Handle repo submodules for bare repositories.

Change-Id: Id028a7bc9600baf0f3e2316a1f4b99e53ccc746a
Signed-off-by: Yuxuan 'fishy' Wang <fishywang@google.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/gitrepo/RepoCommandTest.java

@@ -50,9 +50,11 @@ import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 
+import org.eclipse.jgit.api.CloneCommand;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.junit.RepositoryTestCase;
+import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Repository;
 import org.junit.Test;
 
@@ -213,6 +215,45 @@ public class RepoCommandTest extends RepositoryTestCase {
 		assertEquals("The destination file has expected content", "world", content);
 	}
 
+	@Test
+	public void testBareRepo() throws Exception {
+		Repository remoteDb = createBareRepository();
+		Repository tempDb = createWorkRepository();
+		StringBuilder xmlContent = new StringBuilder();
+		xmlContent.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n")
+			.append("<manifest>")
+			.append("<remote name=\"remote1\" fetch=\".\" />")
+			.append("<default revision=\"master\" remote=\"remote1\" />")
+			.append("<project path=\"foo\" name=\"")
+			.append(defaultUri)
+			.append("\" />")
+			.append("</manifest>");
+		JGitTestUtil.writeTrashFile(tempDb, "manifest.xml", xmlContent.toString());
+		RepoCommand command = new RepoCommand(remoteDb);
+		command.setPath(tempDb.getWorkTree().getAbsolutePath() + "/manifest.xml")
+			.setURI(rootUri)
+			.call();
+		// Clone it
+		File directory = createTempDirectory("testBareRepo");
+		CloneCommand clone = Git.cloneRepository();
+		clone.setDirectory(directory);
+		clone.setURI(remoteDb.getDirectory().toURI().toString());
+		Repository localDb = clone.call().getRepository();
+		// The .gitmodules file should exist
+		File gitmodules = new File(localDb.getWorkTree(), ".gitmodules");
+		assertTrue("The .gitmodules file exists", gitmodules.exists());
+		// The first line of .gitmodules file should be expected
+		BufferedReader reader = new BufferedReader(new FileReader(gitmodules));
+		String content = reader.readLine();
+		reader.close();
+		assertEquals("The first line of .gitmodules file is as expected.",
+				"[submodule \"foo\"]", content);
+		// The gitlink should be the same of remote head sha1
+		String gitlink = localDb.resolve(Constants.HEAD + ":foo").name();
+		String remote = defaultDb.resolve(Constants.HEAD).name();
+		assertEquals("The gitlink is same as remote head", remote, gitlink);
+	}
+
 	private void resolveRelativeUris() {
 		// Find the longest common prefix ends with "/" as rootUri.
 		defaultUri = defaultDb.getDirectory().toURI().toString();

org.eclipse.jgit/resources/org/eclipse/jgit/gitrepo/internal/RepoText.properties

@@ -1,5 +1,6 @@
 copyFileFailed=Error occurred during execution of copyfile rule.
 errorNoDefault=Error: no default remote in file {0}.
 errorParsingManifestFile=Error occurred during parsing manifest file {0}.
+errorRemoteUnavailable=Error remote {0} is unavailable.
 invalidManifest=Invalid manifest.
 repoCommitMessage=Added repo manifest.

org.eclipse.jgit/src/org/eclipse/jgit/gitrepo/RepoCommand.java

@@ -48,9 +48,11 @@ import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.channels.FileChannel;
+import java.nio.charset.Charset;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -58,15 +60,32 @@ import java.util.Map;
 import java.util.Set;
 
 import org.eclipse.jgit.api.AddCommand;
+import org.eclipse.jgit.api.LsRemoteCommand;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.GitCommand;
 import org.eclipse.jgit.api.SubmoduleAddCommand;
+import org.eclipse.jgit.api.errors.ConcurrentRefUpdateException;
 import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.dircache.DirCache;
+import org.eclipse.jgit.dircache.DirCacheBuilder;
+import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.gitrepo.internal.RepoText;
 import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.lib.CommitBuilder;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.FileMode;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectInserter;
+import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.ProgressMonitor;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefUpdate;
+import org.eclipse.jgit.lib.RefUpdate.Result;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
 
 import org.xml.sax.Attributes;
 import org.xml.sax.InputSource;
@@ -89,10 +108,46 @@ public class RepoCommand extends GitCommand<RevCommit> {
 	private String path;
 	private String uri;
 	private String groups;
+	private PersonIdent author;
+	private RemoteReader callback;
 
+	private List<Project> bareProjects;
 	private Git git;
 	private ProgressMonitor monitor;
 
+	/**
+	 * A callback to get head sha1 of a repository from its uri.
+	 *
+	 * We provided a default implementation {@link DefaultRemoteReader} to
+	 * use ls-remote command to read the sha1 from the repository. Callers may
+	 * have their own quicker implementation.
+	 */
+	public interface RemoteReader {
+		/**
+		 * Read a remote repository's HEAD sha1.
+		 *
+		 * @param uri
+		 *            The URI of the remote repository
+		 * @return the sha1 of the HEAD of the remote repository
+		 */
+		public ObjectId sha1(String uri) throws GitAPIException;
+	}
+
+	/** A default implementation of {@link RemoteReader} callback. */
+	public static class DefaultRemoteReader implements RemoteReader {
+		public ObjectId sha1(String uri) throws GitAPIException {
+			Collection<Ref> refs = Git
+					.lsRemoteRepository()
+					.setRemote(uri)
+					.call();
+			for (Ref ref : refs) {
+				if (Constants.HEAD.equals(ref.getName()))
+					return ref.getObjectId();
+			}
+			return null;
+		}
+	}
+
 	private static class CopyFile {
 		final String src;
 		final String dest;
@@ -293,6 +348,12 @@ public class RepoCommand extends GitCommand<RevCommit> {
 		}
 	}
 
+	private static class RemoteUnavailableException extends GitAPIException {
+		RemoteUnavailableException(String uri, Throwable cause) {
+			super(MessageFormat.format(RepoText.get().errorRemoteUnavailable, uri), cause);
+		}
+	}
+
 	/**
 	 * @param repo
 	 */
@@ -347,6 +408,32 @@ public class RepoCommand extends GitCommand<RevCommit> {
 		return this;
 	}
 
+	/**
+	 * Set the author/committer for the bare repository commit.
+	 *
+	 * For non-bare repositories, the current user will be used and this will be ignored.
+	 *
+	 * @param author
+	 * @return this command
+	 */
+	public RepoCommand setAuthor(final PersonIdent author) {
+		this.author = author;
+		return this;
+	}
+
+	/**
+	 * Set the GetHeadFromUri callback.
+	 *
+	 * This is only used in bare repositories.
+	 *
+	 * @param callback
+	 * @return this command
+	 */
+	public RepoCommand setRemoteReader(final RemoteReader callback) {
+		this.callback = callback;
+		return this;
+	}
+
 	@Override
 	public RevCommit call() throws GitAPIException {
 		checkCallable();
@@ -355,7 +442,15 @@ public class RepoCommand extends GitCommand<RevCommit> {
 		if (uri == null || uri.length() == 0)
 			throw new IllegalArgumentException(JGitText.get().uriNotConfigured);
 
-		git = new Git(repo);
+		if (repo.isBare()) {
+			bareProjects = new ArrayList<Project>();
+			if (author == null)
+				author = new PersonIdent(repo);
+			if (callback == null)
+				callback = new DefaultRemoteReader();
+		} else
+			git = new Git(repo);
+
 		XmlManifest manifest = new XmlManifest(this, path, uri, groups);
 		try {
 			manifest.read();
@@ -363,23 +458,115 @@ public class RepoCommand extends GitCommand<RevCommit> {
 			throw new ManifestErrorException(e);
 		}
 
-		return git
-			.commit()
-			.setMessage(RepoText.get().repoCommitMessage)
-			.call();
+		if (repo.isBare()) {
+			DirCache index = DirCache.newInCore();
+			DirCacheBuilder builder = index.builder();
+			ObjectInserter inserter = repo.newObjectInserter();
+			RevWalk rw = new RevWalk(repo);
+
+			try {
+				Config cfg = new Config();
+				for (Project proj : bareProjects) {
+					String name = proj.path;
+					String uri = proj.name;
+					cfg.setString("submodule", name, "path", name); //$NON-NLS-1$ //$NON-NLS-2$
+					cfg.setString("submodule", name, "url", uri); //$NON-NLS-1$ //$NON-NLS-2$
+					// create gitlink
+					final DirCacheEntry dcEntry = new DirCacheEntry(name);
+					ObjectId objectId;
+					try {
+						objectId = callback.sha1(uri);
+					} catch (GitAPIException e) {
+						// Something wrong getting the head sha1
+						throw new RemoteUnavailableException(uri, e);
+					} catch (IllegalArgumentException e) {
+						// The revision from the manifest is malformed.
+						throw new ManifestErrorException(e);
+					}
+					if (objectId == null)
+						throw new RemoteUnavailableException(uri, null);
+					dcEntry.setObjectId(objectId);
+					dcEntry.setFileMode(FileMode.GITLINK);
+					builder.add(dcEntry);
+				}
+				String content = cfg.toText();
+
+				// create a new DirCacheEntry for .gitmodules file.
+				final DirCacheEntry dcEntry = new DirCacheEntry(Constants.DOT_GIT_MODULES);
+				ObjectId objectId = inserter.insert(Constants.OBJ_BLOB,
+						content.getBytes(Constants.CHARACTER_ENCODING));
+				dcEntry.setObjectId(objectId);
+				dcEntry.setFileMode(FileMode.REGULAR_FILE);
+				builder.add(dcEntry);
+
+				builder.finish();
+				ObjectId treeId = index.writeTree(inserter);
+
+				// Create a Commit object, populate it and write it
+				ObjectId headId = repo.resolve(Constants.HEAD + "^{commit}"); //$NON-NLS-1$
+				CommitBuilder commit = new CommitBuilder();
+				commit.setTreeId(treeId);
+				if (headId != null)
+					commit.setParentIds(headId);
+				commit.setAuthor(author);
+				commit.setCommitter(author);
+				commit.setMessage(RepoText.get().repoCommitMessage);
+
+				ObjectId commitId = inserter.insert(commit);
+				inserter.flush();
+
+				RefUpdate ru = repo.updateRef(Constants.HEAD);
+				ru.setNewObjectId(commitId);
+				ru.setExpectedOldObjectId(headId != null ? headId : ObjectId.zeroId());
+				Result rc = ru.update(rw);
+
+				switch (rc) {
+					case NEW:
+					case FORCED:
+					case FAST_FORWARD:
+						// Successful. Do nothing.
+						break;
+					case REJECTED:
+					case LOCK_FAILURE:
+						throw new ConcurrentRefUpdateException(
+								JGitText.get().couldNotLockHEAD, ru.getRef(),
+								rc);
+					default:
+						throw new JGitInternalException(MessageFormat.format(
+								JGitText.get().updatingRefFailed,
+								Constants.HEAD, commitId.name(), rc));
+				}
+
+				return rw.parseCommit(commitId);
+			} catch (IOException e) {
+				throw new ManifestErrorException(e);
+			} finally {
+				rw.release();
+			}
+		} else {
+			return git
+				.commit()
+				.setMessage(RepoText.get().repoCommitMessage)
+				.call();
+		}
 	}
 
 	private void addSubmodule(String url, String name) throws SAXException {
-		SubmoduleAddCommand add = git
-			.submoduleAdd()
-			.setPath(name)
-			.setURI(url);
-		if (monitor != null)
-			add.setProgressMonitor(monitor);
-		try {
-			add.call();
-		} catch (GitAPIException e) {
-			throw new SAXException(e);
+		if (repo.isBare()) {
+			Project proj = new Project(url, name, null);
+			bareProjects.add(proj);
+		} else {
+			SubmoduleAddCommand add = git
+				.submoduleAdd()
+				.setPath(name)
+				.setURI(url);
+			if (monitor != null)
+				add.setProgressMonitor(monitor);
+			try {
+				add.call();
+			} catch (GitAPIException e) {
+				throw new SAXException(e);
+			}
 		}
 	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/gitrepo/internal/RepoText.java

@@ -62,6 +62,7 @@ public class RepoText extends TranslationBundle {
 	/***/ public String copyFileFailed;
 	/***/ public String errorNoDefault;
 	/***/ public String errorParsingManifestFile;
+	/***/ public String errorRemoteUnavailable;
 	/***/ public String invalidManifest;
 	/***/ public String repoCommitMessage;
 }