/*
* Copyright (C) 2010, Google Inc.
* 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
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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package org.eclipse.jgit.pgm.debug;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Collections;
import java.util.zip.InflaterInputStream;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.errors.StoredObjectRepresentationNotAvailableException;
import org.eclipse.jgit.internal.storage.pack.BinaryDelta;
import org.eclipse.jgit.internal.storage.pack.ObjectReuseAsIs;
import org.eclipse.jgit.internal.storage.pack.ObjectToPack;
import org.eclipse.jgit.internal.storage.pack.PackOutputStream;
import org.eclipse.jgit.internal.storage.pack.PackWriter;
import org.eclipse.jgit.internal.storage.pack.StoredObjectRepresentation;
import org.eclipse.jgit.lib.NullProgressMonitor;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.pgm.TextBuiltin;
import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.util.TemporaryBuffer;
import org.kohsuke.args4j.Argument;
class ShowPackDelta extends TextBuiltin {
@Argument(index = 0)
private ObjectId objectId;
@Override
protected void run() throws Exception {
ObjectReader reader = db.newObjectReader();
RevObject obj = new RevWalk(reader).parseAny(objectId);
byte[] delta = getDelta(reader, obj);
// We're crossing our fingers that this will be a delta. Double
// check the size field in the header, it should match.
//
long size = reader.getObjectSize(obj, obj.getType());
try {
if (BinaryDelta.getResultSize(delta) != size)
throw die("Object " + obj.name() + " is not a delta");
} catch (ArrayIndexOutOfBoundsException bad) {
throw die("Object " + obj.name() + " is not a delta");
}
outw.println(BinaryDelta.format(delta));
}
private static byte[] getDelta(ObjectReader reader, RevObject obj)
throws IOException, MissingObjectException,
StoredObjectRepresentationNotAvailableException {
ObjectReuseAsIs asis = (ObjectReuseAsIs) reader;
ObjectToPack target = asis.newObjectToPack(obj, obj.getType());
PackWriter pw = new PackWriter(reader) {
@Override
public void select(ObjectToPack otp, StoredObjectRepresentation next) {
otp.select(next);
}
};
ByteArrayOutputStream buf = new ByteArrayOutputStream();
asis.selectObjectRepresentation(pw, NullProgressMonitor.INSTANCE,
Collections.singleton(target));
asis.copyObjectAsIs(new PackOutputStream(NullProgressMonitor.INSTANCE,
buf, pw), target, true);
// At this point the object header has no delta information,
// because it was output as though it were a whole object.
// Skip over the header and inflate.
//
byte[] bufArray = buf.toByteArray();
int ptr = 0;
while ((bufArray[ptr] & 0x80) != 0)
ptr++;
ptr++;
@SuppressWarnings("resource" /* java 7 */)
TemporaryBuffer.Heap raw = new TemporaryBuffer.Heap(bufArray.length);
InflaterInputStream inf = new InflaterInputStream(
new ByteArrayInputStream(bufArray, ptr, bufArray.length));
raw.copy(inf);
inf.close();
return raw.toByteArray();
}
}