Teach UploadPack to support filtering by blob size

Teach UploadPack to advertise the filter capability and support a
"filter" line in the request, accepting blob sizes only, if the
configuration variable "uploadpack.allowfilter" is true. This feature is
currently in the "master" branch of Git, and as of the time of writing,
this feature is to be released in Git 2.17.

This is incomplete in that the filter-by-sparse-specification feature
also supported by Git is not included in this patch.

If a JGit server were to be patched with this commit, and a repository
on that server configured with RequestPolicy.ANY or
RequestPolicy.REACHABLE_COMMIT_TIP, a Git client built from the "master"
branch would be able to perform a partial clone.

Change-Id: If72b4b422c06ab432137e9e5272d353b14b73259
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>

1 files changed, 146 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 a8127abd36..17f21d6858 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
@@ -13,6 +13,7 @@ import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevBlob;
 import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevTree;
 import org.eclipse.jgit.transport.UploadPack.RequestPolicy;
 import org.eclipse.jgit.transport.resolver.ServiceNotAuthorizedException;
 import org.eclipse.jgit.transport.resolver.ServiceNotEnabledException;
@@ -170,4 +171,149 @@ public class UploadPackTest {
 					Collections.singletonList(new RefSpec(blob.name())));
 		}
 	}
+
+	@Test
+	public void testFetchWithBlobNoneFilter() throws Exception {
+		InMemoryRepository server2 = newRepo("server2");
+		TestRepository<InMemoryRepository> remote =
+				new TestRepository<>(server2);
+		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);
+
+		server2.getConfig().setBoolean("uploadpack", null, "allowfilter", true);
+
+		testProtocol = new TestProtocol<>(
+				new UploadPackFactory<Object>() {
+					@Override
+					public UploadPack create(Object req, Repository db)
+							throws ServiceNotEnabledException,
+							ServiceNotAuthorizedException {
+						UploadPack up = new UploadPack(db);
+						return up;
+					}
+				}, null);
+		uri = testProtocol.register(ctx, server2);
+
+		try (Transport tn = testProtocol.open(uri, client, "server2")) {
+			tn.setFilterBlobLimit(0);
+			tn.fetch(NullProgressMonitor.INSTANCE,
+					Collections.singletonList(new RefSpec(commit.name())));
+			assertTrue(client.hasObject(tree.toObjectId()));
+			assertFalse(client.hasObject(blob1.toObjectId()));
+			assertFalse(client.hasObject(blob2.toObjectId()));
+		}
+	}
+
+	@Test
+	public void testFetchWithBlobLimitFilter() throws Exception {
+		InMemoryRepository server2 = newRepo("server2");
+		TestRepository<InMemoryRepository> remote =
+				new TestRepository<>(server2);
+		RevBlob longBlob = remote.blob("foobar");
+		RevBlob shortBlob = remote.blob("fooba");
+		RevTree tree = remote.tree(
+				remote.file("1", longBlob), remote.file("2", shortBlob));
+		RevCommit commit = remote.commit(tree);
+		remote.update("master", commit);
+
+		server2.getConfig().setBoolean("uploadpack", null, "allowfilter", true);
+
+		testProtocol = new TestProtocol<>(
+				new UploadPackFactory<Object>() {
+					@Override
+					public UploadPack create(Object req, Repository db)
+							throws ServiceNotEnabledException,
+							ServiceNotAuthorizedException {
+						UploadPack up = new UploadPack(db);
+						return up;
+					}
+				}, null);
+		uri = testProtocol.register(ctx, server2);
+
+		try (Transport tn = testProtocol.open(uri, client, "server2")) {
+			tn.setFilterBlobLimit(5);
+			tn.fetch(NullProgressMonitor.INSTANCE,
+					Collections.singletonList(new RefSpec(commit.name())));
+			assertFalse(client.hasObject(longBlob.toObjectId()));
+			assertTrue(client.hasObject(shortBlob.toObjectId()));
+		}
+	}
+
+	@Test
+	public void testFetchWithBlobLimitFilterAndBitmaps() throws Exception {
+		InMemoryRepository server2 = newRepo("server2");
+		TestRepository<InMemoryRepository> remote =
+				new TestRepository<>(server2);
+		RevBlob longBlob = remote.blob("foobar");
+		RevBlob shortBlob = remote.blob("fooba");
+		RevTree tree = remote.tree(
+				remote.file("1", longBlob), remote.file("2", shortBlob));
+		RevCommit commit = remote.commit(tree);
+		remote.update("master", commit);
+
+		server2.getConfig().setBoolean("uploadpack", null, "allowfilter", true);
+
+		// generate bitmaps
+		new DfsGarbageCollector(server2).pack(null);
+		server2.scanForRepoChanges();
+
+		testProtocol = new TestProtocol<>(
+				new UploadPackFactory<Object>() {
+					@Override
+					public UploadPack create(Object req, Repository db)
+							throws ServiceNotEnabledException,
+							ServiceNotAuthorizedException {
+						UploadPack up = new UploadPack(db);
+						return up;
+					}
+				}, null);
+		uri = testProtocol.register(ctx, server2);
+
+		try (Transport tn = testProtocol.open(uri, client, "server2")) {
+			tn.setFilterBlobLimit(5);
+			tn.fetch(NullProgressMonitor.INSTANCE,
+					Collections.singletonList(new RefSpec(commit.name())));
+			assertFalse(client.hasObject(longBlob.toObjectId()));
+			assertTrue(client.hasObject(shortBlob.toObjectId()));
+		}
+	}
+
+	@Test
+	public void testFetchWithNonSupportingServer() throws Exception {
+		InMemoryRepository server2 = newRepo("server2");
+		TestRepository<InMemoryRepository> remote =
+				new TestRepository<>(server2);
+		RevBlob blob = remote.blob("foo");
+		RevTree tree = remote.tree(remote.file("1", blob));
+		RevCommit commit = remote.commit(tree);
+		remote.update("master", commit);
+
+		server2.getConfig().setBoolean("uploadpack", null, "allowfilter", false);
+
+		testProtocol = new TestProtocol<>(
+				new UploadPackFactory<Object>() {
+					@Override
+					public UploadPack create(Object req, Repository db)
+							throws ServiceNotEnabledException,
+							ServiceNotAuthorizedException {
+						UploadPack up = new UploadPack(db);
+						return up;
+					}
+				}, null);
+		uri = testProtocol.register(ctx, server2);
+
+		try (Transport tn = testProtocol.open(uri, client, "server2")) {
+			tn.setFilterBlobLimit(0);
+
+			thrown.expect(TransportException.class);
+			thrown.expectMessage("filter requires server to advertise that capability");
+
+			tn.fetch(NullProgressMonitor.INSTANCE,
+					Collections.singletonList(new RefSpec(commit.name())));
+		}
+	}
 }