Merge pull request #122: Use GVFS Helper transport instead of read object hook

See microsoft/git#191 for the Git code regarding the GVFS transport layer. This can work in tandem with the read-object hook, but it _should_ make the read-object hook irrelevant.

* Delete all references to the read-object hook in the product code. This unblocks #4 and the [Mount Removal] tasks #15,  #132, #133, #135, #136, and possible others.

* Delete the Sparse Verb in favor of `git sparse-checkout set`.

* Delete the `BlobPrefetcher` and all references to `--files` or `--folders` prefetching.

Resolves #6, #7, #36.

Author: derrickstolee

Readme.md

@@ -152,12 +152,6 @@ Note that Scalar on Mac is under active development.
   git clone https://github.com/microsoft/scalar.git src
   ```
 
-* Using XCode, open `Scalar/ReadObjectHook/Scalar.ReadObjectHook.Mac.xcodeproj`.
-
-  * Select the `Scalar.ReadObjectHook.Mac` project.
-  * Under "Signing", select your developer certificate, which may be an organization
-    certificate.
-
 * Run the build and installation scripts:
 
   ```

Scalar.Build/Scalar.props

@@ -3,7 +3,7 @@
 
   <PropertyGroup Label="Parameters">
     <ScalarVersion>0.2.173.2</ScalarVersion>
-    <GitPackageVersion>2.20191002.1-sc</GitPackageVersion>
+    <GitPackageVersion>2.20191003.3-sc</GitPackageVersion>
   </PropertyGroup>
 
   <PropertyGroup Label="DefaultSettings">

Scalar.Common/FileSystem/HooksInstaller.cs

@@ -4,7 +4,6 @@ namespace Scalar.Common.Git
 {
     public class GitConfigSetting
     {
-        public const string CoreVirtualizeObjectsName = "core.virtualizeobjects";
         public const string CredentialUseHttpPath = "credential.\"https://dev.azure.com\".useHttpPath";
 
         public const string HttpSslCert = "http.sslcert";

Scalar.Common/Git/GitConfigSetting.cs

@@ -90,7 +90,7 @@ public static Result Init(Enlistment enlistment)
 
         public static Result SparseCheckoutInit(Enlistment enlistment)
         {
-            return new GitProcess(enlistment).InvokeGitInWorkingDirectoryRoot("sparse-checkout init --cone", useReadObjectHook: false);
+            return new GitProcess(enlistment).InvokeGitInWorkingDirectoryRoot("sparse-checkout init --cone", fetchMissingObjects: false);
         }
 
         public static ConfigResult GetFromGlobalConfig(string gitBinPath, string settingName)
@@ -413,19 +413,19 @@ public Result CreateBranchWithUpstream(string branchToCreate, string upstreamBra
 
         public Result ForceCheckout(string target)
         {
-            return this.InvokeGitInWorkingDirectoryRoot("checkout -f " + target, useReadObjectHook: true);
+            return this.InvokeGitInWorkingDirectoryRoot("checkout -f " + target, fetchMissingObjects: true);
         }
 
         public Result ForceCheckoutAllFiles()
         {
-            return this.InvokeGitInWorkingDirectoryRoot("checkout HEAD -- .", useReadObjectHook: true);
+            return this.InvokeGitInWorkingDirectoryRoot("checkout HEAD -- .", fetchMissingObjects: true);
         }
 
         public Result SparseCheckoutSet(List<string> foldersToSet)
         {
             return this.InvokeGitInWorkingDirectoryRoot(
                 $"sparse-checkout set --stdin",
-                useReadObjectHook: true,
+                fetchMissingObjects: true,
                 writeStdIn: writer =>
                 {
                     foreach (string path in foldersToSet)
@@ -449,7 +449,7 @@ public Result Status(bool allowObjectDownloads, bool useStatusCache, bool showUn
                 command += " -uall";
             }
 
-            return this.InvokeGitInWorkingDirectoryRoot(command, useReadObjectHook: allowObjectDownloads);
+            return this.InvokeGitInWorkingDirectoryRoot(command, fetchMissingObjects: allowObjectDownloads);
         }
 
         public Result UnpackObjects(Stream packFileStream)
@@ -490,7 +490,7 @@ public Result WriteCommitGraph(string objectDir, List<string> packs)
             string command = "commit-graph write --stdin-packs --split --size-multiple=4 --object-dir \"" + objectDir + "\"";
             return this.InvokeGitInWorkingDirectoryRoot(
                 command,
-                useReadObjectHook: true,
+                fetchMissingObjects: true,
                 writeStdIn: writer =>
                 {
                     foreach (string packIndex in packs)
@@ -506,7 +506,7 @@ public Result WriteCommitGraph(string objectDir, List<string> packs)
         public Result VerifyCommitGraph(string objectDir)
         {
             string command = "commit-graph verify --shallow --object-dir \"" + objectDir + "\"";
-            return this.InvokeGitInWorkingDirectoryRoot(command, useReadObjectHook: true);
+            return this.InvokeGitInWorkingDirectoryRoot(command, fetchMissingObjects: true);
         }
 
         public Result IndexPack(string packfilePath, string idxOutputPath)
@@ -547,7 +547,7 @@ public Result LsFiles(Action<string> parseStdOutLine)
         {
             return this.InvokeGitInWorkingDirectoryRoot(
                 "ls-files -v",
-                useReadObjectHook: false,
+                fetchMissingObjects: false,
                 parseStdOutLine: parseStdOutLine);
         }
 
@@ -588,7 +588,7 @@ public Result MultiPackIndexRepack(string gitObjectDirectory, string batchSize)
             return this.InvokeGitAgainstDotGitFolder($"-c pack.threads=1 multi-pack-index repack --object-dir=\"{gitObjectDirectory}\" --batch-size={batchSize}");
         }
 
-        public Process GetGitProcess(string command, string workingDirectory, string dotGitDirectory, bool useReadObjectHook, bool redirectStandardError, string gitObjectsDirectory)
+        public Process GetGitProcess(string command, string workingDirectory, string dotGitDirectory, bool fetchMissingObjects, bool redirectStandardError, string gitObjectsDirectory)
         {
             ProcessStartInfo processInfo = new ProcessStartInfo(this.gitBinPath);
             processInfo.WorkingDirectory = workingDirectory;
@@ -632,9 +632,9 @@ public Process GetGitProcess(string command, string workingDirectory, string dot
                 processInfo.EnvironmentVariables["GIT_OBJECT_DIRECTORY"] = gitObjectsDirectory;
             }
 
-            if (!useReadObjectHook)
+            if (!fetchMissingObjects)
             {
-                command = "-c " + GitConfigSetting.CoreVirtualizeObjectsName + "=false " + command;
+                command = $"-c {ScalarConstants.GitConfig.UseGvfsHelper}=false {command}";
             }
 
             if (!string.IsNullOrEmpty(dotGitDirectory))
@@ -654,7 +654,7 @@ protected virtual Result InvokeGitImpl(
             string command,
             string workingDirectory,
             string dotGitDirectory,
-            bool useReadObjectHook,
+            bool fetchMissingObjects,
             Action<StreamWriter> writeStdIn,
             Action<string> parseStdOutLine,
             int timeoutMs,
@@ -670,7 +670,13 @@ protected virtual Result InvokeGitImpl(
                 // From https://msdn.microsoft.com/en-us/library/system.diagnostics.process.standardoutput.aspx
                 // To avoid deadlocks, use asynchronous read operations on at least one of the streams.
                 // Do not perform a synchronous read to the end of both redirected streams.
-                using (this.executingProcess = this.GetGitProcess(command, workingDirectory, dotGitDirectory, useReadObjectHook, redirectStandardError: true, gitObjectsDirectory: gitObjectsDirectory))
+                using (this.executingProcess = this.GetGitProcess(
+                                                        command,
+                                                        workingDirectory,
+                                                        dotGitDirectory,
+                                                        fetchMissingObjects: fetchMissingObjects,
+                                                        redirectStandardError: true,
+                                                        gitObjectsDirectory: gitObjectsDirectory))
                 {
                     StringBuilder output = new StringBuilder();
                     StringBuilder errors = new StringBuilder();
@@ -793,7 +799,7 @@ private Result InvokeGitOutsideEnlistment(
                 command,
                 workingDirectory: Environment.SystemDirectory,
                 dotGitDirectory: null,
-                useReadObjectHook: false,
+                fetchMissingObjects: false,
                 writeStdIn: writeStdIn,
                 parseStdOutLine: parseStdOutLine,
                 timeoutMs: timeout);
@@ -804,15 +810,15 @@ private Result InvokeGitOutsideEnlistment(
         /// </summary>
         private Result InvokeGitInWorkingDirectoryRoot(
             string command,
-            bool useReadObjectHook,
+            bool fetchMissingObjects,
             Action<StreamWriter> writeStdIn = null,
             Action<string> parseStdOutLine = null)
         {
             return this.InvokeGitImpl(
                 command,
                 workingDirectory: this.workingDirectoryRoot,
                 dotGitDirectory: null,
-                useReadObjectHook: useReadObjectHook,
+                fetchMissingObjects: fetchMissingObjects,
                 writeStdIn: writeStdIn,
                 parseStdOutLine: parseStdOutLine,
                 timeoutMs: -1);
@@ -840,7 +846,7 @@ private Result InvokeGitAgainstDotGitFolder(
                 command,
                 workingDirectory: Environment.SystemDirectory,
                 dotGitDirectory: this.dotGitRoot,
-                useReadObjectHook: false,
+                fetchMissingObjects: false,
                 writeStdIn: writeStdIn,
                 parseStdOutLine: parseStdOutLine,
                 timeoutMs: -1,