org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java - jgit - Git at Google

 /*
  * Copyright (C) 2008-2009, Google Inc.
  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
  * under the terms of the Eclipse Distribution License v1.0 which
  * accompanies this distribution, is reproduced below, and is
  * available at http://www.eclipse.org/org/documents/edl-v10.php
  *
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or
  * without modification, are permitted provided that the following
  * conditions are met:
  *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  *
  * - Redistributions in binary form must reproduce the above
  *   copyright notice, this list of conditions and the following
  *   disclaimer in the documentation and/or other materials provided
  *   with the distribution.
  *
  * - Neither the name of the Eclipse Foundation, Inc. nor the
  *   names of its contributors may be used to endorse or promote
  *   products derived from this software without specific prior
  *   written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 package org.eclipse.jgit.revwalk;

 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;

 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Commit;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.MutableObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.util.RawParseUtils;

 /** A commit reference to a commit in the DAG. */
 public class RevCommit extends RevObject {
 	static final RevCommit[] NO_PARENTS = {};

 	private RevTree tree;

 	RevCommit[] parents;

 	int commitTime; // An int here for performance, overflows in 2038

 	int inDegree;

 	private byte[] buffer;

 	/**
 	 * Create a new commit reference.
 	 *
 	 * @param id
 	 *            object name for the commit.
 	 */
 	protected RevCommit(final AnyObjectId id) {
 		super(id);
 	}

 	@Override
 	void parseHeaders(final RevWalk walk) throws MissingObjectException,
 			IncorrectObjectTypeException, IOException {
 		parseCanonical(walk, loadCanonical(walk));
 	}

 	@Override
 	void parseBody(final RevWalk walk) throws MissingObjectException,
 			IncorrectObjectTypeException, IOException {
 		if (buffer == null) {
 			buffer = loadCanonical(walk);
 			if ((flags & PARSED) == 0)
 				parseCanonical(walk, buffer);
 		}
 	}

 	void parseCanonical(final RevWalk walk, final byte[] raw) {
 		final MutableObjectId idBuffer = walk.idBuffer;
 		idBuffer.fromString(raw, 5);
 		tree = walk.lookupTree(idBuffer);

 		int ptr = 46;
 		if (parents == null) {
 			RevCommit[] pList = new RevCommit[1];
 			int nParents = 0;
 			for (;;) {
 				if (raw[ptr] != 'p')
 					break;
 				idBuffer.fromString(raw, ptr + 7);
 				final RevCommit p = walk.lookupCommit(idBuffer);
 				if (nParents == 0)
 					pList[nParents++] = p;
 				else if (nParents == 1) {
 					pList = new RevCommit[] { pList[0], p };
 					nParents = 2;
 				} else {
 					if (pList.length <= nParents) {
 						RevCommit[] old = pList;
 						pList = new RevCommit[pList.length + 32];
 						System.arraycopy(old, 0, pList, 0, nParents);
 					}
 					pList[nParents++] = p;
 				}
 				ptr += 48;
 			}
 			if (nParents != pList.length) {
 				RevCommit[] old = pList;
 				pList = new RevCommit[nParents];
 				System.arraycopy(old, 0, pList, 0, nParents);
 			}
 			parents = pList;
 		}

 		// extract time from "committer "
 		ptr = RawParseUtils.committer(raw, ptr);
 		if (ptr > 0) {
 			ptr = RawParseUtils.nextLF(raw, ptr, '>');

 			// In 2038 commitTime will overflow unless it is changed to long.
 			commitTime = RawParseUtils.parseBase10(raw, ptr, null);
 		}

 		if (walk.isRetainBody())
 			buffer = raw;
 		flags |= PARSED;
 	}

 	@Override
 	public final int getType() {
 		return Constants.OBJ_COMMIT;
 	}

 	static void carryFlags(RevCommit c, final int carry) {
 		for (;;) {
 			final RevCommit[] pList = c.parents;
 			if (pList == null)
 				return;
 			final int n = pList.length;
 			if (n == 0)
 				return;

 			for (int i = 1; i < n; i++) {
 				final RevCommit p = pList[i];
 				if ((p.flags & carry) == carry)
 					continue;
 				p.flags |= carry;
 				carryFlags(p, carry);
 			}

 			c = pList[0];
 			if ((c.flags & carry) == carry)
 				return;
 			c.flags |= carry;
 		}
 	}

 	/**
 	 * Carry a RevFlag set on this commit to its parents.
 	 * <p>
 	 * If this commit is parsed, has parents, and has the supplied flag set on
 	 * it we automatically add it to the parents, grand-parents, and so on until
 	 * an unparsed commit or a commit with no parents is discovered. This
 	 * permits applications to force a flag through the history chain when
 	 * necessary.
 	 *
 	 * @param flag
 	 *            the single flag value to carry back onto parents.
 	 */
 	public void carry(final RevFlag flag) {
 		final int carry = flags & flag.mask;
 		if (carry != 0)
 			carryFlags(this, carry);
 	}

 	/**
 	 * Time from the "committer " line of the buffer.
 	 *
 	 * @return time, expressed as seconds since the epoch.
 	 */
 	public final int getCommitTime() {
 		return commitTime;
 	}

 	/**
 	 * Parse this commit buffer for display.
 	 *
 	 * @param walk
 	 *            revision walker owning this reference.
 	 * @return parsed commit.
 	 */
 	public final Commit asCommit(final RevWalk walk) {
 		return new Commit(walk.db, this, buffer);
 	}

 	/**
 	 * Get a reference to this commit's tree.
 	 *
 	 * @return tree of this commit.
 	 */
 	public final RevTree getTree() {
 		return tree;
 	}

 	/**
 	 * Get the number of parent commits listed in this commit.
 	 *
 	 * @return number of parents; always a positive value but can be 0.
 	 */
 	public final int getParentCount() {
 		return parents.length;
 	}

 	/**
 	 * Get the nth parent from this commit's parent list.
 	 *
 	 * @param nth
 	 *            parent index to obtain. Must be in the range 0 through
 	 *            {@link #getParentCount()}-1.
 	 * @return the specified parent.
 	 * @throws ArrayIndexOutOfBoundsException
 	 *             an invalid parent index was specified.
 	 */
 	public final RevCommit getParent(final int nth) {
 		return parents[nth];
 	}

 	/**
 	 * Obtain an array of all parents (<b>NOTE - THIS IS NOT A COPY</b>).
 	 * <p>
 	 * This method is exposed only to provide very fast, efficient access to
 	 * this commit's parent list. Applications relying on this list should be
 	 * very careful to ensure they do not modify its contents during their use
 	 * of it.
 	 *
 	 * @return the array of parents.
 	 */
 	public final RevCommit[] getParents() {
 		return parents;
 	}

 	/**
 	 * Obtain the raw unparsed commit body (<b>NOTE - THIS IS NOT A COPY</b>).
 	 * <p>
 	 * This method is exposed only to provide very fast, efficient access to
 	 * this commit's message buffer within a RevFilter. Applications relying on
 	 * this buffer should be very careful to ensure they do not modify its
 	 * contents during their use of it.
 	 *
 	 * @return the raw unparsed commit body. This is <b>NOT A COPY</b>.
 	 *         Altering the contents of this buffer may alter the walker's
 	 *         knowledge of this commit, and the results it produces.
 	 */
 	public final byte[] getRawBuffer() {
 		return buffer;
 	}

 	/**
 	 * Parse the author identity from the raw buffer.
 	 * <p>
 	 * This method parses and returns the content of the author line, after
 	 * taking the commit's character set into account and decoding the author
 	 * name and email address. This method is fairly expensive and produces a
 	 * new PersonIdent instance on each invocation. Callers should invoke this
 	 * method only if they are certain they will be outputting the result, and
 	 * should cache the return value for as long as necessary to use all
 	 * information from it.
 	 * <p>
 	 * RevFilter implementations should try to use {@link RawParseUtils} to scan
 	 * the {@link #getRawBuffer()} instead, as this will allow faster evaluation
 	 * of commits.
 	 *
 	 * @return identity of the author (name, email) and the time the commit was
 	 *         made by the author; null if no author line was found.
 	 */
 	public final PersonIdent getAuthorIdent() {
 		final byte[] raw = buffer;
 		final int nameB = RawParseUtils.author(raw, 0);
 		if (nameB < 0)
 			return null;
 		return RawParseUtils.parsePersonIdent(raw, nameB);
 	}

 	/**
 	 * Parse the committer identity from the raw buffer.
 	 * <p>
 	 * This method parses and returns the content of the committer line, after
 	 * taking the commit's character set into account and decoding the committer
 	 * name and email address. This method is fairly expensive and produces a
 	 * new PersonIdent instance on each invocation. Callers should invoke this
 	 * method only if they are certain they will be outputting the result, and
 	 * should cache the return value for as long as necessary to use all
 	 * information from it.
 	 * <p>
 	 * RevFilter implementations should try to use {@link RawParseUtils} to scan
 	 * the {@link #getRawBuffer()} instead, as this will allow faster evaluation
 	 * of commits.
 	 *
 	 * @return identity of the committer (name, email) and the time the commit
 	 *         was made by the committer; null if no committer line was found.
 	 */
 	public final PersonIdent getCommitterIdent() {
 		final byte[] raw = buffer;
 		final int nameB = RawParseUtils.committer(raw, 0);
 		if (nameB < 0)
 			return null;
 		return RawParseUtils.parsePersonIdent(raw, nameB);
 	}

 	/**
 	 * Parse the complete commit message and decode it to a string.
 	 * <p>
 	 * This method parses and returns the message portion of the commit buffer,
 	 * after taking the commit's character set into account and decoding the
 	 * buffer using that character set. This method is a fairly expensive
 	 * operation and produces a new string on each invocation.
 	 *
 	 * @return decoded commit message as a string. Never null.
 	 */
 	public final String getFullMessage() {
 		final byte[] raw = buffer;
 		final int msgB = RawParseUtils.commitMessage(raw, 0);
 		if (msgB < 0)
 			return "";
 		final Charset enc = RawParseUtils.parseEncoding(raw);
 		return RawParseUtils.decode(enc, raw, msgB, raw.length);
 	}

 	/**
 	 * Parse the commit message and return the first "line" of it.
 	 * <p>
 	 * The first line is everything up to the first pair of LFs. This is the
 	 * "oneline" format, suitable for output in a single line display.
 	 * <p>
 	 * This method parses and returns the message portion of the commit buffer,
 	 * after taking the commit's character set into account and decoding the
 	 * buffer using that character set. This method is a fairly expensive
 	 * operation and produces a new string on each invocation.
 	 *
 	 * @return decoded commit message as a string. Never null. The returned
 	 *         string does not contain any LFs, even if the first paragraph
 	 *         spanned multiple lines. Embedded LFs are converted to spaces.
 	 */
 	public final String getShortMessage() {
 		final byte[] raw = buffer;
 		final int msgB = RawParseUtils.commitMessage(raw, 0);
 		if (msgB < 0)
 			return "";

 		final Charset enc = RawParseUtils.parseEncoding(raw);
 		final int msgE = RawParseUtils.endOfParagraph(raw, msgB);
 		String str = RawParseUtils.decode(enc, raw, msgB, msgE);
 		if (hasLF(raw, msgB, msgE))
 			str = str.replace('\n', ' ');
 		return str;
 	}

 	static boolean hasLF(final byte[] r, int b, final int e) {
 		while (b < e)
 			if (r[b++] == '\n')
 				return true;
 		return false;
 	}

 	/**
 	 * Determine the encoding of the commit message buffer.
 	 * <p>
 	 * Locates the "encoding" header (if present) and then returns the proper
 	 * character set to apply to this buffer to evaluate its contents as
 	 * character data.
 	 * <p>
 	 * If no encoding header is present, {@link Constants#CHARSET} is assumed.
 	 *
 	 * @return the preferred encoding of {@link #getRawBuffer()}.
 	 */
 	public final Charset getEncoding() {
 		return RawParseUtils.parseEncoding(buffer);
 	}

 	/**
 	 * Parse the footer lines (e.g. "Signed-off-by") for machine processing.
 	 * <p>
 	 * This method splits all of the footer lines out of the last paragraph of
 	 * the commit message, providing each line as a key-value pair, ordered by
 	 * the order of the line's appearance in the commit message itself.
 	 * <p>
 	 * A footer line's key must match the pattern {@code ^[A-Za-z0-9-]+:}, while
 	 * the value is free-form, but must not contain an LF. Very common keys seen
 	 * in the wild are:
 	 * <ul>
 	 * <li>{@code Signed-off-by} (agrees to Developer Certificate of Origin)
 	 * <li>{@code Acked-by} (thinks change looks sane in context)
 	 * <li>{@code Reported-by} (originally found the issue this change fixes)
 	 * <li>{@code Tested-by} (validated change fixes the issue for them)
 	 * <li>{@code CC}, {@code Cc} (copy on all email related to this change)
 	 * <li>{@code Bug} (link to project's bug tracking system)
 	 * </ul>
 	 *
 	 * @return ordered list of footer lines; empty list if no footers found.
 	 */
 	public final List<FooterLine> getFooterLines() {
 		final byte[] raw = buffer;
 		int ptr = raw.length - 1;
 		while (raw[ptr] == '\n') // trim any trailing LFs, not interesting
 			ptr--;

 		final int msgB = RawParseUtils.commitMessage(raw, 0);
 		final ArrayList<FooterLine> r = new ArrayList<FooterLine>(4);
 		final Charset enc = getEncoding();
 		for (;;) {
 			ptr = RawParseUtils.prevLF(raw, ptr);
 			if (ptr <= msgB)
 				break; // Don't parse commit headers as footer lines.

 			final int keyStart = ptr + 2;
 			if (raw[keyStart] == '\n')
 				break; // Stop at first paragraph break, no footers above it.

 			final int keyEnd = RawParseUtils.endOfFooterLineKey(raw, keyStart);
 			if (keyEnd < 0)
 				continue; // Not a well formed footer line, skip it.

 			// Skip over the ': *' at the end of the key before the value.
 			//
 			int valStart = keyEnd + 1;
 			while (valStart < raw.length && raw[valStart] == ' ')
 				valStart++;

 			// Value ends at the LF, and does not include it.
 			//
 			int valEnd = RawParseUtils.nextLF(raw, valStart);
 			if (raw[valEnd - 1] == '\n')
 				valEnd--;

 			r.add(new FooterLine(raw, enc, keyStart, keyEnd, valStart, valEnd));
 		}
 		Collections.reverse(r);
 		return r;
 	}

 	/**
 	 * Get the values of all footer lines with the given key.
 	 *
 	 * @param keyName
 	 *            footer key to find values of, case insensitive.
 	 * @return values of footers with key of {@code keyName}, ordered by their
 	 *         order of appearance. Duplicates may be returned if the same
 	 *         footer appeared more than once. Empty list if no footers appear
 	 *         with the specified key, or there are no footers at all.
 	 * @see #getFooterLines()
 	 */
 	public final List<String> getFooterLines(final String keyName) {
 		return getFooterLines(new FooterKey(keyName));
 	}

 	/**
 	 * Get the values of all footer lines with the given key.
 	 *
 	 * @param keyName
 	 *            footer key to find values of, case insensitive.
 	 * @return values of footers with key of {@code keyName}, ordered by their
 	 *         order of appearance. Duplicates may be returned if the same
 	 *         footer appeared more than once. Empty list if no footers appear
 	 *         with the specified key, or there are no footers at all.
 	 * @see #getFooterLines()
 	 */
 	public final List<String> getFooterLines(final FooterKey keyName) {
 		final List<FooterLine> src = getFooterLines();
 		if (src.isEmpty())
 			return Collections.emptyList();
 		final ArrayList<String> r = new ArrayList<String>(src.size());
 		for (final FooterLine f : src) {
 			if (f.matches(keyName))
 				r.add(f.getValue());
 		}
 		return r;
 	}

 	/**
 	 * Reset this commit to allow another RevWalk with the same instances.
 	 * <p>
 	 * Subclasses <b>must</b> call <code>super.reset()</code> to ensure the
 	 * basic information can be correctly cleared out.
 	 */
 	public void reset() {
 		inDegree = 0;
 	}

 	final void disposeBody() {
 		buffer = null;
 	}

 	@Override
 	public String toString() {
 		final StringBuilder s = new StringBuilder();
 		s.append(Constants.typeString(getType()));
 		s.append(' ');
 		s.append(name());
 		s.append(' ');
 		s.append(commitTime);
 		s.append(' ');
 		appendCoreFlags(s);
 		return s.toString();
 	}
 }
	/*
	* Copyright (C) 2008-2009, Google Inc.
	* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
	* and other copyright owners as documented in the project's IP log.
	*
	* This program and the accompanying materials are made available
	* under the terms of the Eclipse Distribution License v1.0 which
	* accompanies this distribution, is reproduced below, and is
	* available at http://www.eclipse.org/org/documents/edl-v10.php
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* - Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* - Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials provided
	* with the distribution.
	*
	* - Neither the name of the Eclipse Foundation, Inc. nor the
	* names of its contributors may be used to endorse or promote
	* products derived from this software without specific prior
	* written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
	* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
	* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	package org.eclipse.jgit.revwalk;

	import java.io.IOException;
	import java.nio.charset.Charset;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.List;

	import org.eclipse.jgit.errors.IncorrectObjectTypeException;
	import org.eclipse.jgit.errors.MissingObjectException;
	import org.eclipse.jgit.lib.AnyObjectId;
	import org.eclipse.jgit.lib.Commit;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.MutableObjectId;
	import org.eclipse.jgit.lib.PersonIdent;
	import org.eclipse.jgit.util.RawParseUtils;

	/** A commit reference to a commit in the DAG. */
	public class RevCommit extends RevObject {
	static final RevCommit[] NO_PARENTS = {};

	private RevTree tree;

	RevCommit[] parents;

	int commitTime; // An int here for performance, overflows in 2038

	int inDegree;

	private byte[] buffer;

	/**
	* Create a new commit reference.
	*
	* @param id
	* object name for the commit.
	*/
	protected RevCommit(final AnyObjectId id) {
	super(id);
	}

	@Override
	void parseHeaders(final RevWalk walk) throws MissingObjectException,
	IncorrectObjectTypeException, IOException {
	parseCanonical(walk, loadCanonical(walk));
	}

	@Override
	void parseBody(final RevWalk walk) throws MissingObjectException,
	IncorrectObjectTypeException, IOException {
	if (buffer == null) {
	buffer = loadCanonical(walk);
	if ((flags & PARSED) == 0)
	parseCanonical(walk, buffer);
	}
	}

	void parseCanonical(final RevWalk walk, final byte[] raw) {
	final MutableObjectId idBuffer = walk.idBuffer;
	idBuffer.fromString(raw, 5);
	tree = walk.lookupTree(idBuffer);

	int ptr = 46;
	if (parents == null) {
	RevCommit[] pList = new RevCommit[1];
	int nParents = 0;
	for (;;) {
	if (raw[ptr] != 'p')
	break;
	idBuffer.fromString(raw, ptr + 7);
	final RevCommit p = walk.lookupCommit(idBuffer);
	if (nParents == 0)
	pList[nParents++] = p;
	else if (nParents == 1) {
	pList = new RevCommit[] { pList[0], p };
	nParents = 2;
	} else {
	if (pList.length <= nParents) {
	RevCommit[] old = pList;
	pList = new RevCommit[pList.length + 32];
	System.arraycopy(old, 0, pList, 0, nParents);
	}
	pList[nParents++] = p;
	}
	ptr += 48;
	}
	if (nParents != pList.length) {
	RevCommit[] old = pList;
	pList = new RevCommit[nParents];
	System.arraycopy(old, 0, pList, 0, nParents);
	}
	parents = pList;
	}

	// extract time from "committer "
	ptr = RawParseUtils.committer(raw, ptr);
	if (ptr > 0) {
	ptr = RawParseUtils.nextLF(raw, ptr, '>');

	// In 2038 commitTime will overflow unless it is changed to long.
	commitTime = RawParseUtils.parseBase10(raw, ptr, null);
	}

	if (walk.isRetainBody())
	buffer = raw;
	flags \|= PARSED;
	}

	@Override
	public final int getType() {
	return Constants.OBJ_COMMIT;
	}

	static void carryFlags(RevCommit c, final int carry) {
	for (;;) {
	final RevCommit[] pList = c.parents;
	if (pList == null)
	return;
	final int n = pList.length;
	if (n == 0)
	return;

	for (int i = 1; i < n; i++) {
	final RevCommit p = pList[i];
	if ((p.flags & carry) == carry)
	continue;
	p.flags \|= carry;
	carryFlags(p, carry);
	}

	c = pList[0];
	if ((c.flags & carry) == carry)
	return;
	c.flags \|= carry;
	}
	}

	/**
	* Carry a RevFlag set on this commit to its parents.
	* <p>
	* If this commit is parsed, has parents, and has the supplied flag set on
	* it we automatically add it to the parents, grand-parents, and so on until
	* an unparsed commit or a commit with no parents is discovered. This
	* permits applications to force a flag through the history chain when
	* necessary.
	*
	* @param flag
	* the single flag value to carry back onto parents.
	*/
	public void carry(final RevFlag flag) {
	final int carry = flags & flag.mask;
	if (carry != 0)
	carryFlags(this, carry);
	}

	/**
	* Time from the "committer " line of the buffer.
	*
	* @return time, expressed as seconds since the epoch.
	*/
	public final int getCommitTime() {
	return commitTime;
	}

	/**
	* Parse this commit buffer for display.
	*
	* @param walk
	* revision walker owning this reference.
	* @return parsed commit.
	*/
	public final Commit asCommit(final RevWalk walk) {
	return new Commit(walk.db, this, buffer);
	}

	/**
	* Get a reference to this commit's tree.
	*
	* @return tree of this commit.
	*/
	public final RevTree getTree() {
	return tree;
	}

	/**
	* Get the number of parent commits listed in this commit.
	*
	* @return number of parents; always a positive value but can be 0.
	*/
	public final int getParentCount() {
	return parents.length;
	}

	/**
	* Get the nth parent from this commit's parent list.
	*
	* @param nth
	* parent index to obtain. Must be in the range 0 through
	* {@link #getParentCount()}-1.
	* @return the specified parent.
	* @throws ArrayIndexOutOfBoundsException
	* an invalid parent index was specified.
	*/
	public final RevCommit getParent(final int nth) {
	return parents[nth];
	}

	/**
	* Obtain an array of all parents (<b>NOTE - THIS IS NOT A COPY</b>).
	* <p>
	* This method is exposed only to provide very fast, efficient access to
	* this commit's parent list. Applications relying on this list should be
	* very careful to ensure they do not modify its contents during their use
	* of it.
	*
	* @return the array of parents.
	*/
	public final RevCommit[] getParents() {
	return parents;
	}

	/**
	* Obtain the raw unparsed commit body (<b>NOTE - THIS IS NOT A COPY</b>).
	* <p>
	* This method is exposed only to provide very fast, efficient access to
	* this commit's message buffer within a RevFilter. Applications relying on
	* this buffer should be very careful to ensure they do not modify its
	* contents during their use of it.
	*
	* @return the raw unparsed commit body. This is <b>NOT A COPY</b>.
	* Altering the contents of this buffer may alter the walker's
	* knowledge of this commit, and the results it produces.
	*/
	public final byte[] getRawBuffer() {
	return buffer;
	}

	/**
	* Parse the author identity from the raw buffer.
	* <p>
	* This method parses and returns the content of the author line, after
	* taking the commit's character set into account and decoding the author
	* name and email address. This method is fairly expensive and produces a
	* new PersonIdent instance on each invocation. Callers should invoke this
	* method only if they are certain they will be outputting the result, and
	* should cache the return value for as long as necessary to use all
	* information from it.
	* <p>
	* RevFilter implementations should try to use {@link RawParseUtils} to scan
	* the {@link #getRawBuffer()} instead, as this will allow faster evaluation
	* of commits.
	*
	* @return identity of the author (name, email) and the time the commit was
	* made by the author; null if no author line was found.
	*/
	public final PersonIdent getAuthorIdent() {
	final byte[] raw = buffer;
	final int nameB = RawParseUtils.author(raw, 0);
	if (nameB < 0)
	return null;
	return RawParseUtils.parsePersonIdent(raw, nameB);
	}

	/**
	* Parse the committer identity from the raw buffer.
	* <p>
	* This method parses and returns the content of the committer line, after
	* taking the commit's character set into account and decoding the committer
	* name and email address. This method is fairly expensive and produces a
	* new PersonIdent instance on each invocation. Callers should invoke this
	* method only if they are certain they will be outputting the result, and
	* should cache the return value for as long as necessary to use all
	* information from it.
	* <p>
	* RevFilter implementations should try to use {@link RawParseUtils} to scan
	* the {@link #getRawBuffer()} instead, as this will allow faster evaluation
	* of commits.
	*
	* @return identity of the committer (name, email) and the time the commit
	* was made by the committer; null if no committer line was found.
	*/
	public final PersonIdent getCommitterIdent() {
	final byte[] raw = buffer;
	final int nameB = RawParseUtils.committer(raw, 0);
	if (nameB < 0)
	return null;
	return RawParseUtils.parsePersonIdent(raw, nameB);
	}

	/**
	* Parse the complete commit message and decode it to a string.
	* <p>
	* This method parses and returns the message portion of the commit buffer,
	* after taking the commit's character set into account and decoding the
	* buffer using that character set. This method is a fairly expensive
	* operation and produces a new string on each invocation.
	*
	* @return decoded commit message as a string. Never null.
	*/
	public final String getFullMessage() {
	final byte[] raw = buffer;
	final int msgB = RawParseUtils.commitMessage(raw, 0);
	if (msgB < 0)
	return "";
	final Charset enc = RawParseUtils.parseEncoding(raw);
	return RawParseUtils.decode(enc, raw, msgB, raw.length);
	}

	/**
	* Parse the commit message and return the first "line" of it.
	* <p>
	* The first line is everything up to the first pair of LFs. This is the
	* "oneline" format, suitable for output in a single line display.
	* <p>
	* This method parses and returns the message portion of the commit buffer,
	* after taking the commit's character set into account and decoding the
	* buffer using that character set. This method is a fairly expensive
	* operation and produces a new string on each invocation.
	*
	* @return decoded commit message as a string. Never null. The returned
	* string does not contain any LFs, even if the first paragraph
	* spanned multiple lines. Embedded LFs are converted to spaces.
	*/
	public final String getShortMessage() {
	final byte[] raw = buffer;
	final int msgB = RawParseUtils.commitMessage(raw, 0);
	if (msgB < 0)
	return "";

	final Charset enc = RawParseUtils.parseEncoding(raw);
	final int msgE = RawParseUtils.endOfParagraph(raw, msgB);
	String str = RawParseUtils.decode(enc, raw, msgB, msgE);
	if (hasLF(raw, msgB, msgE))
	str = str.replace('\n', ' ');
	return str;
	}

	static boolean hasLF(final byte[] r, int b, final int e) {
	while (b < e)
	if (r[b++] == '\n')
	return true;
	return false;
	}

	/**
	* Determine the encoding of the commit message buffer.
	* <p>
	* Locates the "encoding" header (if present) and then returns the proper
	* character set to apply to this buffer to evaluate its contents as
	* character data.
	* <p>
	* If no encoding header is present, {@link Constants#CHARSET} is assumed.
	*
	* @return the preferred encoding of {@link #getRawBuffer()}.
	*/
	public final Charset getEncoding() {
	return RawParseUtils.parseEncoding(buffer);
	}

	/**
	* Parse the footer lines (e.g. "Signed-off-by") for machine processing.
	* <p>
	* This method splits all of the footer lines out of the last paragraph of
	* the commit message, providing each line as a key-value pair, ordered by
	* the order of the line's appearance in the commit message itself.
	* <p>
	* A footer line's key must match the pattern {@code ^[A-Za-z0-9-]+:}, while
	* the value is free-form, but must not contain an LF. Very common keys seen
	* in the wild are:
	* <ul>
	* <li>{@code Signed-off-by} (agrees to Developer Certificate of Origin)
	* <li>{@code Acked-by} (thinks change looks sane in context)
	* <li>{@code Reported-by} (originally found the issue this change fixes)
	* <li>{@code Tested-by} (validated change fixes the issue for them)
	* <li>{@code CC}, {@code Cc} (copy on all email related to this change)
	* <li>{@code Bug} (link to project's bug tracking system)
	* </ul>
	*
	* @return ordered list of footer lines; empty list if no footers found.
	*/
	public final List<FooterLine> getFooterLines() {
	final byte[] raw = buffer;
	int ptr = raw.length - 1;
	while (raw[ptr] == '\n') // trim any trailing LFs, not interesting
	ptr--;

	final int msgB = RawParseUtils.commitMessage(raw, 0);
	final ArrayList<FooterLine> r = new ArrayList<FooterLine>(4);
	final Charset enc = getEncoding();
	for (;;) {
	ptr = RawParseUtils.prevLF(raw, ptr);
	if (ptr <= msgB)
	break; // Don't parse commit headers as footer lines.

	final int keyStart = ptr + 2;
	if (raw[keyStart] == '\n')
	break; // Stop at first paragraph break, no footers above it.

	final int keyEnd = RawParseUtils.endOfFooterLineKey(raw, keyStart);
	if (keyEnd < 0)
	continue; // Not a well formed footer line, skip it.

	// Skip over the ': *' at the end of the key before the value.
	//
	int valStart = keyEnd + 1;
	while (valStart < raw.length && raw[valStart] == ' ')
	valStart++;

	// Value ends at the LF, and does not include it.
	//
	int valEnd = RawParseUtils.nextLF(raw, valStart);
	if (raw[valEnd - 1] == '\n')
	valEnd--;

	r.add(new FooterLine(raw, enc, keyStart, keyEnd, valStart, valEnd));
	}
	Collections.reverse(r);
	return r;
	}

	/**
	* Get the values of all footer lines with the given key.
	*
	* @param keyName
	* footer key to find values of, case insensitive.
	* @return values of footers with key of {@code keyName}, ordered by their
	* order of appearance. Duplicates may be returned if the same
	* footer appeared more than once. Empty list if no footers appear
	* with the specified key, or there are no footers at all.
	* @see #getFooterLines()
	*/
	public final List<String> getFooterLines(final String keyName) {
	return getFooterLines(new FooterKey(keyName));
	}

	/**
	* Get the values of all footer lines with the given key.
	*
	* @param keyName
	* footer key to find values of, case insensitive.
	* @return values of footers with key of {@code keyName}, ordered by their
	* order of appearance. Duplicates may be returned if the same
	* footer appeared more than once. Empty list if no footers appear
	* with the specified key, or there are no footers at all.
	* @see #getFooterLines()
	*/
	public final List<String> getFooterLines(final FooterKey keyName) {
	final List<FooterLine> src = getFooterLines();
	if (src.isEmpty())
	return Collections.emptyList();
	final ArrayList<String> r = new ArrayList<String>(src.size());
	for (final FooterLine f : src) {
	if (f.matches(keyName))
	r.add(f.getValue());
	}
	return r;
	}

	/**
	* Reset this commit to allow another RevWalk with the same instances.
	* <p>
	* Subclasses <b>must</b> call <code>super.reset()</code> to ensure the
	* basic information can be correctly cleared out.
	*/
	public void reset() {
	inDegree = 0;
	}

	final void disposeBody() {
	buffer = null;
	}

	@Override
	public String toString() {
	final StringBuilder s = new StringBuilder();
	s.append(Constants.typeString(getType()));
	s.append(' ');
	s.append(name());
	s.append(' ');
	s.append(commitTime);
	s.append(' ');
	appendCoreFlags(s);
	return s.toString();
	}
	}