Java tutorial
/* * Copyright (C) 2008-2009, Google Inc. * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com> * Copyright (C) 2007-2009, Robin Rosenberg <robin.rosenberg@dewire.com> * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org> * 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.lib; import java.text.MessageFormat; import org.eclipse.jgit.errors.InvalidObjectIdException; import org.eclipse.jgit.internal.JGitText; import org.eclipse.jgit.util.NB; import org.eclipse.jgit.util.RawParseUtils; /** * A mutable SHA-1 abstraction. */ public class MutableObjectId extends AnyObjectId { /** * Empty constructor. Initialize object with default (zeros) value. */ public MutableObjectId() { super(); } /** * Copying constructor. * * @param src * original entry, to copy id from */ MutableObjectId(MutableObjectId src) { fromObjectId(src); } /** * Set any byte in the id. * * @param index * index of the byte to set in the raw form of the ObjectId. Must * be in range [0, * {@link org.eclipse.jgit.lib.Constants#OBJECT_ID_LENGTH}). * @param value * the value of the specified byte at {@code index}. Values are * unsigned and thus are in the range [0,255] rather than the * signed byte range of [-128, 127]. * @throws java.lang.ArrayIndexOutOfBoundsException * {@code index} is less than 0, equal to * {@link org.eclipse.jgit.lib.Constants#OBJECT_ID_LENGTH}, or * greater than * {@link org.eclipse.jgit.lib.Constants#OBJECT_ID_LENGTH}. */ public void setByte(int index, int value) { switch (index >> 2) { case 0: w1 = set(w1, index & 3, value); break; case 1: w2 = set(w2, index & 3, value); break; case 2: w3 = set(w3, index & 3, value); break; case 3: w4 = set(w4, index & 3, value); break; case 4: w5 = set(w5, index & 3, value); break; default: throw new ArrayIndexOutOfBoundsException(index); } } private static int set(int w, int index, int value) { value &= 0xff; switch (index) { case 0: return (w & 0x00ffffff) | (value << 24); case 1: return (w & 0xff00ffff) | (value << 16); case 2: return (w & 0xffff00ff) | (value << 8); case 3: return (w & 0xffffff00) | value; default: throw new ArrayIndexOutOfBoundsException(); } } /** * Make this id match {@link org.eclipse.jgit.lib.ObjectId#zeroId()}. */ public void clear() { w1 = 0; w2 = 0; w3 = 0; w4 = 0; w5 = 0; } /** * Copy an ObjectId into this mutable buffer. * * @param src * the source id to copy from. */ public void fromObjectId(AnyObjectId src) { this.w1 = src.w1; this.w2 = src.w2; this.w3 = src.w3; this.w4 = src.w4; this.w5 = src.w5; } /** * Convert an ObjectId from raw binary representation. * * @param bs * the raw byte buffer to read from. At least 20 bytes must be * available within this byte array. */ public void fromRaw(byte[] bs) { fromRaw(bs, 0); } /** * Convert an ObjectId from raw binary representation. * * @param bs * the raw byte buffer to read from. At least 20 bytes after p * must be available within this byte array. * @param p * position to read the first byte of data from. */ public void fromRaw(byte[] bs, int p) { w1 = NB.decodeInt32(bs, p); w2 = NB.decodeInt32(bs, p + 4); w3 = NB.decodeInt32(bs, p + 8); w4 = NB.decodeInt32(bs, p + 12); w5 = NB.decodeInt32(bs, p + 16); } /** * Convert an ObjectId from binary representation expressed in integers. * * @param ints * the raw int buffer to read from. At least 5 integers must be * available within this integers array. */ public void fromRaw(int[] ints) { fromRaw(ints, 0); } /** * Convert an ObjectId from binary representation expressed in integers. * * @param ints * the raw int buffer to read from. At least 5 integers after p * must be available within this integers array. * @param p * position to read the first integer of data from. */ public void fromRaw(int[] ints, int p) { w1 = ints[p]; w2 = ints[p + 1]; w3 = ints[p + 2]; w4 = ints[p + 3]; w5 = ints[p + 4]; } /** * Convert an ObjectId from binary representation expressed in integers. * * @param a * an int. * @param b * an int. * @param c * an int. * @param d * an int. * @param e * an int. * @since 4.7 */ public void set(int a, int b, int c, int d, int e) { w1 = a; w2 = b; w3 = c; w4 = d; w5 = e; } /** * Convert an ObjectId from hex characters (US-ASCII). * * @param buf * the US-ASCII buffer to read from. At least 40 bytes after * offset must be available within this byte array. * @param offset * position to read the first character from. */ public void fromString(byte[] buf, int offset) { fromHexString(buf, offset); } /** * Convert an ObjectId from hex characters. * * @param str * the string to read from. Must be 40 characters long. */ public void fromString(String str) { if (str.length() != Constants.OBJECT_ID_STRING_LENGTH) throw new IllegalArgumentException(MessageFormat.format(JGitText.get().invalidId, str)); fromHexString(Constants.encodeASCII(str), 0); } private void fromHexString(byte[] bs, int p) { try { w1 = RawParseUtils.parseHexInt32(bs, p); w2 = RawParseUtils.parseHexInt32(bs, p + 8); w3 = RawParseUtils.parseHexInt32(bs, p + 16); w4 = RawParseUtils.parseHexInt32(bs, p + 24); w5 = RawParseUtils.parseHexInt32(bs, p + 32); } catch (ArrayIndexOutOfBoundsException e1) { throw new InvalidObjectIdException(bs, p, Constants.OBJECT_ID_STRING_LENGTH); } } /** {@inheritDoc} */ @Override public ObjectId toObjectId() { return new ObjectId(this); } }