Add the "jgit diff" command

This commit contains fixes provided by Christian Halstrick.

Bug: 291083
Eclipse-CQ: 3559
Change-Id: If8d187e70a51f31040f99098489e513791dc6415
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

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

@@ -2,6 +2,7 @@ org.eclipse.jgit.pgm.AmazonS3Client
 org.eclipse.jgit.pgm.Branch
 org.eclipse.jgit.pgm.Clone
 org.eclipse.jgit.pgm.Daemon
+org.eclipse.jgit.pgm.Diff
 org.eclipse.jgit.pgm.DiffTree
 org.eclipse.jgit.pgm.Fetch
 org.eclipse.jgit.pgm.Glog

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

@@ -0,0 +1,140 @@
+/*
+ * 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 java.io.IOException;
+import java.io.PrintStream;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.kohsuke.args4j.Argument;
+import org.kohsuke.args4j.ExampleMode;
+import org.kohsuke.args4j.Option;
+
+import org.eclipse.jgit.diff.DiffFormatter;
+import org.eclipse.jgit.diff.MyersDiff;
+import org.eclipse.jgit.diff.RawText;
+
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.FileMode;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+
+import org.eclipse.jgit.pgm.opt.CmdLineParser;
+import org.eclipse.jgit.pgm.opt.PathTreeFilterHandler;
+
+import org.eclipse.jgit.treewalk.AbstractTreeIterator;
+import org.eclipse.jgit.treewalk.TreeWalk;
+
+import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
+import org.eclipse.jgit.treewalk.filter.TreeFilter;
+
+@Command(common = true, usage = "Show diffs")
+class Diff extends TextBuiltin {
+	@Argument(index = 0, metaVar = "tree-ish", required = true)
+	void tree_0(final AbstractTreeIterator c) {
+		trees.add(c);
+	}
+
+	@Argument(index = 1, metaVar = "tree-ish", required = true)
+	private final List<AbstractTreeIterator> trees = new ArrayList<AbstractTreeIterator>();
+
+	@Option(name = "--", metaVar = "path", multiValued = true, handler = PathTreeFilterHandler.class)
+	private TreeFilter pathFilter = TreeFilter.ALL;
+
+	private DiffFormatter fmt = new DiffFormatter();
+
+	@Override
+	protected void run() throws Exception {
+		final TreeWalk walk = new TreeWalk(db);
+		walk.reset();
+		walk.setRecursive(true);
+		for (final AbstractTreeIterator i : trees)
+			walk.addTree(i);
+		walk.setFilter(AndTreeFilter.create(TreeFilter.ANY_DIFF, pathFilter));
+
+		final int nTree = walk.getTreeCount();
+		while (walk.next())
+			outputDiff(System.out, walk.getPathString(),
+				walk.getObjectId(0), walk.getFileMode(0),
+				walk.getObjectId(1), walk.getFileMode(1));
+	}
+
+	protected void outputDiff(PrintStream out, String path,
+			ObjectId id1, FileMode mode1, ObjectId id2, FileMode mode2) throws IOException {
+		String name1 = "a/" + path;
+		String name2 =  "b/" + path;
+		out.println("diff --git " + name1 + " " + name2);
+		boolean isNew=false;
+		boolean isDelete=false;
+		if (id1.equals(id1.zeroId())) {
+			out.println("new file mode " + mode2);
+			isNew=true;
+		} else if (id2.equals(id2.zeroId())) {
+			out.println("deleted file mode " + mode1);
+			isDelete=true;
+		} else if (!mode1.equals(mode2)) {
+			out.println("old mode " + mode1);
+			out.println("new mode " + mode2);
+		}
+		out.println("index " + id1.abbreviate(db, 7).name()
+			+ ".." + id2.abbreviate(db, 7).name()
+			+ (mode1.equals(mode2) ? " " + mode1 : ""));
+		out.println("--- " + (isNew ?  "/dev/null" : name1));
+		out.println("+++ " + (isDelete ?  "/dev/null" : name2));
+		RawText a = getRawText(id1);
+		RawText b = getRawText(id2);
+		MyersDiff diff = new MyersDiff(a, b);
+		fmt.formatEdits(out, a, b, diff.getEdits());
+	}
+
+	private RawText getRawText(ObjectId id) throws IOException {
+		if (id.equals(id.zeroId()))
+			return new RawText(new byte[] { });
+		return new RawText(db.openBlob(id).getCachedBytes());
+	}
+}
+

org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffFormatter.java

@@ -114,7 +114,7 @@ public class DiffFormatter {
 		formatEdits(out, a, b, head.toEditList());
 	}
 
-	private void formatEdits(final OutputStream out, final RawText a,
+	public void formatEdits(final OutputStream out, final RawText a,
 			final RawText b, final EditList edits) throws IOException {
 		for (int curIdx = 0; curIdx < edits.size();) {
 			Edit curEdit = edits.get(curIdx);