Add Archive() to ObjectDatabase

LibGit2Sharp.Tests/ArchiveFixture.cs

@@ -0,0 +1,100 @@
+using System;
+using System.Collections;
+using System.IO;
+using LibGit2Sharp.Tests.TestHelpers;
+using Xunit;
+
+namespace LibGit2Sharp.Tests
+{
+    public class ArchiveFixture : BaseFixture
+    {
+        [Fact]
+        public void CanArchiveATree()
+        {
+            using (var repo = new Repository(BareTestRepoPath))
+            {
+                var tree = repo.Lookup<Tree>("581f9824ecaf824221bd36edf5430f2739a7c4f5");
+
+                var archiver = new MockArchiver();
+
+                repo.ObjectDatabase.Archive(tree, archiver);
+
+                var expected = new ArrayList
+                {
+                    new { Path = "1", Sha = "7f76480d939dc401415927ea7ef25c676b8ddb8f" },
+                    new { Path = Path.Combine("1", "branch_file.txt"), Sha = "45b983be36b73c0788dc9cbcb76cbb80fc7bb057" },
+                    new { Path = "README", Sha = "a8233120f6ad708f843d861ce2b7228ec4e3dec6" },
+                    new { Path = "branch_file.txt", Sha = "45b983be36b73c0788dc9cbcb76cbb80fc7bb057" },
+                    new { Path = "new.txt", Sha = "a71586c1dfe8a71c6cbf6c129f404c5642ff31bd" },
+                };
+                Assert.Equal(expected, archiver.Files);
+                Assert.Null(archiver.ReceivedCommitSha);
+                Assert.InRange(archiver.ModificationTime, DateTimeOffset.UtcNow.Subtract(TimeSpan.FromMilliseconds(100)), DateTimeOffset.UtcNow);
+            }
+        }
+
+        [Fact]
+        public void CanArchiveACommit()
+        {
+            using (var repo = new Repository(BareTestRepoPath))
+            {
+                var commit = repo.Lookup<Commit>("4c062a6361ae6959e06292c1fa5e2822d9c96345");
+
+                var archiver = new MockArchiver();
+
+                repo.ObjectDatabase.Archive(commit, archiver);
+
+                var expected = new ArrayList
+                {
+                    new { Path = "1", Sha = "7f76480d939dc401415927ea7ef25c676b8ddb8f" },
+                    new { Path = Path.Combine("1", "branch_file.txt"), Sha = "45b983be36b73c0788dc9cbcb76cbb80fc7bb057" },
+                    new { Path = "README", Sha = "a8233120f6ad708f843d861ce2b7228ec4e3dec6" },
+                    new { Path = "branch_file.txt", Sha = "45b983be36b73c0788dc9cbcb76cbb80fc7bb057" },
+                    new { Path = "new.txt", Sha = "a71586c1dfe8a71c6cbf6c129f404c5642ff31bd" },
+                };
+                Assert.Equal(expected, archiver.Files);
+                Assert.Equal(commit.Sha, archiver.ReceivedCommitSha);
+                Assert.Equal(commit.Committer.When, archiver.ModificationTime);
+            }
+        }
+
+        [Fact]
+        public void ArchivingANullTreeOrCommitThrows()
+        {
+            using (var repo = new Repository(BareTestRepoPath))
+            {
+                Assert.Throws<ArgumentNullException>(() => repo.ObjectDatabase.Archive((Commit)null, null));
+                Assert.Throws<ArgumentNullException>(() => repo.ObjectDatabase.Archive((Tree)null, null));
+            }
+        }
+
+        #region MockArchiver
+
+        private class MockArchiver : ArchiverBase
+        {
+            public readonly ArrayList Files = new ArrayList();
+            public string ReceivedCommitSha;
+            public DateTimeOffset ModificationTime;
+
+            #region Overrides of ArchiverBase
+
+            public override void BeforeArchiving(Tree tree, ObjectId oid, DateTimeOffset modificationTime)
+            {
+                if (oid != null)
+                {
+                    ReceivedCommitSha = oid.Sha;
+                }
+                ModificationTime = modificationTime;
+            }
+
+            protected override void AddTreeEntry(string path, TreeEntry entry, DateTimeOffset modificationTime)
+            {
+                Files.Add(new { Path = path, entry.Target.Sha });
+            }
+
+            #endregion
+        }
+
+        #endregion
+    }
+}

LibGit2Sharp.Tests/LibGit2Sharp.Tests.csproj

@@ -76,6 +76,7 @@
     <Compile Include="SubmoduleFixture.cs" />
     <Compile Include="IgnoreFixture.cs" />
     <Compile Include="FetchHeadFixture.cs" />
+    <Compile Include="ArchiveFixture.cs" />
     <Compile Include="MergeFixture.cs" />
     <Compile Include="CleanFixture.cs" />
     <Compile Include="CurrentOperationFixture.cs" />

LibGit2Sharp/ArchiverBase.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+namespace LibGit2Sharp
+{
+    /// <summary>
+    /// The archiving method needs to be passed an inheritor of this class, which will then be used
+    /// to provide low-level archiving facilities (tar, zip, ...).
+    /// <para>
+    ///   <see cref="ObjectDatabase.Archive(LibGit2Sharp.Commit,LibGit2Sharp.ArchiverBase)"/>
+    /// </para>
+    /// </summary>
+    public abstract class ArchiverBase
+    {
+        /// <summary>
+        /// Override this method to perform operations before the archiving of each entry of the tree takes place.
+        /// </summary>
+        /// <param name="tree">The tree that will be archived</param>
+        /// <param name="oid">The ObjectId of the commit being archived, or null if there is no commit.</param>
+        /// <param name="modificationTime">The modification time that will be used for the files in the archive.</param>
+        public virtual void BeforeArchiving(Tree tree, ObjectId oid, DateTimeOffset modificationTime)
+        { }
+
+        /// <summary>
+        /// Override this method to perform operations after the archiving of each entry of the tree took place.
+        /// </summary>
+        /// <param name="tree">The tree that was archived</param>
+        /// <param name="oid">The ObjectId of the commit being archived, or null if there is no commit.</param>
+        /// <param name="modificationTime">The modification time that was used for the files in the archive.</param>
+        public virtual void AfterArchiving(Tree tree, ObjectId oid, DateTimeOffset modificationTime)
+        { }
+
+        internal void OrchestrateArchiving(Tree tree, ObjectId oid, DateTimeOffset modificationTime)
+        {
+            BeforeArchiving(tree, oid, modificationTime);
+
+            ArchiveTree(tree, "", modificationTime);
+
+            AfterArchiving(tree, oid, modificationTime);
+        }
+
+        private void ArchiveTree(IEnumerable<TreeEntry> tree, string path, DateTimeOffset modificationTime)
+        {
+            foreach (var entry in tree)
+            {
+                AddTreeEntry(Path.Combine(path, entry.Name), entry, modificationTime);
+
+                // Recurse if we have subtrees
+                if (entry.Mode == Mode.Directory)
+                {
+                    ArchiveTree((Tree)entry.Target, Path.Combine(path, entry.Name), modificationTime);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Implements the archiving of a TreeEntry in a given format.
+        /// </summary>
+        /// <param name="path">The path of the entry in the archive.</param>
+        /// <param name="entry">The entry to archive.</param>
+        /// <param name="modificationTime">The datetime the entry was last modified.</param>
+        protected abstract void AddTreeEntry(string path, TreeEntry entry, DateTimeOffset modificationTime);
+    }
+}

LibGit2Sharp/LibGit2Sharp.csproj

@@ -56,6 +56,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AmbiguousSpecificationException.cs" />
+    <Compile Include="ArchiverBase.cs" />
     <Compile Include="BareRepositoryException.cs" />
     <Compile Include="BlameHunkCollection.cs" />
     <Compile Include="BlameHunk.cs" />

LibGit2Sharp/ObjectDatabase.cs

@@ -7,6 +7,7 @@
 using System.Runtime.InteropServices;
 using LibGit2Sharp.Core;
 using LibGit2Sharp.Core.Handles;
+using LibGit2Sharp.Handlers;
 
 namespace LibGit2Sharp
 {
@@ -236,6 +237,32 @@ public virtual TagAnnotation CreateTagAnnotation(string name, GitObject target,
             return repo.Lookup<TagAnnotation>(tagId);
         }
 
+        /// <summary>
+        /// Archive the given commit.
+        /// </summary>
+        /// <param name="commit">The commit.</param>
+        /// <param name="archiver">The archiver to use.</param>
+        public virtual void Archive(Commit commit, ArchiverBase archiver)
+        {
+            Ensure.ArgumentNotNull(commit, "commit");
+            Ensure.ArgumentNotNull(archiver, "archiver");
+
+            archiver.OrchestrateArchiving(commit.Tree, commit.Id, commit.Committer.When);
+        }
+
+        /// <summary>
+        /// Archive the given tree.
+        /// </summary>
+        /// <param name="tree">The tree.</param>
+        /// <param name="archiver">The archiver to use.</param>
+        public virtual void Archive(Tree tree, ArchiverBase archiver)
+        {
+            Ensure.ArgumentNotNull(tree, "tree");
+            Ensure.ArgumentNotNull(archiver, "archiver");
+
+            archiver.OrchestrateArchiving(tree, null, DateTimeOffset.UtcNow);
+        }
+
         /// <summary>
         /// Returns the merge base (best common ancestor) of the given commits
         /// and the distance between each of these commits and this base.