Merge pull request #1897 from tyrielv/tyrielv/avoid-git-config-process

Replace some git config calls with libgit2

Author: tyrielv

GVFS/FastFetch/FastFetchLibGit2Repo.cs

@@ -18,7 +18,7 @@ public FastFetchLibGit2Repo(ITracer tracer, string repoPath)
         public virtual bool TryCopyBlobToFile(string sha, IEnumerable<PathWithMode> destinations, out long bytesWritten)
         {
             IntPtr objHandle;
-            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.SuccessCode)
+            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.ResultCode.Success)
             {
                 bytesWritten = 0;
                 EventMetadata metadata = new EventMetadata();

GVFS/GVFS.Common/Enlistment.cs

@@ -109,31 +109,5 @@ public virtual GitProcess CreateGitProcess()
         {
             return new GitProcess(this);
         }
-
-        public bool GetTrustPackIndexesConfig()
-        {
-            var gitProcess = this.CreateGitProcess();
-            bool trustPackIndexes = true;
-            if (gitProcess.TryGetFromConfig(GVFSConstants.GitConfig.TrustPackIndexes, forceOutsideEnlistment: false, out var valueString)
-                && bool.TryParse(valueString, out var trustPackIndexesConfig))
-            {
-                trustPackIndexes = trustPackIndexesConfig;
-            }
-
-            return trustPackIndexes;
-        }
-
-        public bool GetStatusHydrationConfig()
-        {
-            var gitProcess = this.CreateGitProcess();
-
-            if (gitProcess.TryGetFromConfig(GVFSConstants.GitConfig.ShowHydrationStatus, forceOutsideEnlistment: false, out var valueString)
-                && bool.TryParse(valueString, out var statusHydrationConfig))
-            {
-                return statusHydrationConfig;
-            }
-
-            return GVFSConstants.GitConfig.ShowHydrationStatusDefault;
-        }
     }
 }

GVFS/GVFS.Common/GVFSConstants.cs

@@ -42,6 +42,7 @@ public static class GitConfig
             /* Intended to be a temporary config to allow testing of distrusting pack indexes from cache server
              * before it is enabled by default. */
             public const string TrustPackIndexes = GVFSPrefix + "trust-pack-indexes";
+            public const bool TrustPackIndexesDefault = true;
 
             public const string ShowHydrationStatus = GVFSPrefix + "show-hydration-status";
             public const bool ShowHydrationStatusDefault = false;

GVFS/GVFS.Common/Git/GitObjects.cs

@@ -153,7 +153,7 @@ public virtual void DeleteTemporaryFiles()
             }
         }
 
-        public virtual bool TryDownloadPrefetchPacks(GitProcess gitProcess, long latestTimestamp, out List<string> packIndexes)
+        public virtual bool TryDownloadPrefetchPacks(GitProcess gitProcess, long latestTimestamp, bool trustPackIndexes, out List<string> packIndexes)
         {
             EventMetadata metadata = CreateEventMetadata();
             metadata.Add("latestTimestamp", latestTimestamp);
@@ -166,7 +166,6 @@ public virtual bool TryDownloadPrefetchPacks(GitProcess gitProcess, long latestT
                  * pack file and an index file that do not match.
                  * Eventually we will make this the default, but it has a high performance cost for the first prefetch after
                  * cloning a large repository, so it must be explicitly enabled for now. */
-                bool trustPackIndexes = this.Enlistment.GetTrustPackIndexesConfig();
                 metadata.Add("trustPackIndexes", trustPackIndexes);
 
                 long requestId = HttpRequestor.GetNewRequestId();

GVFS/GVFS.Common/Git/GitRepo.cs

@@ -51,6 +51,11 @@ public GVFSLock GVFSLock
             private set;
         }
 
+        internal LibGit2RepoInvoker LibGit2RepoInvoker
+        {
+            get { return this.libgit2RepoInvoker; }
+        }
+
         public void CloseActiveRepo()
         {
             this.libgit2RepoInvoker?.DisposeSharedRepo();

GVFS/GVFS.Common/Git/LibGit2Exception.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace GVFS.Common.Git
+{
+    public class LibGit2Exception : Exception
+    {
+        public LibGit2Exception(string message) : base(message)
+        {
+        }
+
+        public LibGit2Exception(string message, Exception innerException) : base(message, innerException)
+        {
+        }
+    }
+}

GVFS/GVFS.Common/Git/LibGit2Repo.cs

@@ -17,7 +17,7 @@ public LibGit2Repo(ITracer tracer, string repoPath)
             Native.Init();
 
             IntPtr repoHandle;
-            if (Native.Repo.Open(out repoHandle, repoPath) != Native.SuccessCode)
+            if (Native.Repo.Open(out repoHandle, repoPath) != Native.ResultCode.Success)
             {
                 string reason = Native.GetLastError();
                 string message = "Couldn't open repo at " + repoPath + ": " + reason;
@@ -45,7 +45,7 @@ protected LibGit2Repo()
         public Native.ObjectTypes? GetObjectType(string sha)
         {
             IntPtr objHandle;
-            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.SuccessCode)
+            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.ResultCode.Success)
             {
                 return null;
             }
@@ -63,7 +63,7 @@ protected LibGit2Repo()
         public virtual string GetTreeSha(string commitish)
         {
             IntPtr objHandle;
-            if (Native.RevParseSingle(out objHandle, this.RepoHandle, commitish) != Native.SuccessCode)
+            if (Native.RevParseSingle(out objHandle, this.RepoHandle, commitish) != Native.ResultCode.Success)
             {
                 return null;
             }
@@ -99,7 +99,7 @@ public virtual bool CommitAndRootTreeExists(string commitish, out string treeSha
         public virtual bool ObjectExists(string sha)
         {
             IntPtr objHandle;
-            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.SuccessCode)
+            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.ResultCode.Success)
             {
                 return false;
             }
@@ -111,7 +111,7 @@ public virtual bool ObjectExists(string sha)
         public virtual bool TryCopyBlob(string sha, Action<Stream, long> writeAction)
         {
             IntPtr objHandle;
-            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.SuccessCode)
+            if (Native.RevParseSingle(out objHandle, this.RepoHandle, sha) != Native.ResultCode.Success)
             {
                 return false;
             }
@@ -157,7 +157,7 @@ public virtual string[] GetMissingSubTrees(string treeSha)
         {
             List<string> missingSubtreesList = new List<string>();
             IntPtr treeHandle;
-            if (Native.RevParseSingle(out treeHandle, this.RepoHandle, treeSha) != Native.SuccessCode
+            if (Native.RevParseSingle(out treeHandle, this.RepoHandle, treeSha) != Native.ResultCode.Success
                 || treeHandle == IntPtr.Zero)
             {
                 return Array.Empty<string>();
@@ -187,6 +187,68 @@ public virtual string[] GetMissingSubTrees(string treeSha)
             return missingSubtreesList.ToArray();
         }
 
+        /// <summary>
+        /// Get a config value from the repo's git config.
+        /// </summary>
+        /// <param name="name">Name of the config entry</param>
+        /// <returns>The config value, or null if not found.</returns>
+        public virtual string GetConfigString(string name)
+        {
+            IntPtr configHandle;
+            if (Native.Config.GetConfig(out configHandle, this.RepoHandle) != Native.ResultCode.Success)
+            {
+                throw new LibGit2Exception($"Failed to get config handle: {Native.GetLastError()}");
+            }
+            try
+            {
+                string value;
+                Native.ResultCode resultCode = Native.Config.GetString(out value, configHandle, name);
+                if (resultCode == Native.ResultCode.NotFound)
+                {
+                    return null;
+                }
+                else if (resultCode != Native.ResultCode.Success)
+                {
+                    throw new LibGit2Exception($"Failed to get config value for '{name}': {Native.GetLastError()}");
+                }
+
+                return value;
+            }
+            finally
+            {
+                Native.Config.Free(configHandle);
+            }
+        }
+
+        public virtual bool? GetConfigBool(string name)
+        {
+            IntPtr configHandle;
+            if (Native.Config.GetConfig(out configHandle, this.RepoHandle) != Native.ResultCode.Success)
+            {
+                throw new LibGit2Exception($"Failed to get config handle: {Native.GetLastError()}");
+            }
+            try
+            {
+                bool value;
+                Native.ResultCode resultCode = Native.Config.GetBool(out value, configHandle, name);
+                if (resultCode == Native.ResultCode.NotFound)
+                {
+                    return null;
+                }
+                else if (resultCode != Native.ResultCode.Success)
+                {
+                    throw new LibGit2Exception($"Failed to get config value for '{name}': {Native.GetLastError()}");
+                }
+
+                return value;
+            }
+            finally
+            {
+                Native.Config.Free(configHandle);
+            }
+
+        }
+
         /// <summary>
         /// Determine if the given index of a tree is a subtree and if it is missing.
         /// If it is a missing subtree, return the SHA of the subtree.
@@ -242,7 +304,11 @@ protected virtual void Dispose(bool disposing)
 
         public static class Native
         {
-            public const uint SuccessCode = 0;
+            public enum ResultCode : int
+            {
+                Success = 0,
+                NotFound = -3,
+            }
 
             public const string Git2NativeLibName = GVFSConstants.LibGit2LibraryName;
 
@@ -265,7 +331,7 @@ public static GitOid IntPtrToGitOid(IntPtr oidPtr)
             public static extern int Shutdown();
 
             [DllImport(Git2NativeLibName, EntryPoint = "git_revparse_single")]
-            public static extern uint RevParseSingle(out IntPtr objectHandle, IntPtr repoHandle, string oid);
+            public static extern ResultCode RevParseSingle(out IntPtr objectHandle, IntPtr repoHandle, string oid);
 
             public static string GetLastError()
             {
@@ -293,12 +359,27 @@ private struct GitError
             public static class Repo
             {
                 [DllImport(Git2NativeLibName, EntryPoint = "git_repository_open")]
-                public static extern uint Open(out IntPtr repoHandle, string path);
+                public static extern ResultCode Open(out IntPtr repoHandle, string path);
 
                 [DllImport(Git2NativeLibName, EntryPoint = "git_repository_free")]
                 public static extern void Free(IntPtr repoHandle);
             }
 
+            public static class Config
+            {
+                [DllImport(Git2NativeLibName, EntryPoint = "git_repository_config")]
+                public static extern ResultCode GetConfig(out IntPtr configHandle, IntPtr repoHandle);
+
+                [DllImport(Git2NativeLibName, EntryPoint = "git_config_get_string")]
+                public static extern ResultCode GetString(out string value, IntPtr configHandle, string name);
+
+                [DllImport(Git2NativeLibName, EntryPoint = "git_config_get_bool")]
+                public static extern ResultCode GetBool(out bool value, IntPtr configHandle, string name);
+
+                [DllImport(Git2NativeLibName, EntryPoint = "git_config_free")]
+                public static extern void Free(IntPtr configHandle);
+            }
+
             public static class Object
             {
                 [DllImport(Git2NativeLibName, EntryPoint = "git_object_type")]

GVFS/GVFS.Common/Git/LibGit2RepoInvoker.cs

@@ -13,6 +13,11 @@ public class LibGit2RepoInvoker : IDisposable
         private volatile int activeCallers;
         private LibGit2Repo sharedRepo;
 
+        public LibGit2RepoInvoker(ITracer tracer, string repoPath)
+            : this(tracer, () => new LibGit2Repo(tracer, repoPath))
+        {
+        }
+
         public LibGit2RepoInvoker(ITracer tracer, Func<LibGit2Repo> createRepo)
         {
             this.tracer = tracer;
@@ -82,6 +87,17 @@ public void InitializeSharedRepo()
             this.GetSharedRepo()?.ObjectExists("30380be3963a75e4a34e10726795d644659e1129");
         }
 
+        public bool GetConfigBoolOrDefault(string key, bool defaultValue)
+        {
+            bool? value = defaultValue;
+            if (this.TryInvoke(repo => repo.GetConfigBool(key), out value))
+            {
+                return value ?? defaultValue;
+            }
+
+            return defaultValue;
+        }
+
         private LibGit2Repo GetSharedRepo()
         {
             lock (this.sharedRepoLock)

GVFS/GVFS.Common/GitStatusCache.cs

@@ -341,7 +341,8 @@ private void RebuildStatusCacheIfNeeded(bool ignoreBackoff)
 
         private void UpdateHydrationSummary()
         {
-            bool enabled = TEST_EnableHydrationSummaryOverride ?? this.context.Enlistment.GetStatusHydrationConfig();
+            bool enabled = TEST_EnableHydrationSummaryOverride
+                ?? this.context.Repository.LibGit2RepoInvoker.GetConfigBoolOrDefault(GVFSConstants.GitConfig.ShowHydrationStatus, GVFSConstants.GitConfig.ShowHydrationStatusDefault);
             if (!enabled)
             {
                 return;

GVFS/GVFS.Common/Maintenance/PrefetchStep.cs

@@ -56,7 +56,9 @@ public bool TryPrefetchCommitsAndTrees(out string error, GitProcess gitProcess =
                     return false;
                 }
 
-                if (!this.GitObjects.TryDownloadPrefetchPacks(gitProcess, maxGoodTimeStamp, out packIndexes))
+                var trustPackIndexes = this.Context.Repository.LibGit2RepoInvoker.GetConfigBoolOrDefault(GVFSConstants.GitConfig.TrustPackIndexes, GVFSConstants.GitConfig.TrustPackIndexesDefault);
+
+                if (!this.GitObjects.TryDownloadPrefetchPacks(gitProcess, maxGoodTimeStamp, trustPackIndexes, out packIndexes))
                 {
                     error = "Failed to download prefetch packs";
                     return false;