Extend IGitConfiguration to allow manipulating multivars

mjcheetham · mjcheetham · commit 040bb9e50cd0 · 2019-09-04T15:55:36.000+01:00
Extend the IGitConfiguration to allow manipulation of Git configuration
'multivars' (config entries that can have multiple values). This will be
used in future commits to set the credential.helper variable to have two
values.
diff --git a/src/shared/Microsoft.Git.CredentialManager/IGit.cs b/src/shared/Microsoft.Git.CredentialManager/IGit.cs
@@ -13,13 +13,57 @@ public interface IGitConfiguration : IDisposable
         /// <param name="cb">Callback to invoke for each configuration entry.</param>
         void Enumerate(GitConfigurationEnumerationCallback cb);
 
+        /// <summary>
+        /// Get a snapshot of the configuration filtered to the specified level.
+        /// </summary>
+        /// <param name="level">Configuration level filter.</param>
+        /// <returns>Git configuration snapshot.</returns>
+        IGitConfiguration GetFilteredConfiguration(GitConfigurationLevel level);
+
         /// <summary>
         /// Try and get the value of a configuration entry as a string.
         /// </summary>
         /// <param name="name">Configuration entry name.</param>
         /// <param name="value">Configuration entry value.</param>
         /// <returns>True if the value was found, false otherwise.</returns>
         bool TryGetValue(string name, out string value);
+
+        /// <summary>
+        /// Set the value of a configuration entry.
+        /// </summary>
+        /// <param name="name">Configuration entry name.</param>
+        /// <param name="value">Configuration entry value.</param>
+        void SetValue(string name, string value);
+
+        /// <summary>
+        /// Deletes a configuration entry from the highest level.
+        /// </summary>
+        /// <param name="name">Configuration entry name.</param>
+        void DeleteEntry(string name);
+
+        /// <summary>
+        /// Get all values of a multivar configuration entry.
+        /// </summary>
+        /// <param name="name">Configuration entry name.</param>
+        /// <param name="regexp">Regular expression to filter which variables we're interested in. Use null to indicate all.</param>
+        /// <returns>All values of the multivar configuration entry.</returns>
+        IEnumerable<string> GetMultivarValue(string name, string regexp);
+
+        /// <summary>
+        /// Set a multivar configuration entry value.
+        /// </summary>
+        /// <param name="name">Configuration entry name.</param>
+        /// <param name="regexp">Regular expression to indicate which values to replace.</param>
+        /// <param name="value">Configuration entry value.</param>
+        /// <remarks>If the regular expression does not match any existing entry, a new entry is created.</remarks>
+        void SetMultivarValue(string name, string regexp, string value);
+
+        /// <summary>
+        /// Deletes one or several entries from a multivar.
+        /// </summary>
+        /// <param name="name">Configuration entry name.</param>
+        /// <param name="regexp">Regular expression to indicate which values to delete.</param>
+        void DeleteMultivarEntry(string name, string regexp);
     }
 
     /// <summary>
@@ -47,6 +91,15 @@ public interface IGit : IDisposable
         string GetRepositoryPath(string path);
     }
 
+    public enum GitConfigurationLevel
+    {
+        ProgramData,
+        System,
+        Xdg,
+        Global,
+        Local,
+    }
+
     public static class GitExtensions
     {
         /// <summary>
diff --git a/src/shared/Microsoft.Git.CredentialManager/Interop/LibGit2.cs b/src/shared/Microsoft.Git.CredentialManager/Interop/LibGit2.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
 using System;
+using System.Collections.Generic;
 using System.IO;
 using Microsoft.Git.CredentialManager.Interop.Native;
 using static Microsoft.Git.CredentialManager.Interop.Native.git_config_level_t;
@@ -63,9 +64,8 @@ public string GetRepositoryPath(string path)
         {
             ThrowIfDisposed();
 
-            _trace.WriteLine($"Discovering repository from path '{path}'...");
-
             var buf = new git_buf();
+            _trace.WriteLine($"Discovering repository from path '{path}'...");
             int error = git_repository_discover(buf, path, true, null);
 
             try
@@ -91,6 +91,7 @@ public string GetRepositoryPath(string path)
 
         protected override void ReleaseUnmanagedResources()
         {
+            _trace.WriteLine("Shutting-down libgit2...");
             git_libgit2_shutdown();
             base.ReleaseUnmanagedResources();
         }
@@ -114,6 +115,8 @@ internal unsafe LibGit2Configuration(ITrace trace, git_config* config)
             _snapshot = snapshot;
         }
 
+        #region IGitConfiguration
+
         public unsafe void Enumerate(GitConfigurationEnumerationCallback cb)
         {
             ThrowIfDisposed();
@@ -143,6 +146,47 @@ int native_cb(git_config_entry entry, void* payload)
             }
         }
 
+        public unsafe IGitConfiguration GetFilteredConfiguration(GitConfigurationLevel level)
+        {
+            git_config* filteredConfig;
+
+            _trace.WriteLine($"Filtering default configuration set to '{level.ToString()}' level...");
+
+            // Filter to the requested level
+            switch (level)
+            {
+                case GitConfigurationLevel.ProgramData:
+                    ThrowIfError(git_config_open_level(&filteredConfig, _config, GIT_CONFIG_LEVEL_PROGRAMDATA),
+                        nameof(git_config_open_default));
+                    break;
+
+                case GitConfigurationLevel.System:
+                    ThrowIfError(git_config_open_level(&filteredConfig, _config, GIT_CONFIG_LEVEL_SYSTEM),
+                        nameof(git_config_open_default));
+                    break;
+
+                case GitConfigurationLevel.Xdg:
+                    ThrowIfError(git_config_open_level(&filteredConfig, _config, GIT_CONFIG_LEVEL_XDG),
+                        nameof(git_config_open_default));
+                    break;
+
+                case GitConfigurationLevel.Global:
+                    ThrowIfError(git_config_open_level(&filteredConfig, _config, GIT_CONFIG_LEVEL_GLOBAL),
+                        nameof(git_config_open_default));
+                    break;
+
+                case GitConfigurationLevel.Local:
+                    ThrowIfError(git_config_open_level(&filteredConfig, _config, GIT_CONFIG_LEVEL_LOCAL),
+                        nameof(git_config_open_default));
+                    break;
+
+                default:
+                    throw new ArgumentOutOfRangeException(nameof(level), level, null);
+            }
+
+            return new LibGit2Configuration(_trace, filteredConfig);
+        }
+
         public unsafe bool TryGetValue(string name, out string value)
         {
             ThrowIfDisposed();
@@ -167,6 +211,84 @@ public unsafe bool TryGetValue(string name, out string value)
             return false;
         }
 
+        public unsafe void SetValue(string name, string value)
+        {
+            _trace.WriteLine($"Setting Git configuration entry '{name}' to '{value}'...");
+            ThrowIfError(git_config_set_string(_config, name, value), nameof(git_config_set_string));
+        }
+
+        public unsafe void DeleteEntry(string name)
+        {
+            _trace.WriteLine($"Deleting Git configuration entry '{name}'...");
+
+            int result = git_config_delete_entry(_config, name);
+            switch (result)
+            {
+                case GIT_ENOTFOUND:
+                    // Do nothing if asked to delete non-existent key
+                    break;
+
+                default:
+                    ThrowIfError(result, nameof(git_config_delete_entry));
+                    break;
+            }
+        }
+
+        public unsafe IEnumerable<string> GetMultivarValue(string name, string regexp)
+        {
+            _trace.WriteLine($"Reading Git configuration multivar '{name}' (regexp: '{regexp}')...");
+
+            var values = new List<string>();
+
+            int value_callback(git_config_entry entry, void* payload)
+            {
+                string value = entry.GetValue();
+                _trace.WriteLine($"Found multivar value '{value}'.");
+                values.Add(value);
+                return 0;
+            }
+
+            int result = git_config_get_multivar_foreach(_config, name, regexp, value_callback, (void*) IntPtr.Zero);
+            switch (result)
+            {
+                case GIT_ENOTFOUND:
+                    // Do nothing if asked to enumerate non-existent multivar key
+                    _trace.WriteLine("No entry found.");
+                    break;
+
+                default:
+                    ThrowIfError(result, nameof(git_config_get_multivar_foreach));
+                    break;
+            }
+
+            return values;
+        }
+
+        public unsafe void SetMultivarValue(string name, string regexp, string value)
+        {
+            _trace.WriteLine($"Setting Git configuration multivar '{name}' (regexp: '{regexp}') to '{value}'...");
+            ThrowIfError(git_config_set_multivar(_config, name, regexp, value), nameof(git_config_set_multivar));
+        }
+
+        public unsafe void DeleteMultivarEntry(string name, string regexp)
+        {
+            _trace.WriteLine($"Deleting Git configuration multivar '{name}' (regexp: '{regexp}')...");
+
+            int result = git_config_delete_multivar(_config, name, regexp);
+            switch (result)
+            {
+                case GIT_ENOTFOUND:
+                    // Do nothing if asked to delete non-existent key
+                    break;
+
+                default:
+                    ThrowIfError(result, nameof(git_config_delete_multivar));
+                    break;
+            }
+        }
+
+        #endregion
+
         protected override void ReleaseUnmanagedResources()
         {
             unsafe
diff --git a/src/shared/Microsoft.Git.CredentialManager/Interop/Native/LibGit2.Error.cs b/src/shared/Microsoft.Git.CredentialManager/Interop/Native/LibGit2.Error.cs
@@ -164,15 +164,20 @@ public static void ThrowIfError(int result, string functionName = null)
             {
                 unsafe
                 {
-                    git_error error = git_error_last();
-
-                    string errorMessage = U8StringConverter.ToManaged(error.message);
-
                     string mainMessage = functionName is null
                         ? $"libgit2 '{functionName}' returned non-zero value"
                         : "libgit2 returned non-zero value";
 
-                    throw new InteropException(mainMessage, result, new Exception(errorMessage));
+                    git_error* error = git_error_last();
+
+                    if (error != null && error->message != null)
+                    {
+                        string errorMessage = U8StringConverter.ToManaged(error->message);
+
+                        throw new InteropException(mainMessage, result, new Exception(errorMessage));
+                    }
+
+                    throw new InteropException(mainMessage, result);
                 }
             }
         }
diff --git a/src/shared/Microsoft.Git.CredentialManager/Interop/Native/LibGit2.cs b/src/shared/Microsoft.Git.CredentialManager/Interop/Native/LibGit2.cs
@@ -38,7 +38,7 @@ public static partial class LibGit2
         public static extern int git_libgit2_shutdown();
 
         [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
-        public static extern git_error git_error_last();
+        public static extern unsafe git_error* git_error_last();
 
         [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
         public static extern void git_buf_dispose(git_buf buf);
@@ -75,9 +75,55 @@ public static extern unsafe int git_config_get_string(
         [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
         public static extern unsafe int git_config_foreach(git_config* cfg, git_config_foreach_cb callback, void* payload);
 
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern unsafe int git_config_set_string(
+            git_config* cfg,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string name,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string value);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern unsafe int git_config_delete_entry(
+            git_config* cfg,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string name);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern unsafe int git_config_get_multivar_foreach(
+            git_config* cfg,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string name,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string regexp,
+            git_config_foreach_cb callback,
+            void *payload);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern unsafe int git_config_set_multivar(
+            git_config* cfg,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string name,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string regexp,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string value);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern unsafe int git_config_delete_multivar(
+            git_config* cfg,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string name,
+            [MarshalAs(CustomMarshaler, MarshalCookie = NativeCookie, MarshalTypeRef = typeof(U8StringMarshaler))]
+            string regexp);
+
+
         [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
         public static extern unsafe int git_config_open_default(git_config** @out);
 
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern unsafe int git_config_open_level(git_config** @out, git_config* parent, git_config_level_t level);
+
         [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
         public static extern unsafe int git_config_snapshot(git_config** @out, git_config* config);
     }
@@ -86,9 +132,9 @@ public static extern unsafe int git_config_get_string(
     public delegate void git_config_entry_free_callback(git_config_entry entry);
 
     [StructLayout(LayoutKind.Sequential)]
-    public class git_error
+    public unsafe struct git_error
     {
-        public unsafe byte* message;
+        public byte* message;
         public int klass;
     }
 
diff --git a/src/shared/TestInfrastructure/Objects/TestGit.cs b/src/shared/TestInfrastructure/Objects/TestGit.cs
diff --git a/src/shared/TestInfrastructure/Objects/TestGitConfiguration.cs b/src/shared/TestInfrastructure/Objects/TestGitConfiguration.cs

Original file line number	Diff line number	Diff line change
`@@ -164,15 +164,20 @@ public static void ThrowIfError(int result, string functionName = null)`
`164`	`164`	`{`
`165`	`165`	`unsafe`
`166`	`166`	`{`
`167`		`- git_error error = git_error_last();`
`168`		`-`
`169`		`- string errorMessage = U8StringConverter.ToManaged(error.message);`
`170`		`-`
`171`	`167`	`string mainMessage = functionName is null`
`172`	`168`	`? $"libgit2 '{functionName}' returned non-zero value"`
`173`	`169`	`: "libgit2 returned non-zero value";`
`174`	`170`
`175`		`- throw new InteropException(mainMessage, result, new Exception(errorMessage));`
	`171`	`+ git_error* error = git_error_last();`
	`172`	`+`
	`173`	`+ if (error != null && error->message != null)`
	`174`	`+ {`
	`175`	`+ string errorMessage = U8StringConverter.ToManaged(error->message);`
	`176`	`+`
	`177`	`+ throw new InteropException(mainMessage, result, new Exception(errorMessage));`
	`178`	`+ }`
	`179`	`+`
	`180`	`+ throw new InteropException(mainMessage, result);`
`176`	`181`	`}`
`177`	`182`	`}`
`178`	`183`	`}`