Fetch: add support for shallow

This adds support for shallow cloning. The CloneCommand and the
FetchCommand now have the new methods setDepth, setShallowSince and
addShallowExclude to tell the server that the client doesn't want to
download the complete history.

Bug: 475615
Change-Id: Ic80fb6efb5474543ae59be590ebe385bec21cc0d

1 files changed, 234 insertions, 1 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
index c928d2ad22..6053c8c568 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CloneCommandTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011, 2013 Chris Aniszczyk <caniszczyk@gmail.com> and others
+ * Copyright (C) 2011, 2022 Chris Aniszczyk <caniszczyk@gmail.com> and others
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Distribution License v. 1.0 which is available at
@@ -19,10 +19,14 @@ import static org.junit.Assert.fail;
 import java.io.File;
 import java.io.IOException;
 import java.net.URISyntaxException;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 import org.eclipse.jgit.api.ListBranchCommand.ListMode;
 import org.eclipse.jgit.api.errors.GitAPIException;
@@ -40,6 +44,7 @@ import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.StoredConfig;
 import org.eclipse.jgit.revwalk.RevBlob;
 import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevObject;
 import org.eclipse.jgit.submodule.SubmoduleStatus;
 import org.eclipse.jgit.submodule.SubmoduleStatusType;
 import org.eclipse.jgit.submodule.SubmoduleWalk;
@@ -895,6 +900,234 @@ public class CloneCommandTest extends RepositoryTestCase {
 		assertEquals("refs/heads/test-copy", git2.getRepository().getFullBranch());
 	}
 
+    @Test
+    public void testCloneRepositoryWithDepth() throws IOException, JGitInternalException, GitAPIException {
+		File directory = createTempDirectory("testCloneRepositoryWithDepth");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+        command.setDepth(1);
+		command.setBranchesToClone(Set.of("refs/heads/test"));
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+		List<RevCommit> log = StreamSupport.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(1, log.size());
+		RevCommit commit = log.get(0);
+		assertEquals(Set.of(commit.getId()),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals("Second commit", commit.getFullMessage());
+		assertEquals(0, commit.getParentCount());
+	}
+
+	@Test
+	public void testCloneRepositoryWithDepthAndAllBranches() throws IOException, JGitInternalException, GitAPIException {
+		File directory = createTempDirectory("testCloneRepositoryWithDepthAndAllBranches");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		command.setDepth(1);
+		command.setCloneAllBranches(true);
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+		List<RevCommit> log = StreamSupport.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(2, log.size());
+		assertEquals(log.stream().map(RevCommit::getId).collect(Collectors.toSet()),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals(List.of("Second commit", "Initial commit"),
+				log.stream().map(RevCommit::getFullMessage).collect(Collectors.toList()));
+		for (RevCommit commit : log) {
+			assertEquals(0, commit.getParentCount());
+		}
+	}
+
+	@Test
+	public void testCloneRepositoryWithDepth2() throws Exception {
+		RevCommit parent = tr.git().log().call().iterator().next();
+		RevCommit commit = tr.commit()
+				.parent(parent)
+				.message("Third commit")
+				.add("test.txt", "Hello world")
+				.create();
+		tr.update("refs/heads/test", commit);
+
+		File directory = createTempDirectory("testCloneRepositoryWithDepth2");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		command.setDepth(2);
+		command.setBranchesToClone(Set.of("refs/heads/test"));
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+		List<RevCommit> log = StreamSupport
+				.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(2, log.size());
+		assertEquals(Set.of(parent.getId()),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals(List.of("Third commit", "Second commit"), log.stream()
+				.map(RevCommit::getFullMessage).collect(Collectors.toList()));
+		assertEquals(List.of(Integer.valueOf(1), Integer.valueOf(0)),
+				log.stream().map(RevCommit::getParentCount)
+						.collect(Collectors.toList()));
+	}
+
+	@Test
+	public void testCloneRepositoryWithDepthAndFetch() throws Exception {
+		File directory = createTempDirectory("testCloneRepositoryWithDepthAndFetch");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		command.setDepth(1);
+		command.setBranchesToClone(Set.of("refs/heads/test"));
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+		RevCommit parent = tr.git().log().call().iterator().next();
+		RevCommit commit = tr.commit()
+				.parent(parent)
+				.message("Third commit")
+				.add("test.txt", "Hello world")
+				.create();
+		tr.update("refs/heads/test", commit);
+
+		git2.fetch().call();
+
+		List<RevCommit> log = StreamSupport
+				.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(2, log.size());
+		assertEquals(Set.of(parent.getId()),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals(List.of("Third commit", "Second commit"), log.stream()
+				.map(RevCommit::getFullMessage).collect(Collectors.toList()));
+		assertEquals(List.of(Integer.valueOf(1), Integer.valueOf(0)),
+				log.stream().map(RevCommit::getParentCount)
+						.collect(Collectors.toList()));
+	}
+
+	@Test
+	public void testCloneRepositoryWithDepthAndFetchWithDepth() throws Exception {
+		File directory = createTempDirectory("testCloneRepositoryWithDepthAndFetchWithDepth");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		command.setDepth(1);
+		command.setBranchesToClone(Set.of("refs/heads/test"));
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+		RevCommit parent = tr.git().log().call().iterator().next();
+		RevCommit commit = tr.commit()
+				.parent(parent)
+				.message("Third commit")
+				.add("test.txt", "Hello world")
+				.create();
+		tr.update("refs/heads/test", commit);
+
+		git2.fetch().setDepth(1).call();
+
+		List<RevCommit> log = StreamSupport
+				.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(2, log.size());
+		assertEquals(
+				log.stream().map(RevObject::getId).collect(Collectors.toSet()),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals(List.of("Third commit", "Second commit"), log.stream()
+				.map(RevCommit::getFullMessage).collect(Collectors.toList()));
+		assertEquals(List.of(Integer.valueOf(0), Integer.valueOf(0)),
+				log.stream().map(RevCommit::getParentCount)
+						.collect(Collectors.toList()));
+	}
+
+	@Test
+	public void testCloneRepositoryWithDepthAndFetchUnshallow() throws Exception {
+		File directory = createTempDirectory("testCloneRepositoryWithDepthAndFetchUnshallow");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		command.setDepth(1);
+		command.setBranchesToClone(Set.of("refs/heads/test"));
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+		git2.fetch().setUnshallow(true).call();
+
+		List<RevCommit> log = StreamSupport
+				.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(2, log.size());
+		assertEquals(Set.of(),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals(List.of("Second commit", "Initial commit"), log.stream()
+				.map(RevCommit::getFullMessage).collect(Collectors.toList()));
+		assertEquals(List.of(Integer.valueOf(1), Integer.valueOf(0)),
+				log.stream().map(RevCommit::getParentCount)
+						.collect(Collectors.toList()));
+	}
+
+    @Test
+	public void testCloneRepositoryWithShallowSince() throws Exception {
+		RevCommit commit = tr.commit()
+				.parent(tr.git().log().call().iterator().next())
+				.message("Third commit").add("test.txt", "Hello world")
+				.create();
+		tr.update("refs/heads/test", commit);
+
+        File directory = createTempDirectory("testCloneRepositoryWithShallowSince");
+        CloneCommand command = Git.cloneRepository();
+        command.setDirectory(directory);
+        command.setURI(fileUri());
+        command.setShallowSince(Instant.ofEpochSecond(commit.getCommitTime()));
+        command.setBranchesToClone(Set.of("refs/heads/test"));
+        Git git2 = command.call();
+        addRepoToClose(git2.getRepository());
+
+		List<RevCommit> log = StreamSupport
+				.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(1, log.size());
+		assertEquals(Set.of(commit.getId()),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals("Third commit", log.get(0).getFullMessage());
+		assertEquals(0, log.get(0).getParentCount());
+    }
+
+	@Test
+	public void testCloneRepositoryWithShallowExclude() throws Exception {
+		RevCommit parent = tr.git().log().call().iterator().next();
+		tr.update("refs/heads/test",
+				tr.commit()
+					.parent(parent)
+					.message("Third commit")
+					.add("test.txt", "Hello world")
+					.create());
+
+		File directory = createTempDirectory("testCloneRepositoryWithShallowExclude");
+		CloneCommand command = Git.cloneRepository();
+		command.setDirectory(directory);
+		command.setURI(fileUri());
+		command.addShallowExclude(parent.getId());
+		command.setBranchesToClone(Set.of("refs/heads/test"));
+		Git git2 = command.call();
+		addRepoToClose(git2.getRepository());
+
+		List<RevCommit> log = StreamSupport
+				.stream(git2.log().all().call().spliterator(), false)
+				.collect(Collectors.toList());
+		assertEquals(1, log.size());
+		RevCommit commit = log.get(0);
+		assertEquals(Set.of(commit.getId()),
+				git2.getRepository().getObjectDatabase().getShallowCommits());
+		assertEquals("Third commit", commit.getFullMessage());
+		assertEquals(0, commit.getParentCount());
+	}
+
 	private void assertTagOption(Repository repo, TagOpt expectedTagOption)
 			throws URISyntaxException {
 		RemoteConfig remoteConfig = new RemoteConfig(