RepoCommand.RemoteReader: Add method to read contents and mode of file

The RepoCommand.RemoteReader interface doesn't offer access to the mode
of a file. Caller can only default to mark the copied objects as regular
files, losing e.g. the executable bit (if set).

Add a new method readFileWithMode that returns the contents and mode of
the remote file. It supersedes the readFile method, that is marked as
deprecated.

Now callers can set correctly the file mode of the copied file.

Change-Id: I8fce01e4bc5707434c0cbc4aebbae1b6b64756f0
Signed-off-by: Ivan Frade <ifrade@google.com>

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

@@ -56,13 +56,16 @@ import java.io.IOException;
 import java.net.URI;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.text.MessageFormat;
 import java.util.HashMap;
 import java.util.Map;
 
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.api.errors.InvalidRefNameException;
 import org.eclipse.jgit.api.errors.InvalidRemoteException;
-import org.eclipse.jgit.api.errors.RefNotFoundException;
+import org.eclipse.jgit.gitrepo.RepoCommand.RemoteFile;
+import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.junit.RepositoryTestCase;
 import org.eclipse.jgit.lib.BlobBasedConfig;
@@ -74,6 +77,7 @@ import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.storage.file.FileBasedConfig;
+import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.util.FS;
 import org.junit.Test;
 
@@ -142,6 +146,7 @@ public class RepoCommandTest extends RepositoryTestCase {
 
 	static class IndexedRepos implements RepoCommand.RemoteReader {
 		Map<String, Repository> uriRepoMap;
+
 		IndexedRepos() {
 			uriRepoMap = new HashMap<>();
 		}
@@ -170,19 +175,21 @@ public class RepoCommandTest extends RepositoryTestCase {
 		}
 
 		@Override
-		public byte[] readFile(String uri, String refName, String path)
+		public RemoteFile readFileWithMode(String uri, String ref, String path)
 				throws GitAPIException, IOException {
 			Repository repo = uriRepoMap.get(uri);
-
+			ObjectId refCommitId = sha1(uri, ref);
-			String idStr = refName + ":" + path;
+			if (refCommitId == null) {
-			ObjectId id = repo.resolve(idStr);
+				throw new InvalidRefNameException(MessageFormat
-			if (id == null) {
+						.format(JGitText.get().refNotResolved, ref));
-				throw new RefNotFoundException(
+			}
-					String.format("repo %s does not have %s", repo.toString(), idStr));
+			RevCommit commit = repo.parseCommit(refCommitId);
-			}
+			TreeWalk tw = TreeWalk.forPath(repo, path, commit.getTree());
-			try (ObjectReader reader = repo.newObjectReader()) {
+
-				return reader.open(id).getCachedBytes(Integer.MAX_VALUE);
+			// TODO(ifrade): Cope better with big files (e.g. using InputStream
-			}
+			// instead of byte[])
+			return new RemoteFile(tw.getObjectReader().open(tw.getObjectId(0))
+					.getCachedBytes(Integer.MAX_VALUE), tw.getFileMode(0));
 		}
 	}
 

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

@@ -59,12 +59,14 @@ import java.util.Objects;
 import java.util.StringJoiner;
 import java.util.TreeMap;
 
+import org.eclipse.jgit.annotations.NonNull;
 import org.eclipse.jgit.annotations.Nullable;
 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.InvalidRefNameException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheBuilder;
@@ -80,7 +82,6 @@ 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.ObjectReader;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
@@ -90,6 +91,7 @@ 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.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.util.FileUtils;
 
 /**
@@ -144,7 +146,9 @@ public class RepoCommand extends GitCommand<RevCommit> {
 		 * @param uri
 		 *            The URI of the remote repository
 		 * @param ref
-		 *            The ref (branch/tag/etc.) to read
+		 *            Name of the ref to lookup. May be a short-hand form, e.g.
+		 *            "master" which is is automatically expanded to
+		 *            "refs/heads/master" if "refs/heads/master" already exists.
 		 * @return the sha1 of the remote repository, or null if the ref does
 		 *         not exist.
 		 * @throws GitAPIException
@@ -165,13 +169,93 @@ public class RepoCommand extends GitCommand<RevCommit> {
 		 * @throws GitAPIException
 		 * @throws IOException
 		 * @since 3.5
+		 *
+		 * @deprecated Use {@link #readFileWithMode(String, String, String)}
+		 *             instead
+		 */
+		@Deprecated
+		public default byte[] readFile(String uri, String ref, String path)
+				throws GitAPIException, IOException {
+			return readFileWithMode(uri, ref, path).getContents();
+		}
+
+		/**
+		 * Read contents and mode (i.e. permissions) of the file from a remote
+		 * repository.
+		 *
+		 * @param uri
+		 *            The URI of the remote repository
+		 * @param ref
+		 *            Name of the ref to lookup. May be a short-hand form, e.g.
+		 *            "master" which is is automatically expanded to
+		 *            "refs/heads/master" if "refs/heads/master" already exists.
+		 * @param path
+		 *            The relative path (inside the repo) to the file to read
+		 * @return The contents and file mode of the file in the given
+		 *         repository and branch. Never null.
+		 * @throws GitAPIException
+		 *             If the ref have an invalid or ambiguous name, or it does
+		 *             not exist in the repository,
+		 * @throws IOException
+		 *             If the object does not exist or is too large
+		 * @since 5.2
 		 */
-		public byte[] readFile(String uri, String ref, String path)
+		@NonNull
+		public RemoteFile readFileWithMode(String uri, String ref, String path)
 				throws GitAPIException, IOException;
 	}
 
+	/**
+	 * Read-only view of contents and file mode (i.e. permissions) for a file in
+	 * a remote repository.
+	 *
+	 * @since 5.2
+	 */
+	public static final class RemoteFile {
+		@NonNull
+		private final byte[] contents;
+
+		@NonNull
+		private final FileMode fileMode;
+
+		/**
+		 * @param contents
+		 *            Raw contents of the file.
+		 * @param fileMode
+		 *            Git file mode for this file (e.g. executable or regular)
+		 */
+		public RemoteFile(@NonNull byte[] contents,
+				@NonNull FileMode fileMode) {
+			this.contents = Objects.requireNonNull(contents);
+			this.fileMode = Objects.requireNonNull(fileMode);
+		}
+
+		/**
+		 * Contents of the file.
+		 * <p>
+		 * Callers who receive this reference must not modify its contents (as
+		 * it can point to internal cached data).
+		 *
+		 * @return Raw contents of the file. Do not modify it.
+		 */
+		@NonNull
+		public byte[] getContents() {
+			return contents;
+		}
+
+		/**
+		 * @return Git file mode for this file (e.g. executable or regular)
+		 */
+		@NonNull
+		public FileMode getFileMode() {
+			return fileMode;
+		}
+
+	}
+
 	/** A default implementation of {@link RemoteReader} callback. */
 	public static class DefaultRemoteReader implements RemoteReader {
+
 		@Override
 		public ObjectId sha1(String uri, String ref) throws GitAPIException {
 			Map<String, Ref> map = Git
@@ -183,38 +267,30 @@ public class RepoCommand extends GitCommand<RevCommit> {
 		}
 
 		@Override
-		public byte[] readFile(String uri, String ref, String path)
+		public RemoteFile readFileWithMode(String uri, String ref, String path)
 				throws GitAPIException, IOException {
 			File dir = FileUtils.createTempDir("jgit_", ".git", null); //$NON-NLS-1$ //$NON-NLS-2$
 			try (Git git = Git.cloneRepository().setBare(true).setDirectory(dir)
 					.setURI(uri).call()) {
-				return readFileFromRepo(git.getRepository(), ref, path);
+				Repository repo = git.getRepository();
+				ObjectId refCommitId = sha1(uri, ref);
+				if (refCommitId == null) {
+					throw new InvalidRefNameException(MessageFormat
+							.format(JGitText.get().refNotResolved, ref));
+				}
+				RevCommit commit = repo.parseCommit(refCommitId);
+				TreeWalk tw = TreeWalk.forPath(repo, path, commit.getTree());
+
+				// TODO(ifrade): Cope better with big files (e.g. using
+				// InputStream instead of byte[])
+				return new RemoteFile(
+						tw.getObjectReader().open(tw.getObjectId(0))
+								.getCachedBytes(Integer.MAX_VALUE),
+						tw.getFileMode(0));
 			} finally {
 				FileUtils.delete(dir, FileUtils.RECURSIVE);
 			}
 		}
-
-		/**
-		 * Read a file from the repository
-		 *
-		 * @param repo
-		 *            The repository containing the file
-		 * @param ref
-		 *            The ref (branch/tag/etc.) to read
-		 * @param path
-		 *            The relative path (inside the repo) to the file to read
-		 * @return the file's content
-		 * @throws GitAPIException
-		 * @throws IOException
-		 * @since 3.5
-		 */
-		protected byte[] readFileFromRepo(Repository repo,
-				String ref, String path) throws GitAPIException, IOException {
-			try (ObjectReader reader = repo.newObjectReader()) {
-				ObjectId oid = repo.resolve(ref + ":" + path); //$NON-NLS-1$
-				return reader.open(oid).getBytes(Integer.MAX_VALUE);
-			}
-		}
 	}
 
 	@SuppressWarnings("serial")