transport: add object-info capability

Sometimes it is useful to obtain metadata associated with an object
without the need to first download it locally. This is specially useful
when using partial clones.

This change implements the object-info capability that allows clients to
query the remote server for object metadata (currently only size). This
is a backport of the same capability that was recently added to the Git
project a2ba162cda (object-info: support for retrieving object info,
2021-04-20).

Signed-off-by: Bruno Albuquerque <bga@google.com>
Change-Id: I4dc9828e1c247f08b0976b8810be92d124366165

1 files changed, 47 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
index b0b5f68efa..f4bbb4c9f8 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
@@ -460,6 +460,8 @@ public class UploadPackTest {
 
 		private FetchV2Request fetchRequest;
 
+		private ObjectInfoRequest objectInfoRequest;
+
 		@Override
 		public void onCapabilities(CapabilitiesV2Request req) {
 			capabilitiesRequest = req;
@@ -474,6 +476,11 @@ public class UploadPackTest {
 		public void onFetch(FetchV2Request req) {
 			fetchRequest = req;
 		}
+
+		@Override
+		public void onObjectInfo(ObjectInfoRequest req) {
+			objectInfoRequest = req;
+		}
 	}
 
 	@Test
@@ -2641,4 +2648,44 @@ public class UploadPackTest {
 			return refdb;
 		}
 	}
+
+	@Test
+	public void testObjectInfo() throws Exception {
+		server.getConfig().setBoolean("uploadpack", null, "advertiseobjectinfo",
+				true);
+
+		RevBlob blob1 = remote.blob("foobar");
+		RevBlob blob2 = remote.blob("fooba");
+		RevTree tree = remote.tree(remote.file("1", blob1),
+				remote.file("2", blob2));
+		RevCommit commit = remote.commit(tree);
+		remote.update("master", commit);
+
+		TestV2Hook hook = new TestV2Hook();
+		ByteArrayInputStream recvStream = uploadPackV2((UploadPack up) -> {
+			up.setProtocolV2Hook(hook);
+		}, "command=object-info\n", "size",
+				"oid " + ObjectId.toString(blob1.getId()),
+				"oid " + ObjectId.toString(blob2.getId()), PacketLineIn.end());
+		PacketLineIn pckIn = new PacketLineIn(recvStream);
+
+		assertThat(hook.objectInfoRequest, notNullValue());
+		assertThat(pckIn.readString(), is("size"));
+		assertThat(pckIn.readString(),
+				is(ObjectId.toString(blob1.getId()) + " 6"));
+		assertThat(pckIn.readString(),
+				is(ObjectId.toString(blob2.getId()) + " 5"));
+		assertTrue(PacketLineIn.isEnd(pckIn.readString()));
+	}
+
+	@Test
+	public void testObjectInfo_invalidOid() throws Exception {
+		server.getConfig().setBoolean("uploadpack", null, "advertiseobjectinfo",
+				true);
+
+		assertThrows(UploadPackInternalServerErrorException.class,
+				() -> uploadPackV2("command=object-info\n", "size",
+						"oid invalid",
+						PacketLineIn.end()));
+	}
 }