Move commit and tag formatting to CommitBuilder, TagBuilder

These objects should be responsible for their own formatting,
rather than delegating it to some obtuse type called ObjectInserter.

While we are at it, simplify the way we insert these into a database.
Passing in the type and calling format in application code turned
out to be a huge mistake in terms of ease-of-use of the insert API.

Change-Id: Id5bb95ee56aa2a002243e9b7853b84ec8df1d7bf
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/TestRepository.java

 		c.setMessage("");
 		ObjectId id;
 		try {
-			id = inserter.insert(Constants.OBJ_COMMIT, inserter.format(c));
+			id = inserter.insert(c);
 			inserter.flush();
 		} finally {
 			inserter.release();
 		t.setMessage("");
 		ObjectId id;
 		try {
-			id = inserter.insert(Constants.OBJ_TAG, inserter.format(t));
+			id = inserter.insert(t);
 			inserter.flush();
 		} finally {
 			inserter.release();
 				ObjectId commitId;
 				try {
 					c.setTreeId(tree.writeTree(inserter));
-					commitId = inserter.insert(Constants.OBJ_COMMIT, inserter
-							.format(c));
+					commitId = inserter.insert(c);
 					inserter.flush();
 				} finally {
 					inserter.release();

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Tag.java

 			tag.setTagger(new PersonIdent(db));
 			tag.setMessage(message.replaceAll("\r", ""));
 			tag.setTag(shortName);
-			id = inserter.insert(Constants.OBJ_TAG, inserter.format(tag));
+			id = inserter.insert(tag);
 			inserter.flush();
 		} finally {
 			inserter.release();

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/debug/RebuildCommitGraph.java

 				newc.setCommitter(newc.getAuthor());
 				newc.setParentIds(newParents);
 				newc.setMessage("ORIGINAL " + t.oldId.name() + "\n");
-				t.newId = oi.insert(Constants.OBJ_COMMIT,oi.format(newc));
+				t.newId = oi.insert(newc);
 				rewrites.put(t.oldId, t.newId);
 				pm.update(1);
 			}

org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/CherryPickTest.java

 package org.eclipse.jgit.merge;
 
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
-import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
 
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheBuilder;
 		c.setCommitter(c.getAuthor());
 		c.setParentIds(parentIds);
 		c.setMessage("Tree " + c.getTreeId().name());
-		ObjectId id = odi.insert(OBJ_COMMIT, odi.format(c));
+		ObjectId id = odi.insert(c);
 		odi.flush();
 		return id;
 	}

org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/SimpleMergeTest.java

 package org.eclipse.jgit.merge;
 
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
-import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
 
 import java.io.IOException;
 
 		c.setCommitter(c.getAuthor());
 		c.setParentIds(parentIds);
 		c.setMessage("Tree " + c.getTreeId().name());
-		ObjectId id = odi.insert(OBJ_COMMIT, odi.format(c));
+		ObjectId id = odi.insert(c);
 		odi.flush();
 		return id;
 	}

org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevCommitParseTest.java

 		src.setCommitter(committer);
 		src.setMessage("Test commit\n\nThis is a test.\n");
 
-		RevCommit p = RevCommit.parse(fmt.format(src));
+		RevCommit p = RevCommit.parse(src.format());
 		assertEquals(src.getTreeId(), p.getTree());
 		assertEquals(0, p.getParentCount());
 		assertEquals(author, p.getAuthorIdent());

org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevTagParseTest.java

 		src.setTag("a.test");
 		src.setMessage("Test tag\n\nThis is a test.\n");
 
-		RevTag p = RevTag.parse(fmt.format(src));
+		RevTag p = RevTag.parse(src.format());
 		assertEquals(src.getObjectId(), p.getObject());
 		assertEquals(committer, p.getTaggerIdent());
 		assertEquals("a.test", p.getTagName());

org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/T0003_Basic.java

 
 	}
 
-	private ObjectId insertCommit(final CommitBuilder commit) throws IOException,
+	private ObjectId insertCommit(final CommitBuilder builder) throws IOException,
 			UnsupportedEncodingException {
 		ObjectInserter oi = db.newObjectInserter();
 		try {
-			ObjectId id = oi.insert(Constants.OBJ_COMMIT, oi.format(commit));
+			ObjectId id = oi.insert(builder);
 			oi.flush();
-			commit.setCommitId(id);
 			return id;
 		} finally {
 			oi.release();
 			UnsupportedEncodingException {
 		ObjectInserter oi = db.newObjectInserter();
 		try {
-			ObjectId id = oi.insert(Constants.OBJ_TAG, oi.format(tag));
+			ObjectId id = oi.insert(tag);
 			oi.flush();
-			tag.setTagId(id);
 			return id;
 		} finally {
 			oi.release();

org.eclipse.jgit/src/org/eclipse/jgit/api/CommitCommand.java

 
 					commit.setParentIds(parents);
 					commit.setTreeId(indexTreeId);
-					ObjectId commitId = odi.insert(Constants.OBJ_COMMIT, odi
-							.format(commit));
+					ObjectId commitId = odi.insert(commit);
 					odi.flush();
 
 					RevWalk revWalk = new RevWalk(repo);

org.eclipse.jgit/src/org/eclipse/jgit/lib/CommitBuilder.java

 
 package org.eclipse.jgit.lib;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.UnsupportedEncodingException;
 import java.nio.charset.Charset;
 import java.util.List;
 
 public class CommitBuilder {
 	private static final ObjectId[] EMPTY_OBJECTID_LIST = new ObjectId[0];
 
+	private static final byte[] htree = Constants.encodeASCII("tree");
+
+	private static final byte[] hparent = Constants.encodeASCII("parent");
+
+	private static final byte[] hauthor = Constants.encodeASCII("author");
+
+	private static final byte[] hcommitter = Constants.encodeASCII("committer");
+
+	private static final byte[] hencoding = Constants.encodeASCII("encoding");
+
 	private ObjectId commitId;
 
 	private ObjectId treeId;
 		return encoding;
 	}
 
+	/**
+	 * Format this builder's state as a commit object.
+	 *
+	 * As a side effect, {@link #getCommitId()} will be populated with the
+	 * proper ObjectId for the formatted content.
+	 *
+	 * @return this object in the canonical commit format, suitable for storage
+	 *         in a repository.
+	 * @throws UnsupportedEncodingException
+	 *             the encoding specified by {@link #getEncoding()} is not
+	 *             supported by this Java runtime.
+	 */
+	public byte[] format() throws UnsupportedEncodingException {
+		return format(new ObjectInserter.Formatter());
+	}
+
+	/**
+	 * Format this builder's state as a commit object.
+	 *
+	 * As a side effect, {@link #getCommitId()} will be populated with the
+	 * proper ObjectId for the formatted content.
+	 *
+	 * @param oi
+	 *            the inserter whose formatting support will be reused. The
+	 *            inserter itself is not affected, and the commit is not
+	 *            actually inserted into the repository.
+	 * @return this object in the canonical commit format, suitable for storage
+	 *         in a repository.
+	 * @throws UnsupportedEncodingException
+	 *             the encoding specified by {@link #getEncoding()} is not
+	 *             supported by this Java runtime.
+	 */
+	public byte[] format(ObjectInserter oi) throws UnsupportedEncodingException {
+		ByteArrayOutputStream os = new ByteArrayOutputStream();
+		OutputStreamWriter w = new OutputStreamWriter(os, getEncoding());
+		try {
+			os.write(htree);
+			os.write(' ');
+			getTreeId().copyTo(os);
+			os.write('\n');
+
+			for (ObjectId p : getParentIds()) {
+				os.write(hparent);
+				os.write(' ');
+				p.copyTo(os);
+				os.write('\n');
+			}
+
+			os.write(hauthor);
+			os.write(' ');
+			w.write(getAuthor().toExternalString());
+			w.flush();
+			os.write('\n');
+
+			os.write(hcommitter);
+			os.write(' ');
+			w.write(getCommitter().toExternalString());
+			w.flush();
+			os.write('\n');
+
+			if (getEncoding() != Constants.CHARSET) {
+				os.write(hencoding);
+				os.write(' ');
+				os.write(Constants.encodeASCII(getEncoding().name()));
+				os.write('\n');
+			}
+
+			os.write('\n');
+
+			if (getMessage() != null) {
+				w.write(getMessage());
+				w.flush();
+			}
+		} catch (IOException err) {
+			// This should never occur, the only way to get it above is
+			// for the ByteArrayOutputStream to throw, but it doesn't.
+			//
+			throw new RuntimeException(err);
+		}
+
+		byte[] content = os.toByteArray();
+		setCommitId(oi.idFor(Constants.OBJ_COMMIT, content));
+		return content;
+	}
+
 	@Override
 	public String toString() {
 		StringBuilder r = new StringBuilder();

org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectInserter.java

 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.OutputStreamWriter;
-import java.io.UnsupportedEncodingException;
-import java.nio.charset.Charset;
 import java.security.MessageDigest;
 import java.text.MessageFormat;
 
  * otherwise making the returned ObjectIds visible to other code.
  */
 public abstract class ObjectInserter {
-	private static final byte[] htree = Constants.encodeASCII("tree");
-
-	private static final byte[] hparent = Constants.encodeASCII("parent");
-
-	private static final byte[] hauthor = Constants.encodeASCII("author");
-
-	private static final byte[] hcommitter = Constants.encodeASCII("committer");
-
-	private static final byte[] hencoding = Constants.encodeASCII("encoding");
-
 	/** An inserter that can be used for formatting and id generation only. */
 	public static class Formatter extends ObjectInserter {
 		@Override
 		return ObjectId.fromRaw(md.digest());
 	}
 
+	/**
+	 * Insert a single commit into the store, returning its unique name.
+	 *
+	 * As a side effect, {@link CommitBuilder#getCommitId()} will also be
+	 * populated with the returned ObjectId.
+	 *
+	 * @param builder
+	 *            the builder containing the proposed commit's data.
+	 * @return the name of the commit object.
+	 * @throws IOException
+	 *             the object could not be stored.
+	 */
+	public final ObjectId insert(CommitBuilder builder) throws IOException {
+		return insert(Constants.OBJ_COMMIT, builder.format(this));
+	}
+
+	/**
+	 * Insert a single annotated tag into the store, returning its unique name.
+	 *
+	 * As a side effect, {@link TagBuilder#getTagId()} will also be populated
+	 * with the returned ObjectId.
+	 *
+	 * @param builder
+	 *            the builder containing the proposed tag's data.
+	 * @return the name of the tag object.
+	 * @throws IOException
+	 *             the object could not be stored.
+	 */
+	public final ObjectId insert(TagBuilder builder) throws IOException {
+		return insert(Constants.OBJ_TAG, builder.format(this));
+	}
+
 	/**
 	 * Insert a single object into the store, returning its unique name.
 	 *
 		}
 		return o.toByteArray();
 	}
-
-	/**
-	 * Format a Commit in canonical format.
-	 *
-	 * @param commit
-	 *            the commit object to format
-	 * @return canonical encoding of the commit object.
-	 * @throws UnsupportedEncodingException
-	 *             the commit's chosen encoding isn't supported on this JVM.
-	 */
-	public final byte[] format(CommitBuilder commit)
-			throws UnsupportedEncodingException {
-		Charset encoding = commit.getEncoding();
-		ByteArrayOutputStream os = new ByteArrayOutputStream();
-		OutputStreamWriter w = new OutputStreamWriter(os, encoding);
-		try {
-			os.write(htree);
-			os.write(' ');
-			commit.getTreeId().copyTo(os);
-			os.write('\n');
-
-			for (ObjectId p : commit.getParentIds()) {
-				os.write(hparent);
-				os.write(' ');
-				p.copyTo(os);
-				os.write('\n');
-			}
-
-			os.write(hauthor);
-			os.write(' ');
-			w.write(commit.getAuthor().toExternalString());
-			w.flush();
-			os.write('\n');
-
-			os.write(hcommitter);
-			os.write(' ');
-			w.write(commit.getCommitter().toExternalString());
-			w.flush();
-			os.write('\n');
-
-			if (encoding != Constants.CHARSET) {
-				os.write(hencoding);
-				os.write(' ');
-				os.write(Constants.encodeASCII(encoding.name()));
-				os.write('\n');
-			}
-
-			os.write('\n');
-
-			if (commit.getMessage() != null) {
-				w.write(commit.getMessage());
-				w.flush();
-			}
-		} catch (IOException err) {
-			// This should never occur, the only way to get it above is
-			// for the ByteArrayOutputStream to throw, but it doesn't.
-			//
-			throw new RuntimeException(err);
-		}
-		return os.toByteArray();
-	}
-
-	/**
-	 * Format a Tag in canonical format.
-	 *
-	 * @param tag
-	 *            the tag object to format
-	 * @return canonical encoding of the tag object.
-	 */
-	public final byte[] format(TagBuilder tag) {
-		ByteArrayOutputStream os = new ByteArrayOutputStream();
-		OutputStreamWriter w = new OutputStreamWriter(os, Constants.CHARSET);
-		try {
-			w.write("object ");
-			tag.getObjectId().copyTo(w);
-			w.write('\n');
-
-			w.write("type ");
-			w.write(Constants.typeString(tag.getObjectType()));
-			w.write("\n");
-
-			w.write("tag ");
-			w.write(tag.getTag());
-			w.write("\n");
-
-			if (tag.getTagger() != null) {
-				w.write("tagger ");
-				w.write(tag.getTagger().toExternalString());
-				w.write('\n');
-			}
-
-			w.write('\n');
-			if (tag.getMessage() != null)
-				w.write(tag.getMessage());
-			w.close();
-		} catch (IOException err) {
-			// This should never occur, the only way to get it above is
-			// for the ByteArrayOutputStream to throw, but it doesn't.
-			//
-			throw new RuntimeException(err);
-		}
-		return os.toByteArray();
-	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectWriter.java

 package org.eclipse.jgit.lib;
 
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
-import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
-import static org.eclipse.jgit.lib.Constants.OBJ_TAG;
 import static org.eclipse.jgit.lib.Constants.OBJ_TREE;
 
 import java.io.File;
 	 */
 	public ObjectId writeCommit(CommitBuilder commit) throws IOException {
 		try {
-			ObjectId id = inserter.insert(OBJ_COMMIT, inserter.format(commit));
+			ObjectId id = inserter.insert(commit);
 			inserter.flush();
 			return id;
 		} finally {
 	 */
 	public ObjectId writeTag(TagBuilder tag) throws IOException {
 		try {
-			ObjectId id = inserter.insert(OBJ_TAG, inserter.format(tag));
+			ObjectId id = inserter.insert(tag);
 			inserter.flush();
 			return id;
 		} finally {

org.eclipse.jgit/src/org/eclipse/jgit/lib/TagBuilder.java

 
 package org.eclipse.jgit.lib;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+
 import org.eclipse.jgit.revwalk.RevObject;
 
 /**
 		tagId = null;
 	}
 
+	/**
+	 * Format this builder's state as an annotated tag object.
+	 *
+	 * As a side effect, {@link #getTagId()} will be populated with the proper
+	 * ObjectId for the formatted content.
+	 *
+	 * @return this object in the canonical annotated tag format, suitable for
+	 *         storage in a repository.
+	 */
+	public byte[] format() {
+		return format(new ObjectInserter.Formatter());
+	}
+
+	/**
+	 * Format this builder's state as an annotated tag object.
+	 *
+	 * As a side effect, {@link #getTagId()} will be populated with the proper
+	 * ObjectId for the formatted content.
+	 *
+	 * @param oi
+	 *            the inserter whose formatting support will be reused. The
+	 *            inserter itself is not affected, and the annotated tag is not
+	 *            actually inserted into the repository.
+	 * @return this object in the canonical annotated tag format, suitable for
+	 *         storage in a repository.
+	 */
+	public byte[] format(ObjectInserter oi) {
+		ByteArrayOutputStream os = new ByteArrayOutputStream();
+		OutputStreamWriter w = new OutputStreamWriter(os, Constants.CHARSET);
+		try {
+			w.write("object ");
+			getObjectId().copyTo(w);
+			w.write('\n');
+
+			w.write("type ");
+			w.write(Constants.typeString(getObjectType()));
+			w.write("\n");
+
+			w.write("tag ");
+			w.write(getTag());
+			w.write("\n");
+
+			if (getTagger() != null) {
+				w.write("tagger ");
+				w.write(getTagger().toExternalString());
+				w.write('\n');
+			}
+
+			w.write('\n');
+			if (getMessage() != null)
+				w.write(getMessage());
+			w.close();
+		} catch (IOException err) {
+			// This should never occur, the only way to get it above is
+			// for the ByteArrayOutputStream to throw, but it doesn't.
+			//
+			throw new RuntimeException(err);
+		}
+
+		byte[] content = os.toByteArray();
+		setTagId(oi.idFor(Constants.OBJ_TAG, content));
+		return content;
+	}
+
 	@Override
 	public String toString() {
 		StringBuilder r = new StringBuilder();