Make ObjectDatabase.CreateBlob() able to accept a BinaryReader

Author: nulltoken

LibGit2Sharp.Tests/ObjectDatabaseFixture.cs

@@ -1,4 +1,5 @@
 using System.IO;
+using System.Text;
 using LibGit2Sharp.Tests.TestHelpers;
 using Xunit;
 using Xunit.Extensions;
@@ -76,6 +77,42 @@ public void CanCreateABlobIntoTheDatabaseOfABareRepository()
             }
         }
 
+        [Theory]
+        [InlineData("321cbdf08803c744082332332838df6bd160f8f9", null)]
+        [InlineData("321cbdf08803c744082332332838df6bd160f8f9", "dummy.data")]
+        [InlineData("e9671e138a780833cb689753570fd10a55be84fb", "dummy.txt")]
+        [InlineData("e9671e138a780833cb689753570fd10a55be84fb", "dummy.guess")]
+        public void CanCreateABlobFromABinaryReader(string expectedSha, string hintPath)
+        {
+            TemporaryCloneOfTestRepo scd = BuildTemporaryCloneOfTestRepo();
+
+            var sb = new StringBuilder();
+            for (int i = 0; i < 6; i++)
+            {
+                sb.Append("libgit2\n\r\n");
+            }
+
+            using (var repo = new Repository(scd.RepositoryPath))
+            {
+                CreateAttributesFiles(Path.Combine(repo.Info.Path, "info"), "attributes");
+
+                using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(sb.ToString())))
+                using (var binReader = new BinaryReader(stream))
+                {
+                    Blob blob = repo.ObjectDatabase.CreateBlob(binReader, hintPath);
+                    Assert.Equal(expectedSha, blob.Sha);
+                }
+            }
+        }
+
+        private static void CreateAttributesFiles(string where, string filename)
+        {
+            const string attributes = "* text=auto\n*.txt text\n*.data binary\n";
+
+            Directory.CreateDirectory(where);
+            File.WriteAllText(Path.Combine(where, filename), attributes);
+        }
+
         [Theory]
         [InlineData("README")]
         [InlineData("README AS WELL")]

LibGit2Sharp/Core/NativeMethods.cs

@@ -79,6 +79,19 @@ public static extern int git_blob_create_fromfile(
             RepositorySafeHandle repo,
             [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(FilePathMarshaler))] FilePath path);
 
+        internal delegate int source_callback(
+            IntPtr content,
+            int max_length,
+            IntPtr data);
+
+        [DllImport(libgit2)]
+        public static extern int git_blob_create_fromchunks(
+            ref GitOid oid,
+            RepositorySafeHandle repositoryPtr,
+            [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(FilePathMarshaler))] FilePath hintpath,
+            source_callback fileCallback,
+            IntPtr data);
+        
         [DllImport(libgit2)]
         public static extern IntPtr git_blob_rawcontent(GitObjectSafeHandle blob);
 

LibGit2Sharp/ObjectDatabase.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.InteropServices;
 using LibGit2Sharp.Core;
 using LibGit2Sharp.Core.Handles;
 
@@ -67,6 +68,44 @@ public virtual Blob CreateBlob(string path)
             return repo.Lookup<Blob>(new ObjectId(oid));
         }
 
+        private class Processor
+        {
+            private readonly BinaryReader _reader;
+
+            public Processor(BinaryReader reader)
+            {
+                _reader = reader;
+            }
+
+            public int Provider(IntPtr content, int max_length, IntPtr data)
+            {
+                var local = new byte[max_length];
+                int numberOfReadBytes = _reader.Read(local, 0, max_length);
+
+                Marshal.Copy(local, 0, content, numberOfReadBytes);
+
+                return numberOfReadBytes;
+            }
+        }
+
+        /// <summary>
+        ///   Inserts a <see cref="Blob"/> into the object database, created from the content of a data provider.
+        /// </summary>
+        /// <param name="reader">The reader that will provide the content of the blob to be created.</param>
+        /// <param name="hintpath">The hintpath is used to determine what git filters should be applied to the object before it can be placed to the object database.</param>
+        /// <returns>The created <see cref="Blob"/>.</returns>
+        public virtual Blob CreateBlob(BinaryReader reader, string hintpath = null)
+        {
+            Ensure.ArgumentNotNull(reader, "reader");
+
+            var oid = new GitOid();
+
+            var proc = new Processor(reader);
+            Ensure.Success(NativeMethods.git_blob_create_fromchunks(ref oid, repo.Handle, hintpath, proc.Provider, IntPtr.Zero));
+
+            return repo.Lookup<Blob>(new ObjectId(oid));
+        }
+
         /// <summary>
         ///   Inserts a <see cref = "Tree"/> into the object database, created from a <see cref = "TreeDefinition"/>.
         /// </summary>