| /* |
| * Copyright (C) 2010, Google Inc. 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.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.Command; |
| 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; |
| |
| @Command(usage = "usage_ShowPackDelta") |
| class ShowPackDelta extends TextBuiltin { |
| @Argument(index = 0) |
| private ObjectId objectId; |
| |
| @Override |
| protected void run() throws Exception { |
| ObjectReader reader = db.newObjectReader(); |
| RevObject obj; |
| try (RevWalk rw = new RevWalk(reader)) { |
| obj = rw.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"); //$NON-NLS-1$ //$NON-NLS-2$ |
| } catch (ArrayIndexOutOfBoundsException bad) { |
| throw die("Object " + obj.name() + " is not a delta", bad); //$NON-NLS-1$ //$NON-NLS-2$ |
| } |
| |
| 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++; |
| |
| try (TemporaryBuffer.Heap raw = new TemporaryBuffer.Heap( |
| bufArray.length); |
| InflaterInputStream inf = new InflaterInputStream( |
| new ByteArrayInputStream(bufArray, ptr, |
| bufArray.length))) { |
| raw.copy(inf); |
| return raw.toByteArray(); |
| } |
| } |
| } |