtil.cs
index 8f9912e4ec..367faeac92 100644
--- a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitUtil.cs
+++ b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/GitUtil.cs
@@ -164,17 +164,7 @@ namespace MonoDevelop.VersionControl.Git
 				}
 			}
 		}
-		
-		public static RepositoryStatus GetDirectoryStatus (NGit.Repository repo, string dir, bool recursive)
-		{
-			return new RepositoryStatus (repo, null, repo.ToGitPath (dir), recursive);
-		}
-		
-		public static RepositoryStatus GetFileStatus (NGit.Repository repo, IEnumerable<FilePath> fileNames)
-		{
-			return new RepositoryStatus (repo, repo.ToGitPath (fileNames), null, false);
-		}
-		
+
 		public static ObjectId CreateCommit (NGit.Repository rep, string message, IList<ObjectId> parents, ObjectId indexTreeId, PersonIdent author, PersonIdent committer)
 		{
 			try {
diff --git a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/RepositoryStatus.cs b/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/RepositoryStatus.cs
deleted file mode 100644
index 43d216dbba..0000000000
--- a/main/src/addins/VersionControl/MonoDevelop.VersionControl.Git/MonoDevelop.VersionControl.Git/RepositoryStatus.cs
+++ /dev/null
@@ -1,348 +0,0 @@
-/*
- * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
- * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
- * Copyright (C) 2010, Henon <meinrad.recheis@gmail.com>
- *
- * 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 the Git Development Community 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.
- */
-
-using System;
-using System.Linq;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.IO;
-using NGit;
-using NGit.Revwalk;
-using NGit.Treewalk;
-using NGit.Dircache;
-using NGit.Treewalk.Filter;
-
-namespace MonoDevelop.VersionControl.Git
-{
-	class SpecificStatus : NGit.Api.StatusCommand
-	{
-		WorkingTreeIterator iter;
-		IEnumerable<string> Files {
-			get; set;
-		}
-		
-		public SpecificStatus (NGit.Repository repository)
-			: base (repository)
-		{
-		}
-		
-		public SpecificStatus (NGit.Repository repository, IEnumerable<string> files)
-			: base (repository)
-		{
-			Files = files;
-		}
-		
-		public override NGit.Api.StatusCommand SetWorkingTreeIt (WorkingTreeIterator workingTreeIt)
-		{
-			iter = workingTreeIt;
-			return this;
-		}
-		
-		public override NGit.Api.Status Call ()
-		{
-			if (iter == null)
-				iter = new FileTreeIterator(repo);
-			
-			IndexDiff diff = new IndexDiff(repo, Constants.HEAD, iter);
-			if (Files != null) {
-				var filters = Files.Select (PathFilter.Create).ToArray ();
-				if (filters.Length > 1)
-					diff.SetFilter (OrTreeFilter.Create (filters));
-				else
-					diff.SetFilter (filters [0]);
-			}
-			
-			diff.Diff ();
-			return new NGit.Api.Status(diff);
-		}
-	}
-	
-	public class RepositoryStatus
-	{
-		private string _root_path;
-		private bool _recursive;
-		private IEnumerable<string> _file_paths;
-		private bool changesExist;
-
-		internal RepositoryStatus(NGit.Repository repository, IEnumerable<string> singleFiles, string rootDir, bool recursive)
-		{
-			Repository = repository;
-			_root_path = rootDir;
-			_recursive = recursive;
-			_file_paths = singleFiles;
-			Update();
-		}
-
-		public NGit.Repository Repository
-		{
-			get;
-			private set;
-		}
-		
-		public bool ChangesExist {
-			get { return changesExist; }
-		}
-		
-		/// <summary>
-		/// List of files added to the index, which are not in the current commit
-		/// </summary>
-		public HashSet<string> Added { get; private set; }
-
-		/// <summary>
-		/// List of files added to the index, which are already in the current commit with different content
-		/// </summary>
-		public HashSet<string> Staged { get; private set; }
-
-		/// <summary>
-		/// List of files removed from the index but are existent in the current commit
-		/// </summary>
-		public HashSet<string> Removed { get; private set; }
-
-		/// <summary>
-		/// List of files existent in the index but are missing in the working directory
-		/// </summary>
-		public HashSet<string> Missing { get; private set; }
-
-		/// <summary>
-		/// List of files with unstaged modifications. A file may be modified and staged at the same time if it has been modified after adding.
-		/// </summary>
-		public HashSet<string> Modified { get; private set; }
-
-		/// <summary>
-		/// List of files existing in the working directory but are neither tracked in the index nor in the current commit.
-		/// </summary>
-		public HashSet<string> Untracked { get; private set; }
-
-		/// <summary>
-		/// List of files with staged modifications that conflict.
-		/// </summary>
-		public HashSet<string> MergeConflict { get; private set; }
-
-		///// <summary>
-		///// Returns the number of files checked into the git repository
-		///// </summary>
-		//public int IndexSize { get { return _index.Members.Count; } }
-
-		public bool AnyDifferences { get; private set; }
-
-		/// <summary>
-		/// Recalculates the status
-		/// </summary>
-		public void Update()
-		{
-			AnyDifferences = false;
-			Added = new HashSet<string>();
-			Staged = new HashSet<string>();
-			Removed = new HashSet<string>();
-			Missing = new HashSet<string>();
-			Modified = new HashSet<string>();
-			Untracked = new HashSet<string>();
-			MergeConflict = new HashSet<string>();
-			
-			if (_file_paths != null)
-				UpdateSingleFiles (_file_paths.ToList ());
-			else if (_recursive)
-				UpdateDirectory (new string[] { _root_path }, true);
-			else
-				UpdateDirectory (new string[] { _root_path }, false);
-		}
-		
-		void UpdateSingleFiles (List<string> singleFiles)
-		{
-			// NGIT HACK: We verify that all the files listed in the result of
-			// the GitStatus call are actually in the list of files we're interested
-			// in. This is because NGit cannot properly filter the git tree and
-			// incorrectly includes extra directories. See bug #
-			var status = new SpecificStatus (Repository, singleFiles).Call ();
-
-			foreach (var v in status.GetAdded ())
-				if (singleFiles.Contains (v))
-					Added.Add (v);
-
-			foreach (var v in status.GetChanged ())
-				if (singleFiles.Contains (v))
-					Modified.Add (v);
-
-			foreach (var v in status.GetConflicting ())
-				if (singleFiles.Contains (v))
-					MergeConflict.Add (v);
-
-			foreach (var v in status.GetMissing ())
-				if (singleFiles.Contains (v))
-					Missing.Add (v);
-
-			foreach (var v in status.GetModified ())
-				if (singleFiles.Contains (v))
-					Modified.Add (v);
-
-			foreach (var v in status.GetRemoved ())
-				if (singleFiles.Contains (v))
-					Removed.Add (v);
-			
-			foreach (var v in status.GetUntracked ())
-				if (singleFiles.Contains (v))
-					Untracked.Add (v);
-		}
-
-		/// <summary>
-		/// Run the diff operation. Until this is called, all lists will be empty
-		/// </summary>
-		/// <returns>true if anything is different between index, tree, and workdir</returns>
-		private void UpdateDirectory (IEnumerable<string> paths, bool recursive)
-		{
-			RevWalk rw = new RevWalk (Repository);
-			ObjectId id = Repository.Resolve (Constants.HEAD);
-			var commit = id != null ? rw.ParseCommit (id) : null;
-			
-			TreeWalk treeWalk = new TreeWalk (Repository);
-			treeWalk.Reset ();
-			treeWalk.Recursive = recursive;
-
-			if (commit != null)
-				treeWalk.AddTree (commit.Tree);
-			else
-				treeWalk.AddTree (new EmptyTreeIterator());
-			
-			DirCache dc = Repository.ReadDirCache ();
-			treeWalk.AddTree (new DirCacheIterator (dc));
-			
-			FileTreeIterator workTree = new FileTreeIterator (Repository.WorkTree, Repository.FileSystem, WorkingTreeOptions.KEY.Parse(Repository.GetConfig()));
-			treeWalk.AddTree (workTree);
-
-			List<TreeFilter> filters = new List<TreeFilter> ();
-			filters.Add (new SkipWorkTreeFilter(1));
-			
-			var pathFilters = paths.Where (p => p != ".").Select (p => PathFilter.Create (p)).ToArray ();
-			if (pathFilters.Length > 1) {
-				filters.Add (OrTreeFilter.Create (pathFilters)); // Use an OR to join all path filters
-			} else if (pathFilters.Length == 1)
-				filters.Add (pathFilters[0]);
-
-			if (filters.Count > 1)
-				treeWalk.Filter = AndTreeFilter.Create(filters);
-			else
-				treeWalk.Filter = filters[0];
-			
-			while (treeWalk.Next())
-			{
-				AbstractTreeIterator treeIterator = treeWalk.GetTree<AbstractTreeIterator>(0);
-				DirCacheIterator dirCacheIterator = treeWalk.GetTree<DirCacheIterator>(1);
-				WorkingTreeIterator workingTreeIterator = treeWalk.GetTree<WorkingTreeIterator>(2);
-				NGit.FileMode fileModeTree = treeWalk.GetFileMode(0);
-				
-				if (treeWalk.IsSubtree) {
-					treeWalk.EnterSubtree ();
-					continue;
-				}
-				
-				int stage = dirCacheIterator != null ? dirCacheIterator.GetDirCacheEntry ().Stage : 0;
-				if (stage > 1)
-					continue;
-				else if (stage == 1) {
-					MergeConflict.Add(dirCacheIterator.EntryPathString);
-					changesExist = true;
-					continue;
-				}
-				
-				if (treeIterator != null)
-				{
-					if (dirCacheIterator != null)
-					{
-						if (!treeIterator.EntryObjectId.Equals(dirCacheIterator.EntryObjectId))
-						{
-							// in repo, in index, content diff => changed
-							Modified.Add(dirCacheIterator.EntryPathString);
-							changesExist = true;
-						}
-					}
-					else
-					{
-						// in repo, not in index => removed
-						if (!fileModeTree.Equals(NGit.FileMode.TYPE_TREE))
-						{
-							Removed.Add(treeIterator.EntryPathString);
-							changesExist = true;
-						}
-					}
-				}
-				else
-				{
-					if (dirCacheIterator != null)
-					{
-						// not in repo, in index => added
-						Added.Add(dirCacheIterator.EntryPathString);
-						changesExist = true;
-					}
-					else
-					{
-						// not in repo, not in index => untracked
-						if (workingTreeIterator != null && !workingTreeIterator.IsEntryIgnored())
-						{
-							Untracked.Add(workingTreeIterator.EntryPathString);
-							changesExist = true;
-						}
-					}
-				}
-				if (dirCacheIterator != null)
-				{
-					if (workingTreeIterator == null)
-					{
-						// in index, not in workdir => missing
-						Missing.Add(dirCacheIterator.EntryPathString);
-						changesExist = true;
-					}
-					else
-					{
-						// Workaround to file time resolution issues
-						long itime = dirCacheIterator.GetDirCacheEntry ().LastModified;
-						long ftime = workingTreeIterator.GetEntryLastModified ();
-						if (itime / 1000 != ftime / 1000) {
-							if (!dirCacheIterator.IdEqual(workingTreeIterator))
-							{
-								// in index, in workdir, content differs => modified
-								Modified.Add(dirCacheIterator.EntryPathString);
-								changesExist = true;
-							}
-						}
-					}
-				}
-			}
-		}
-	}
-}