blame: Implement blame on the command line

Command line options match the C implementation of `git blame` as
closely as possible, making for a pretty complete tool.

Change-Id: Ie1bd172ad9de586c3b60f0ee4a77a8f047364882
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit.pgm/META-INF/MANIFEST.MF

@@ -9,6 +9,7 @@ Bundle-RequiredExecutionEnvironment: J2SE-1.5
 Import-Package: org.eclipse.jgit.api;version="[1.1.0,1.2.0)",
  org.eclipse.jgit.api.errors;version="[1.1.0,1.2.0)",
  org.eclipse.jgit.awtui;version="[1.1.0,1.2.0)",
+ org.eclipse.jgit.blame;version="[1.1.0,1.2.0)",
  org.eclipse.jgit.diff;version="[1.1.0,1.2.0)",
  org.eclipse.jgit.dircache;version="[1.1.0,1.2.0)",
  org.eclipse.jgit.errors;version="[1.1.0,1.2.0)",

org.eclipse.jgit.pgm/META-INF/services/org.eclipse.jgit.pgm.TextBuiltin

@@ -1,5 +1,6 @@
 org.eclipse.jgit.pgm.Add
 org.eclipse.jgit.pgm.AmazonS3Client
+org.eclipse.jgit.pgm.Blame
 org.eclipse.jgit.pgm.Branch
 org.eclipse.jgit.pgm.Checkout
 org.eclipse.jgit.pgm.Clone

org.eclipse.jgit.pgm/jgit.sh

@@ -52,6 +52,7 @@ done
 
 use_pager=
 case "$cmd" in
+blame)    use_pager=1 ;;
 diff)     use_pager=1 ;;
 log)      use_pager=1 ;;
 esac

org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/CLIText.properties

@@ -51,6 +51,7 @@ failedToLockTag=Failed to lock tag {0}: {1}
 fatalError=fatal: {0}
 fatalErrorTagExists=fatal: tag '{0}' exists
 fatalThisProgramWillDestroyTheRepository=fatal: This program will destroy the repository\nfatal:\nfatal:\nfatal:    {0}\nfatal:\nfatal: To continue, add {1} to the command line\nfatal:
+fileIsRequired=argument file is required
 forcedUpdate=forced update
 fromURI=From {0}
 initializedEmptyGitRepositoryIn=Initialized empty Git repository in {0}
@@ -65,6 +66,8 @@ metaVar_KEY=KEY
 metaVar_arg=ARG
 metaVar_author=AUTHOR
 metaVar_base=base
+metaVar_blameL=START,END
+metaVar_blameReverse=START..END
 metaVar_bucket=BUCKET
 metaVar_command=command
 metaVar_commandDetail=DETAIL
@@ -93,6 +96,7 @@ metaVar_ref=REF
 metaVar_refs=REFS
 metaVar_refspec=refspec
 metaVar_remoteName=name
+metaVar_revision=REVISION
 metaVar_seconds=SECONDS
 metaVar_service=SERVICE
 metaVar_treeish=tree-ish
@@ -132,6 +136,7 @@ timeInMilliSeconds={0} ms
 tooManyRefsGiven=Too many refs given
 unknownMergeStratey=unknown merge strategy {0} specified
 unsupportedOperation=Unsupported operation: {0}
+usage_Blame=Show what revision and author last modified each line
 usage_CommandLineClientForamazonsS3Service=Command line client for Amazon's S3 service
 usage_CommitAuthor=Override the author name used in the commit. You can use the standard A U Thor <author@example.com> format.
 usage_CommitMessage=Use the given <msg> as the commit message
@@ -152,11 +157,22 @@ usage_ServerSideBackendForJgitPush=Server side backend for 'jgit push'
 usage_ShowDiffs=Show diffs
 usage_StopTrackingAFile=Stop tracking a file
 usage_UpdateRemoteRepositoryFromLocalRefs=Update remote repository from local refs
+usage_abbrevCommits=abbreviate commits to N + 1 digits
 usage_abortConnectionIfNoActivity=abort connection if no activity
 usage_actOnRemoteTrackingBranches=act on remote-tracking branches
 usage_addFileContentsToTheIndex=Add file contents to the index
 usage_alterTheDetailShown=alter the detail shown
 usage_approveDestructionOfRepository=approve destruction of repository
+usage_blameLongRevision=show long revision
+usage_blameRange=annotate only the given range
+usage_blameRawTimestamp=show raw timestamp
+usage_blameReverse=show origin of deletions instead of insertions
+usage_blameShowBlankBoundary=show blank SHA-1 for boundary commits
+usage_blameShowEmail=show author email instead of name
+usage_blameShowRoot=do not treat root commits as boundaries
+usage_blameShowSourceLine=show source line number
+usage_blameShowSourcePath=show source filename
+usage_blameSuppressAuthor=do not show author name and timestamp
 usage_beMoreVerbose=be more verbose
 usage_beVerbose=be verbose
 usage_cached=compare against index
@@ -188,6 +204,7 @@ usage_forceCreateBranchEvenExists=force create branch even exists
 usage_forceReplacingAnExistingTag=force replacing an existing tag
 usage_hostnameOrIpToListenOn=hostname (or ip) to listen on
 usage_indexFileFormatToCreate=index file format to create
+usage_ignoreWhitespace=ignore all whitespace
 usage_inputOutputFile=Input/output file
 usage_listBothRemoteTrackingAndLocalBranches=list both remote-tracking and local branches
 usage_listCreateOrDeleteBranches=List, create, or delete branches

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

@@ -0,0 +1,350 @@
+/*
+ * Copyright (C) 2011, Google Inc.
+ * Copyright (C) 2009, Christian Halstrick <christian.halstrick@sap.com>
+ * Copyright (C) 2009, Johannes E. Schindelin
+ * Copyright (C) 2009, Johannes Schindelin <johannes.schindelin@gmx.de>
+ * 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.pgm;
+
+import static org.eclipse.jgit.lib.Constants.OBJECT_ID_STRING_LENGTH;
+
+import java.io.File;
+import java.io.IOException;
+import java.text.MessageFormat;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
+
+import org.eclipse.jgit.blame.BlameGenerator;
+import org.eclipse.jgit.blame.BlameResult;
+import org.eclipse.jgit.diff.RawText;
+import org.eclipse.jgit.diff.RawTextComparator;
+import org.eclipse.jgit.dircache.DirCache;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectReader;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevFlag;
+import org.kohsuke.args4j.Argument;
+import org.kohsuke.args4j.Option;
+
+@Command(common = false, usage = "usage_Blame")
+class Blame extends TextBuiltin {
+	private RawTextComparator comparator = RawTextComparator.DEFAULT;
+
+	@Option(name = "-w", usage = "usage_ignoreWhitespace")
+	void ignoreAllSpace(@SuppressWarnings("unused") boolean on) {
+		comparator = RawTextComparator.WS_IGNORE_ALL;
+	}
+
+	@Option(name = "--abbrev", metaVar = "metaVar_n", usage = "usage_abbrevCommits")
+	private int abbrev;
+
+	@Option(name = "-l", usage = "usage_blameLongRevision")
+	private boolean showLongRevision;
+
+	@Option(name = "-t", usage = "usage_blameRawTimestamp")
+	private boolean showRawTimestamp;
+
+	@Option(name = "-b", usage = "usage_blameShowBlankBoundary")
+	private boolean showBlankBoundary;
+
+	@Option(name = "-s", usage = "usage_blameSuppressAuthor")
+	private boolean noAuthor;
+
+	@Option(name = "--show-email", aliases = { "-e" }, usage = "usage_blameShowEmail")
+	private boolean showAuthorEmail;
+
+	@Option(name = "--show-name", aliases = { "-f" }, usage = "usage_blameShowSourcePath")
+	private boolean showSourcePath;
+
+	@Option(name = "--show-number", aliases = { "-n" }, usage = "usage_blameShowSourceLine")
+	private boolean showSourceLine;
+
+	@Option(name = "--root", usage = "usage_blameShowRoot")
+	private boolean root;
+
+	@Option(name = "-L", metaVar = "metaVar_blameL", usage = "usage_blameRange")
+	private String rangeString;
+
+	@Option(name = "--reverse", metaVar = "metaVar_blameReverse", usage = "usage_blameReverse")
+	private List<RevCommit> reverseRange = new ArrayList<RevCommit>(2);
+
+	@Argument(index = 0, required = false, metaVar = "metaVar_revision")
+	private String revision;
+
+	@Argument(index = 1, required = false, metaVar = "metaVar_file")
+	private String file;
+
+	private ObjectReader reader;
+
+	private final Map<RevCommit, String> abbreviatedCommits = new HashMap<RevCommit, String>();
+
+	private SimpleDateFormat dateFmt;
+
+	private int begin;
+
+	private int end;
+
+	private BlameResult blame;
+
+	@Override
+	protected void run() throws Exception {
+		if (file == null) {
+			if (revision == null)
+				throw die(CLIText.get().fileIsRequired);
+			file = revision;
+			revision = null;
+		}
+
+		if (abbrev == 0)
+			abbrev = db.getConfig().getInt("core", "abbrev", 7);
+		if (!showBlankBoundary)
+			root = db.getConfig().getBoolean("blame", "blankboundary", false);
+		if (!root)
+			root = db.getConfig().getBoolean("blame", "showroot", false);
+
+		if (showRawTimestamp)
+			dateFmt = new SimpleDateFormat("ZZZZ");
+		else
+			dateFmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss ZZZZ");
+
+		BlameGenerator generator = new BlameGenerator(db, file);
+		reader = db.newObjectReader();
+		try {
+			generator.setTextComparator(comparator);
+
+			if (!reverseRange.isEmpty()) {
+				RevCommit rangeStart = null;
+				List<RevCommit> rangeEnd = new ArrayList<RevCommit>(2);
+				for (RevCommit c : reverseRange) {
+					if (c.has(RevFlag.UNINTERESTING))
+						rangeStart = c;
+					else
+						rangeEnd.add(c);
+				}
+				generator.reverse(rangeStart, rangeEnd);
+			} else if (revision != null) {
+				generator.push(null, db.resolve(revision + "^{commit}"));
+			} else {
+				generator.push(null, db.resolve(Constants.HEAD));
+				if (!db.isBare()) {
+					DirCache dc = db.readDirCache();
+					int entry = dc.findEntry(file);
+					if (0 <= entry)
+						generator.push(null, dc.getEntry(entry).getObjectId());
+
+					File inTree = new File(db.getWorkTree(), file);
+					if (inTree.isFile())
+						generator.push(null, new RawText(inTree));
+				}
+			}
+
+			blame = BlameResult.create(generator);
+			begin = 0;
+			end = blame.getResultContents().size();
+			if (rangeString != null)
+				parseLineRangeOption();
+			blame.computeRange(begin, end);
+
+			int authorWidth = 8;
+			int dateWidth = 8;
+			int pathWidth = 1;
+			int maxSourceLine = 1;
+			for (int line = begin; line < end; line++) {
+				authorWidth = Math.max(authorWidth, author(line).length());
+				dateWidth = Math.max(dateWidth, date(line).length());
+				pathWidth = Math.max(pathWidth, path(line).length());
+				maxSourceLine = Math.max(maxSourceLine, blame.getSourceLine(line));
+			}
+
+			String pathFmt = MessageFormat.format(" %{0}s", pathWidth);
+			String numFmt = MessageFormat.format(" %{0}d",
+					1 + (int) Math.log10(maxSourceLine + 1));
+			String lineFmt = MessageFormat.format(" %{0}d) ",
+					1 + (int) Math.log10(end + 1));
+			String authorFmt = MessageFormat.format(" (%-{0}s %{1}s",
+					authorWidth, dateWidth);
+
+			for (int line = begin; line < end; line++) {
+				out.print(abbreviate(blame.getSourceCommit(line)));
+				if (showSourcePath)
+					out.format(pathFmt, path(line));
+				if (showSourceLine)
+					out.format(numFmt, blame.getSourceLine(line) + 1);
+				if (!noAuthor)
+					out.format(authorFmt, author(line), date(line));
+				out.format(lineFmt, line + 1);
+				out.flush();
+				blame.getResultContents().writeLine(System.out, line);
+				out.print('\n');
+			}
+		} finally {
+			generator.release();
+			reader.release();
+		}
+	}
+
+	private void parseLineRangeOption() {
+		String beginStr, endStr;
+		if (rangeString.startsWith("/")) {
+			int c = rangeString.indexOf("/,", 1);
+			if (c < 0) {
+				beginStr = rangeString;
+				endStr = String.valueOf(end);
+			} else {
+				beginStr = rangeString.substring(0, c);
+				endStr = rangeString.substring(c + 2);
+			}
+
+		} else {
+			int c = rangeString.indexOf(',');
+			if (c < 0) {
+				beginStr = rangeString;
+				endStr = String.valueOf(end);
+			} else if (c == 0) {
+				beginStr = "0";
+				endStr = rangeString.substring(1);
+			} else {
+				beginStr = rangeString.substring(0, c);
+				endStr = rangeString.substring(c + 1);
+			}
+		}
+
+		if (beginStr.equals(""))
+			begin = 0;
+		else if (beginStr.startsWith("/"))
+			begin = findLine(0, beginStr);
+		else
+			begin = Math.max(0, Integer.parseInt(beginStr) - 1);
+
+		if (endStr.equals(""))
+			end = blame.getResultContents().size();
+		else if (endStr.startsWith("/"))
+			end = findLine(begin, endStr);
+		else if (endStr.startsWith("-"))
+			end = begin + Integer.parseInt(endStr);
+		else if (endStr.startsWith("+"))
+			end = begin + Integer.parseInt(endStr.substring(1));
+		else
+			end = Math.max(0, Integer.parseInt(endStr) - 1);
+	}
+
+	private int findLine(int b, String regex) {
+		String re = regex.substring(1, regex.length() - 1);
+		if (!re.startsWith("^"))
+			re = ".*" + re;
+		if (!re.endsWith("$"))
+			re = re + ".*";
+		Pattern p = Pattern.compile(re);
+		RawText text = blame.getResultContents();
+		for (int line = b; line < text.size(); line++) {
+			if (p.matcher(text.getString(line)).matches())
+				return line;
+		}
+		return b;
+	}
+
+	private String path(int line) {
+		String p = blame.getSourcePath(line);
+		return p != null ? p : "";
+	}
+
+	private String author(int line) {
+		PersonIdent author = blame.getSourceAuthor(line);
+		if (author == null)
+			return "";
+		String name = showAuthorEmail ? author.getEmailAddress() : author
+				.getName();
+		return name != null ? name : "";
+	}
+
+	private String date(int line) {
+		if (blame.getSourceCommit(line) == null)
+			return "";
+
+		PersonIdent author = blame.getSourceAuthor(line);
+		if (author == null)
+			return "";
+
+		dateFmt.setTimeZone(author.getTimeZone());
+		if (!showRawTimestamp)
+			return dateFmt.format(author.getWhen());
+		return String.format("%d %s", author.getWhen().getTime() / 1000L,
+				dateFmt.format(author.getWhen()));
+	}
+
+	private String abbreviate(RevCommit commit) throws IOException {
+		String r = abbreviatedCommits.get(commit);
+		if (r != null)
+			return r;
+
+		if (showBlankBoundary && commit.getParentCount() == 0)
+			commit = null;
+
+		if (commit == null) {
+			int len = showLongRevision ? OBJECT_ID_STRING_LENGTH : (abbrev + 1);
+			StringBuilder b = new StringBuilder(len);
+			for (int i = 0; i < len; i++)
+				b.append(' ');
+			r = b.toString();
+
+		} else if (!root && commit.getParentCount() == 0) {
+			if (showLongRevision)
+				r = "^" + commit.name().substring(0, OBJECT_ID_STRING_LENGTH - 1);
+			else
+				r = "^" + reader.abbreviate(commit, abbrev).name();
+		} else {
+			if (showLongRevision)
+				r = commit.name();
+			else
+				r = reader.abbreviate(commit, abbrev + 1).name();
+		}
+
+		abbreviatedCommits.put(commit, r);
+		return r;
+	}
+}

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

@@ -104,6 +104,7 @@ public class CLIText extends TranslationBundle {
 	/***/ public String fatalError;
 	/***/ public String fatalErrorTagExists;
 	/***/ public String fatalThisProgramWillDestroyTheRepository;
+	/***/ public String fileIsRequired;
 	/***/ public String forcedUpdate;
 	/***/ public String fromURI;
 	/***/ public String initializedEmptyGitRepositoryIn;