org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java - jgit - Git at Google

 /*
  * Copyright (C) 2010, Google Inc.
  * Copyright (C) 2006, 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
  * Copyright (C) 2008, 2021, Shawn O. Pearce <spearce@spearce.org> 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
  * https://www.eclipse.org/org/documents/edl-v10.php.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */

 package org.eclipse.jgit.pgm;

 import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;

 import org.eclipse.jgit.diff.DiffFormatter;
 import org.eclipse.jgit.diff.RawText;
 import org.eclipse.jgit.diff.RawTextComparator;
 import org.eclipse.jgit.diff.RenameDetector;
 import org.eclipse.jgit.errors.LargeObjectException;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.GpgConfig;
 import org.eclipse.jgit.lib.SignatureVerifier.SignatureVerification;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.SignatureVerifiers;
 import org.eclipse.jgit.notes.NoteMap;
 import org.eclipse.jgit.pgm.internal.CLIText;
 import org.eclipse.jgit.pgm.internal.VerificationUtils;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevTree;
 import org.eclipse.jgit.util.GitDateFormatter;
 import org.eclipse.jgit.util.GitDateFormatter.Format;
 import org.kohsuke.args4j.Option;

 @Command(common = true, usage = "usage_viewCommitHistory")
 class Log extends RevWalkTextBuiltin {

 	private GitDateFormatter dateFormatter = new GitDateFormatter(
 			Format.DEFAULT);

 	private DiffFormatter diffFmt;

 	private Map<AnyObjectId, Set<Ref>> allRefsByPeeledObjectId;

 	private Map<String, NoteMap> noteMaps;

 	private boolean showNameOnly = false;

 	private boolean showNameAndStatusOnly = false;

 	@Option(name="--decorate", usage="usage_showRefNamesMatchingCommits")
 	private boolean decorate;

 	@Option(name = "--no-standard-notes", usage = "usage_noShowStandardNotes")
 	private boolean noStandardNotes;

 	private List<String> additionalNoteRefs = new ArrayList<>();

 	@Option(name = "--show-notes", usage = "usage_showNotes", metaVar = "metaVar_ref")
 	void addAdditionalNoteRef(String notesRef) {
 		additionalNoteRefs.add(notesRef);
 	}

 	@Option(name = "--show-signature", usage = "usage_showSignature")
 	private boolean showSignature;

 	@Option(name = "--date", usage = "usage_date")
 	void dateFormat(String date) {
 		if (date.toLowerCase(Locale.ROOT).equals(date))
 			date = date.toUpperCase(Locale.ROOT);
 		dateFormatter = new GitDateFormatter(Format.valueOf(date));
 	}

 	// BEGIN -- Options shared with Diff
 	@Option(name = "-p", usage = "usage_showPatch")
 	boolean showPatch;

 	@Option(name = "-M", usage = "usage_detectRenames")
 	private Boolean detectRenames;

 	@Option(name = "--no-renames", usage = "usage_noRenames")
 	void noRenames(@SuppressWarnings("unused") boolean on) {
 		detectRenames = Boolean.FALSE;
 	}

 	@Option(name = "-l", usage = "usage_renameLimit")
 	private Integer renameLimit;

 	@Option(name = "--name-status", usage = "usage_nameStatus")
 	void nameAndStatusOnly(boolean on) {
 		if (showNameOnly) {
 			throw new IllegalArgumentException(
 					CLIText.get().cannotUseNameStatusOnlyAndNameOnly);
 		}
 		showNameAndStatusOnly = on;
 	}

 	@Option(name = "--name-only", usage = "usage_nameOnly")
 	void nameOnly(boolean on) {
 		if (showNameAndStatusOnly) {
 			throw new IllegalArgumentException(
 					CLIText.get().cannotUseNameStatusOnlyAndNameOnly);
 		}
 		showNameOnly = on;
 	}

 	@Option(name = "--ignore-space-at-eol")
 	void ignoreSpaceAtEol(@SuppressWarnings("unused") boolean on) {
 		diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_TRAILING);
 	}

 	@Option(name = "--ignore-leading-space")
 	void ignoreLeadingSpace(@SuppressWarnings("unused") boolean on) {
 		diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_LEADING);
 	}

 	@Option(name = "-b", aliases = { "--ignore-space-change" })
 	void ignoreSpaceChange(@SuppressWarnings("unused") boolean on) {
 		diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_CHANGE);
 	}

 	@Option(name = "-w", aliases = { "--ignore-all-space" })
 	void ignoreAllSpace(@SuppressWarnings("unused") boolean on) {
 		diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_ALL);
 	}

 	@Option(name = "-U", aliases = { "--unified" }, metaVar = "metaVar_linesOfContext")
 	void unified(int lines) {
 		diffFmt.setContext(lines);
 	}

 	@Option(name = "--abbrev", metaVar = "metaVar_n")
 	void abbrev(int lines) {
 		diffFmt.setAbbreviationLength(lines);
 	}

 	@Option(name = "--full-index")
 	void abbrev(@SuppressWarnings("unused") boolean on) {
 		diffFmt.setAbbreviationLength(Constants.OBJECT_ID_STRING_LENGTH);
 	}

 	@Option(name = "--src-prefix", usage = "usage_srcPrefix")
 	void sourcePrefix(String path) {
 		diffFmt.setOldPrefix(path);
 	}

 	@Option(name = "--dst-prefix", usage = "usage_dstPrefix")
 	void dstPrefix(String path) {
 		diffFmt.setNewPrefix(path);
 	}

 	@Option(name = "--no-prefix", usage = "usage_noPrefix")
 	void noPrefix(@SuppressWarnings("unused") boolean on) {
 		diffFmt.setOldPrefix(""); //$NON-NLS-1$
 		diffFmt.setNewPrefix(""); //$NON-NLS-1$
 	}

 	// END -- Options shared with Diff


 	private GpgConfig config;

 	Log() {
 		dateFormatter = new GitDateFormatter(Format.DEFAULT);
 	}

 	@Override
 	protected void init(Repository repository, String gitDir) {
 		super.init(repository, gitDir);
 		diffFmt = new DiffFormatter(new BufferedOutputStream(outs));
 	}

 	@Override
 	protected void run() {
 		config = new GpgConfig(db.getConfig());
 		diffFmt.setRepository(db);
 		try {
 			diffFmt.setPathFilter(pathFilter);
 			if (detectRenames != null) {
 				diffFmt.setDetectRenames(detectRenames.booleanValue());
 			}
 			if (renameLimit != null && diffFmt.isDetectRenames()) {
 				RenameDetector rd = diffFmt.getRenameDetector();
 				rd.setRenameLimit(renameLimit.intValue());
 			}

 			if (!noStandardNotes || !additionalNoteRefs.isEmpty()) {
 				createWalk();
 				noteMaps = new LinkedHashMap<>();
 				if (!noStandardNotes) {
 					addNoteMap(Constants.R_NOTES_COMMITS);
 				}
 				if (!additionalNoteRefs.isEmpty()) {
 					for (String notesRef : additionalNoteRefs) {
 						if (!notesRef.startsWith(Constants.R_NOTES)) {
 							notesRef = Constants.R_NOTES + notesRef;
 						}
 						addNoteMap(notesRef);
 					}
 				}
 			}

 			if (decorate) {
 				allRefsByPeeledObjectId = getRepository()
 						.getAllRefsByPeeledObjectId();
 			}
 			super.run();
 		} catch (Exception e) {
 			throw die(e.getMessage(), e);
 		} finally {
 			diffFmt.close();
 		}
 	}

 	private void addNoteMap(String notesRef) throws IOException {
 		Ref notes = db.exactRef(notesRef);
 		if (notes == null)
 			return;
 		RevCommit notesCommit = argWalk.parseCommit(notes.getObjectId());
 		noteMaps.put(notesRef,
 				NoteMap.read(argWalk.getObjectReader(), notesCommit));
 	}

 	@Override
 	protected void show(RevCommit c) throws Exception {
 		outw.print(CLIText.get().commitLabel);
 		outw.print(" "); //$NON-NLS-1$
 		c.getId().copyTo(outbuffer, outw);
 		if (decorate) {
 			Collection<Ref> list = allRefsByPeeledObjectId.get(c);
 			if (list != null) {
 				outw.print(" ("); //$NON-NLS-1$
 				for (Iterator<Ref> i = list.iterator(); i.hasNext(); ) {
 					outw.print(i.next().getName());
 					if (i.hasNext())
 						outw.print(" "); //$NON-NLS-1$
 				}
 				outw.print(")"); //$NON-NLS-1$
 			}
 		}
 		outw.println();

 		if (showSignature) {
 			showSignature(c);
 		}
 		final PersonIdent author = c.getAuthorIdent();
 		outw.println(MessageFormat.format(CLIText.get().authorInfo, author.getName(), author.getEmailAddress()));
 		outw.println(MessageFormat.format(CLIText.get().dateInfo,
 				dateFormatter.formatDate(author)));

 		outw.println();
 		final String[] lines = c.getFullMessage().split("\n"); //$NON-NLS-1$
 		for (String s : lines) {
 			outw.print("    "); //$NON-NLS-1$
 			outw.print(s);
 			outw.println();
 		}
 		c.disposeBody();

 		outw.println();
 		if (showNotes(c))
 			outw.println();

 		if (c.getParentCount() <= 1 && (showNameAndStatusOnly || showPatch
 				|| showNameOnly)) {
 			showDiff(c);
 		}
 		outw.flush();
 	}

 	private void showSignature(RevCommit c) throws IOException {
 		if (c.getRawGpgSignature() == null) {
 			return;
 		}
 		SignatureVerification verification = SignatureVerifiers.verify(db,
 				config, c);
 		if (verification == null) {
 			return;
 		}
 		VerificationUtils.writeVerification(outw, verification,
 				verification.verifierName(), c.getCommitterIdent());
 	}

 	/**
 	 * Show notes for given commit
 	 *
 	 * @param c
 	 *            given commit
 	 * @return <code>true</code> if at least one note was printed,
 	 *         <code>false</code> otherwise
 	 * @throws IOException
 	 *             if an IO error occurred
 	 */
 	private boolean showNotes(RevCommit c) throws IOException {
 		if (noteMaps == null)
 			return false;

 		boolean printEmptyLine = false;
 		boolean atLeastOnePrinted = false;
 		for (Map.Entry<String, NoteMap> e : noteMaps.entrySet()) {
 			String label = null;
 			String notesRef = e.getKey();
 			if (! notesRef.equals(Constants.R_NOTES_COMMITS)) {
 				if (notesRef.startsWith(Constants.R_NOTES))
 					label = notesRef.substring(Constants.R_NOTES.length());
 				else
 					label = notesRef;
 			}
 			boolean printedNote = showNotes(c, e.getValue(), label,
 					printEmptyLine);
 			atLeastOnePrinted |= printedNote;
 			printEmptyLine = printedNote;
 		}
 		return atLeastOnePrinted;
 	}

 	/**
 	 * @param c
 	 *            given commit
 	 * @param map
 	 *            note map
 	 * @param label
 	 *            label
 	 * @param emptyLine
 	 *            whether to start with an empty line
 	 * @return <code>true</code> if note was printed, <code>false</code>
 	 *         otherwise
 	 * @throws IOException
 	 *             if an IO error occurred
 	 */
 	private boolean showNotes(RevCommit c, NoteMap map, String label,
 			boolean emptyLine)
 			throws IOException {
 		ObjectId blobId = map.get(c);
 		if (blobId == null)
 			return false;
 		if (emptyLine)
 			outw.println();
 		outw.print("Notes"); //$NON-NLS-1$
 		if (label != null) {
 			outw.print(" ("); //$NON-NLS-1$
 			outw.print(label);
 			outw.print(")"); //$NON-NLS-1$
 		}
 		outw.println(":"); //$NON-NLS-1$
 		try {
 			RawText rawText = new RawText(argWalk.getObjectReader()
 					.open(blobId).getCachedBytes(Integer.MAX_VALUE));
 			for (int i = 0; i < rawText.size(); i++) {
 				outw.print("    "); //$NON-NLS-1$
 				outw.println(rawText.getString(i));
 			}
 		} catch (LargeObjectException e) {
 			outw.println(MessageFormat.format(
 					CLIText.get().noteObjectTooLargeToPrint, blobId.name()));
 		}
 		return true;
 	}

 	private void showDiff(RevCommit c) throws IOException {
 		final RevTree a = c.getParentCount() > 0 ? c.getParent(0).getTree()
 				: null;
 		final RevTree b = c.getTree();

 		if (showNameAndStatusOnly) {
 			Diff.nameStatus(outw, diffFmt.scan(a, b));
 		} else if (showNameOnly) {
 			Diff.nameOnly(outw, diffFmt.scan(a, b));
 		} else {
 			outw.flush();
 			diffFmt.format(a, b);
 			diffFmt.flush();
 		}
 		outw.println();
 	}
 }
	/*
	* Copyright (C) 2010, Google Inc.
	* Copyright (C) 2006, 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
	* Copyright (C) 2008, 2021, Shawn O. Pearce <spearce@spearce.org> 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
	* https://www.eclipse.org/org/documents/edl-v10.php.
	*
	* SPDX-License-Identifier: BSD-3-Clause
	*/

	package org.eclipse.jgit.pgm;

	import java.io.BufferedOutputStream;
	import java.io.IOException;
	import java.text.MessageFormat;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Iterator;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Set;

	import org.eclipse.jgit.diff.DiffFormatter;
	import org.eclipse.jgit.diff.RawText;
	import org.eclipse.jgit.diff.RawTextComparator;
	import org.eclipse.jgit.diff.RenameDetector;
	import org.eclipse.jgit.errors.LargeObjectException;
	import org.eclipse.jgit.lib.AnyObjectId;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.GpgConfig;
	import org.eclipse.jgit.lib.SignatureVerifier.SignatureVerification;
	import org.eclipse.jgit.lib.ObjectId;
	import org.eclipse.jgit.lib.PersonIdent;
	import org.eclipse.jgit.lib.Ref;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.lib.SignatureVerifiers;
	import org.eclipse.jgit.notes.NoteMap;
	import org.eclipse.jgit.pgm.internal.CLIText;
	import org.eclipse.jgit.pgm.internal.VerificationUtils;
	import org.eclipse.jgit.revwalk.RevCommit;
	import org.eclipse.jgit.revwalk.RevTree;
	import org.eclipse.jgit.util.GitDateFormatter;
	import org.eclipse.jgit.util.GitDateFormatter.Format;
	import org.kohsuke.args4j.Option;

	@Command(common = true, usage = "usage_viewCommitHistory")
	class Log extends RevWalkTextBuiltin {

	private GitDateFormatter dateFormatter = new GitDateFormatter(
	Format.DEFAULT);

	private DiffFormatter diffFmt;

	private Map<AnyObjectId, Set<Ref>> allRefsByPeeledObjectId;

	private Map<String, NoteMap> noteMaps;

	private boolean showNameOnly = false;

	private boolean showNameAndStatusOnly = false;

	@Option(name="--decorate", usage="usage_showRefNamesMatchingCommits")
	private boolean decorate;

	@Option(name = "--no-standard-notes", usage = "usage_noShowStandardNotes")
	private boolean noStandardNotes;

	private List<String> additionalNoteRefs = new ArrayList<>();

	@Option(name = "--show-notes", usage = "usage_showNotes", metaVar = "metaVar_ref")
	void addAdditionalNoteRef(String notesRef) {
	additionalNoteRefs.add(notesRef);
	}

	@Option(name = "--show-signature", usage = "usage_showSignature")
	private boolean showSignature;

	@Option(name = "--date", usage = "usage_date")
	void dateFormat(String date) {
	if (date.toLowerCase(Locale.ROOT).equals(date))
	date = date.toUpperCase(Locale.ROOT);
	dateFormatter = new GitDateFormatter(Format.valueOf(date));
	}

	// BEGIN -- Options shared with Diff
	@Option(name = "-p", usage = "usage_showPatch")
	boolean showPatch;

	@Option(name = "-M", usage = "usage_detectRenames")
	private Boolean detectRenames;

	@Option(name = "--no-renames", usage = "usage_noRenames")
	void noRenames(@SuppressWarnings("unused") boolean on) {
	detectRenames = Boolean.FALSE;
	}

	@Option(name = "-l", usage = "usage_renameLimit")
	private Integer renameLimit;

	@Option(name = "--name-status", usage = "usage_nameStatus")
	void nameAndStatusOnly(boolean on) {
	if (showNameOnly) {
	throw new IllegalArgumentException(
	CLIText.get().cannotUseNameStatusOnlyAndNameOnly);
	}
	showNameAndStatusOnly = on;
	}

	@Option(name = "--name-only", usage = "usage_nameOnly")
	void nameOnly(boolean on) {
	if (showNameAndStatusOnly) {
	throw new IllegalArgumentException(
	CLIText.get().cannotUseNameStatusOnlyAndNameOnly);
	}
	showNameOnly = on;
	}

	@Option(name = "--ignore-space-at-eol")
	void ignoreSpaceAtEol(@SuppressWarnings("unused") boolean on) {
	diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_TRAILING);
	}

	@Option(name = "--ignore-leading-space")
	void ignoreLeadingSpace(@SuppressWarnings("unused") boolean on) {
	diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_LEADING);
	}

	@Option(name = "-b", aliases = { "--ignore-space-change" })
	void ignoreSpaceChange(@SuppressWarnings("unused") boolean on) {
	diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_CHANGE);
	}

	@Option(name = "-w", aliases = { "--ignore-all-space" })
	void ignoreAllSpace(@SuppressWarnings("unused") boolean on) {
	diffFmt.setDiffComparator(RawTextComparator.WS_IGNORE_ALL);
	}

	@Option(name = "-U", aliases = { "--unified" }, metaVar = "metaVar_linesOfContext")
	void unified(int lines) {
	diffFmt.setContext(lines);
	}

	@Option(name = "--abbrev", metaVar = "metaVar_n")
	void abbrev(int lines) {
	diffFmt.setAbbreviationLength(lines);
	}

	@Option(name = "--full-index")
	void abbrev(@SuppressWarnings("unused") boolean on) {
	diffFmt.setAbbreviationLength(Constants.OBJECT_ID_STRING_LENGTH);
	}

	@Option(name = "--src-prefix", usage = "usage_srcPrefix")
	void sourcePrefix(String path) {
	diffFmt.setOldPrefix(path);
	}

	@Option(name = "--dst-prefix", usage = "usage_dstPrefix")
	void dstPrefix(String path) {
	diffFmt.setNewPrefix(path);
	}

	@Option(name = "--no-prefix", usage = "usage_noPrefix")
	void noPrefix(@SuppressWarnings("unused") boolean on) {
	diffFmt.setOldPrefix(""); //$NON-NLS-1$
	diffFmt.setNewPrefix(""); //$NON-NLS-1$
	}

	// END -- Options shared with Diff


	private GpgConfig config;

	Log() {
	dateFormatter = new GitDateFormatter(Format.DEFAULT);
	}

	@Override
	protected void init(Repository repository, String gitDir) {
	super.init(repository, gitDir);
	diffFmt = new DiffFormatter(new BufferedOutputStream(outs));
	}

	@Override
	protected void run() {
	config = new GpgConfig(db.getConfig());
	diffFmt.setRepository(db);
	try {
	diffFmt.setPathFilter(pathFilter);
	if (detectRenames != null) {
	diffFmt.setDetectRenames(detectRenames.booleanValue());
	}
	if (renameLimit != null && diffFmt.isDetectRenames()) {
	RenameDetector rd = diffFmt.getRenameDetector();
	rd.setRenameLimit(renameLimit.intValue());
	}

	if (!noStandardNotes \|\| !additionalNoteRefs.isEmpty()) {
	createWalk();
	noteMaps = new LinkedHashMap<>();
	if (!noStandardNotes) {
	addNoteMap(Constants.R_NOTES_COMMITS);
	}
	if (!additionalNoteRefs.isEmpty()) {
	for (String notesRef : additionalNoteRefs) {
	if (!notesRef.startsWith(Constants.R_NOTES)) {
	notesRef = Constants.R_NOTES + notesRef;
	}
	addNoteMap(notesRef);
	}
	}
	}

	if (decorate) {
	allRefsByPeeledObjectId = getRepository()
	.getAllRefsByPeeledObjectId();
	}
	super.run();
	} catch (Exception e) {
	throw die(e.getMessage(), e);
	} finally {
	diffFmt.close();
	}
	}

	private void addNoteMap(String notesRef) throws IOException {
	Ref notes = db.exactRef(notesRef);
	if (notes == null)
	return;
	RevCommit notesCommit = argWalk.parseCommit(notes.getObjectId());
	noteMaps.put(notesRef,
	NoteMap.read(argWalk.getObjectReader(), notesCommit));
	}

	@Override
	protected void show(RevCommit c) throws Exception {
	outw.print(CLIText.get().commitLabel);
	outw.print(" "); //$NON-NLS-1$
	c.getId().copyTo(outbuffer, outw);
	if (decorate) {
	Collection<Ref> list = allRefsByPeeledObjectId.get(c);
	if (list != null) {
	outw.print(" ("); //$NON-NLS-1$
	for (Iterator<Ref> i = list.iterator(); i.hasNext(); ) {
	outw.print(i.next().getName());
	if (i.hasNext())
	outw.print(" "); //$NON-NLS-1$
	}
	outw.print(")"); //$NON-NLS-1$
	}
	}
	outw.println();

	if (showSignature) {
	showSignature(c);
	}
	final PersonIdent author = c.getAuthorIdent();
	outw.println(MessageFormat.format(CLIText.get().authorInfo, author.getName(), author.getEmailAddress()));
	outw.println(MessageFormat.format(CLIText.get().dateInfo,
	dateFormatter.formatDate(author)));

	outw.println();
	final String[] lines = c.getFullMessage().split("\n"); //$NON-NLS-1$
	for (String s : lines) {
	outw.print(" "); //$NON-NLS-1$
	outw.print(s);
	outw.println();
	}
	c.disposeBody();

	outw.println();
	if (showNotes(c))
	outw.println();

	if (c.getParentCount() <= 1 && (showNameAndStatusOnly \|\| showPatch
	\|\| showNameOnly)) {
	showDiff(c);
	}
	outw.flush();
	}

	private void showSignature(RevCommit c) throws IOException {
	if (c.getRawGpgSignature() == null) {
	return;
	}
	SignatureVerification verification = SignatureVerifiers.verify(db,
	config, c);
	if (verification == null) {
	return;
	}
	VerificationUtils.writeVerification(outw, verification,
	verification.verifierName(), c.getCommitterIdent());
	}

	/**
	* Show notes for given commit
	*
	* @param c
	* given commit
	* @return <code>true</code> if at least one note was printed,
	* <code>false</code> otherwise
	* @throws IOException
	* if an IO error occurred
	*/
	private boolean showNotes(RevCommit c) throws IOException {
	if (noteMaps == null)
	return false;

	boolean printEmptyLine = false;
	boolean atLeastOnePrinted = false;
	for (Map.Entry<String, NoteMap> e : noteMaps.entrySet()) {
	String label = null;
	String notesRef = e.getKey();
	if (! notesRef.equals(Constants.R_NOTES_COMMITS)) {
	if (notesRef.startsWith(Constants.R_NOTES))
	label = notesRef.substring(Constants.R_NOTES.length());
	else
	label = notesRef;
	}
	boolean printedNote = showNotes(c, e.getValue(), label,
	printEmptyLine);
	atLeastOnePrinted \|= printedNote;
	printEmptyLine = printedNote;
	}
	return atLeastOnePrinted;
	}

	/**
	* @param c
	* given commit
	* @param map
	* note map
	* @param label
	* label
	* @param emptyLine
	* whether to start with an empty line
	* @return <code>true</code> if note was printed, <code>false</code>
	* otherwise
	* @throws IOException
	* if an IO error occurred
	*/
	private boolean showNotes(RevCommit c, NoteMap map, String label,
	boolean emptyLine)
	throws IOException {
	ObjectId blobId = map.get(c);
	if (blobId == null)
	return false;
	if (emptyLine)
	outw.println();
	outw.print("Notes"); //$NON-NLS-1$
	if (label != null) {
	outw.print(" ("); //$NON-NLS-1$
	outw.print(label);
	outw.print(")"); //$NON-NLS-1$
	}
	outw.println(":"); //$NON-NLS-1$
	try {
	RawText rawText = new RawText(argWalk.getObjectReader()
	.open(blobId).getCachedBytes(Integer.MAX_VALUE));
	for (int i = 0; i < rawText.size(); i++) {
	outw.print(" "); //$NON-NLS-1$
	outw.println(rawText.getString(i));
	}
	} catch (LargeObjectException e) {
	outw.println(MessageFormat.format(
	CLIText.get().noteObjectTooLargeToPrint, blobId.name()));
	}
	return true;
	}

	private void showDiff(RevCommit c) throws IOException {
	final RevTree a = c.getParentCount() > 0 ? c.getParent(0).getTree()
	: null;
	final RevTree b = c.getTree();

	if (showNameAndStatusOnly) {
	Diff.nameStatus(outw, diffFmt.scan(a, b));
	} else if (showNameOnly) {
	Diff.nameOnly(outw, diffFmt.scan(a, b));
	} else {
	outw.flush();
	diffFmt.format(a, b);
	diffFmt.flush();
	}
	outw.println();
	}
	}