Teach Network to list references on a remote

LibGit2Sharp.Tests/LibGit2Sharp.Tests.csproj

@@ -69,6 +69,7 @@
     <Compile Include="ConfigurationFixture.cs" />
     <Compile Include="AttributesFixture.cs" />
     <Compile Include="CommitAncestorFixture.cs" />
+    <Compile Include="NetworkFixture.cs" />
     <Compile Include="NoteFixture.cs" />
     <Compile Include="DiffBlobToBlobFixture.cs" />
     <Compile Include="DiffTreeToTargetFixture.cs" />

LibGit2Sharp.Tests/NetworkFixture.cs

@@ -0,0 +1,96 @@
+using System.Collections.Generic;
+using System.Linq;
+using LibGit2Sharp.Core.Compat;
+using LibGit2Sharp.Tests.TestHelpers;
+using Xunit;
+using Xunit.Extensions;
+
+namespace LibGit2Sharp.Tests
+{
+    public class NetworkFixture : BaseFixture
+    {
+        [Theory]
+        [InlineData("https://github.com/libgit2/TestGitRepository")]
+        [InlineData("https://github.com/libgit2/TestGitRepository")]
+        [InlineData("git://github.com/libgit2/TestGitRepository.git")]
+        public void CanListRemoteReferences(string url)
+        {
+            string remoteName = "testRemote";
+
+            var scd = BuildSelfCleaningDirectory();
+            using (var repo = Repository.Init(scd.RootedDirectoryPath))
+            {
+                Remote remote = repo.Network.Remotes.Add(remoteName, url);
+                IEnumerable<DirectReference> references = repo.Network.ListReferences(remote);
+
+                List<Tuple<string, string>> actualRefs = references.
+                    Select(directRef => new Tuple<string, string>(directRef.CanonicalName, directRef.TargetIdentifier)).ToList();
+
+                Assert.Equal(ExpectedRemoteRefs.Count, actualRefs.Count);
+                for (int i = 0; i < ExpectedRemoteRefs.Count; i++)
+                {
+                    Assert.Equal(ExpectedRemoteRefs[i].Item2, actualRefs[i].Item2);
+                    Assert.Equal(ExpectedRemoteRefs[i].Item1, actualRefs[i].Item1);
+                }
+            }
+        }
+
+        [Fact]
+        public void CanListRemoteReferenceObjects()
+        {
+            string url = "https://github.com/libgit2/TestGitRepository";
+            string remoteName = "origin";
+
+            var scd = BuildSelfCleaningDirectory();
+            using (Repository repo = Repository.Clone(url, scd.RootedDirectoryPath))
+            {
+                Remote remote = repo.Network.Remotes[remoteName];
+                IEnumerable<DirectReference> references = repo.Network.ListReferences(remote);
+
+                List<Tuple<string, string>> actualRefs = new List<Tuple<string,string>>();
+
+                foreach(DirectReference reference in references)
+                {
+                    Assert.NotNull(reference.CanonicalName);
+                    Assert.NotNull(reference.Target);
+                    actualRefs.Add(new Tuple<string, string>(reference.CanonicalName, reference.Target.Id.Sha));
+                }
+
+                Assert.Equal(ExpectedRemoteRefs.Count, actualRefs.Count);
+                for (int i = 0; i < ExpectedRemoteRefs.Count; i++)
+                {
+                    Assert.Equal(ExpectedRemoteRefs[i].Item1, actualRefs[i].Item1);
+                    Assert.Equal(ExpectedRemoteRefs[i].Item2, actualRefs[i].Item2);
+                }
+            }
+        }
+
+        /*
+        * git ls-remote https://github.com/libgit2/TestGitRepository
+        * 49322bb17d3acc9146f98c97d078513228bbf3c0        HEAD
+        * 0966a434eb1a025db6b71485ab63a3bfbea520b6        refs/heads/first-merge
+        * 49322bb17d3acc9146f98c97d078513228bbf3c0        refs/heads/master
+        * 42e4e7c5e507e113ebbb7801b16b52cf867b7ce1        refs/heads/no-parent
+        * d96c4e80345534eccee5ac7b07fc7603b56124cb        refs/tags/annotated_tag
+        * c070ad8c08840c8116da865b2d65593a6bb9cd2a        refs/tags/annotated_tag^{}
+        * 55a1a760df4b86a02094a904dfa511deb5655905        refs/tags/blob
+        * 8f50ba15d49353813cc6e20298002c0d17b0a9ee        refs/tags/commit_tree
+        * 6e0c7bdb9b4ed93212491ee778ca1c65047cab4e        refs/tags/nearly-dangling
+        */
+        /// <summary>
+        /// Expected references on https://github.com/libgit2/TestGitRepository
+        /// </summary>
+        private static List<Tuple<string, string>> ExpectedRemoteRefs = new List<Tuple<string, string>>()
+        {
+            new Tuple<string, string>("HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0"),
+            new Tuple<string, string>("refs/heads/first-merge", "0966a434eb1a025db6b71485ab63a3bfbea520b6"),
+            new Tuple<string, string>("refs/heads/master", "49322bb17d3acc9146f98c97d078513228bbf3c0"),
+            new Tuple<string, string>("refs/heads/no-parent", "42e4e7c5e507e113ebbb7801b16b52cf867b7ce1"),
+            new Tuple<string, string>("refs/tags/annotated_tag", "d96c4e80345534eccee5ac7b07fc7603b56124cb"),
+            new Tuple<string, string>("refs/tags/annotated_tag^{}", "c070ad8c08840c8116da865b2d65593a6bb9cd2a"),
+            new Tuple<string, string>("refs/tags/blob", "55a1a760df4b86a02094a904dfa511deb5655905"),
+            new Tuple<string, string>("refs/tags/commit_tree", "8f50ba15d49353813cc6e20298002c0d17b0a9ee"),
+            new Tuple<string, string>("refs/tags/nearly-dangling", "6e0c7bdb9b4ed93212491ee778ca1c65047cab4e"),
+        };
+    }
+}

LibGit2Sharp/Core/GitRemoteHead.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace LibGit2Sharp.Core
+{
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct GitRemoteHead
+    {
+        public bool Local;
+        public GitOid Oid;
+        public GitOid Loid;
+        public IntPtr NamePtr;
+    }
+}

LibGit2Sharp/Core/NativeMethods.cs

@@ -690,6 +690,11 @@ internal static extern void git_remote_set_cred_acquire_cb(
         [DllImport(libgit2)]
         internal static extern void git_remote_disconnect(RemoteSafeHandle remote);
 
+        [DllImport(libgit2)]
+        internal static extern int git_remote_ls(RemoteSafeHandle remote, git_headlist_cb headlist_cb, IntPtr payload);
+
+        internal delegate int git_headlist_cb(ref GitRemoteHead remoteHeadPtr, IntPtr payload);
+
         [DllImport(libgit2)]
         internal static extern int git_remote_download(
             RemoteSafeHandle remote,

LibGit2Sharp/Core/Proxy.cs

@@ -1270,6 +1270,15 @@ public static IList<string> git_remote_list(RepositorySafeHandle repo)
             }
         }
 
+        public static void git_remote_ls(RemoteSafeHandle remote, NativeMethods.git_headlist_cb headlist_cb)
+        {
+            using (ThreadAffinity())
+            {
+                int res = NativeMethods.git_remote_ls(remote, headlist_cb, IntPtr.Zero);
+                Ensure.ZeroResult(res);
+            }
+        }
+
         public static RemoteSafeHandle git_remote_load(RepositorySafeHandle repo, string name, bool throwsIfNotFound)
         {
             using (ThreadAffinity())

LibGit2Sharp/LibGit2Sharp.csproj

@@ -66,6 +66,7 @@
     <Compile Include="CheckoutCallbacks.cs" />
     <Compile Include="CheckoutOptions.cs" />
     <Compile Include="Network.cs" />
+    <Compile Include="Core\GitRemoteHead.cs" />
     <Compile Include="OrphanedHeadException.cs" />
     <Compile Include="UnmergedIndexEntriesException.cs" />
     <Compile Include="Commit.cs" />

LibGit2Sharp/Network.cs

@@ -52,6 +52,43 @@ public virtual RemoteCollection Remotes
             get { return remotes.Value; }
         }
 
+        /// <summary>
+        ///   List references in a <see cref = "Remote" /> repository.
+        /// </summary>
+        /// <param name="remote">The <see cref = "Remote" /> to list from.</param>
+        /// <returns>The references in the <see cref = "Remote" /> repository.</returns>
+        public virtual IEnumerable<DirectReference> ListReferences(Remote remote)
+        {
+            Ensure.ArgumentNotNull(remote, "remote");
+
+            List<DirectReference> directReferences = new List<DirectReference>();
+            using (RemoteSafeHandle remoteHandle = Proxy.git_remote_load(repository.Handle, remote.Name, true))
+            {
+                Proxy.git_remote_connect(remoteHandle, GitDirection.Fetch);
+
+                NativeMethods.git_headlist_cb cb = (ref GitRemoteHead remoteHead, IntPtr payload) =>
+                {
+                    // The name pointer should never be null - if it is,
+                    // this indicates a bug somewhere (libgit2, server, etc).
+                    if (remoteHead.NamePtr == IntPtr.Zero)
+                    {
+                        Proxy.giterr_set_str(GitErrorCategory.Invalid, "Not expecting null value for reference name.");
+                        return -1;
+                    }
+
+                    ObjectId oid = new ObjectId(remoteHead.Oid);
+                    string name = Utf8Marshaler.FromNative(remoteHead.NamePtr);
+                    directReferences.Add(new DirectReference(name, this.repository, oid));
+
+                    return 0;
+                };
+
+                Proxy.git_remote_ls(remoteHandle, cb);
+            }
+
+            return directReferences;
+        }
+
         /// <summary>
         ///   Push the objectish to the destination reference on the <see cref = "Remote" />.
         /// </summary>