| /* |
| * 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 |
| * 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.internal.storage.pack; |
| |
| final class DeltaWindowEntry { |
| DeltaWindowEntry prev; |
| DeltaWindowEntry next; |
| ObjectToPack object; |
| |
| /** Complete contents of this object. Lazily loaded. */ |
| byte[] buffer; |
| |
| /** Index of this object's content, to encode other deltas. Lazily loaded. */ |
| DeltaIndex index; |
| |
| final void set(ObjectToPack object) { |
| this.object = object; |
| this.index = null; |
| this.buffer = null; |
| } |
| |
| /** @return current delta chain depth of this object. */ |
| final int depth() { |
| return object.getDeltaDepth(); |
| } |
| |
| /** @return type of the object in this window entry. */ |
| final int type() { |
| return object.getType(); |
| } |
| |
| /** @return estimated unpacked size of the object, in bytes . */ |
| final int size() { |
| return object.getWeight(); |
| } |
| |
| /** @return true if there is no object stored in this entry. */ |
| final boolean empty() { |
| return object == null; |
| } |
| |
| final void makeNext(DeltaWindowEntry e) { |
| // Disconnect e from the chain. |
| e.prev.next = e.next; |
| e.next.prev = e.prev; |
| |
| // Insert e after this. |
| e.next = next; |
| e.prev = this; |
| next.prev = e; |
| next = e; |
| } |
| |
| static DeltaWindowEntry createWindow(int cnt) { |
| // C Git increases the window size supplied by the user by 1. |
| // We don't know why it does this, but if the user asks for |
| // window=10, it actually processes with window=11. Because |
| // the window size has the largest direct impact on the final |
| // pack file size, we match this odd behavior here to give us |
| // a better chance of producing a similar sized pack as C Git. |
| // |
| // We would prefer to directly honor the user's request since |
| // PackWriter has a minimum of 2 for the window size, but then |
| // users might complain that JGit is creating a bigger pack file. |
| DeltaWindowEntry res = new DeltaWindowEntry(); |
| DeltaWindowEntry p = res; |
| for (int i = 0; i < cnt; i++) { |
| DeltaWindowEntry e = new DeltaWindowEntry(); |
| e.prev = p; |
| p.next = e; |
| p = e; |
| } |
| p.next = res; |
| res.prev = p; |
| return res; |
| } |
| } |