Merge branch 'cq-diff'

Per CQ 3559 "JGit - Eugene Myers O(ND) difference algorithm" we
have approval to check this into our master branch.

* cq-diff:
  Add file content merge algorithm
  Add performance tests for MyersDiff
  Add javadoc comments, remove unused code, shift comments to correct place
  Fixed MyersDiff to be able to handle more than 100k
  Fix some warnings regarding unnecessary imports and accessing static methods
  Add the "jgit diff" command
  Prepare RawText for diff-index and diff-files
  Add a test class for Myers' diff algorithm
  Add Myers' algorithm to generate diff scripts
  Add set to IntList

Conflicts:
	org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java

Change-Id: Ia8e98d81ba1ab52f84d0258a40e6ef5eece9a5b1
CC: Christian Halstrick <christian.halstrick@sap.com>

1 files changed, 131 insertions, 0 deletions

diff --git a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Diff.java b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Diff.java
new file mode 100644
index 0000000000..24bcdcc612
--- /dev/null
+++ b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Diff.java
@@ -0,0 +1,131 @@
+/*
+ * 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 java.io.IOException;
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.kohsuke.args4j.Argument;
+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.FileMode;
+import org.eclipse.jgit.lib.ObjectId;
+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));
+
+		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(ObjectId.zeroId())) {
+			out.println("new file mode " + mode2);
+			isNew=true;
+		} else if (id2.equals(ObjectId.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(ObjectId.zeroId()))
+			return new RawText(new byte[] { });
+		return new RawText(db.openBlob(id).getCachedBytes());
+	}
+}
+