Mercurial > hg4j
view src/org/tmatesoft/hg/internal/ByteArrayDataAccess.java @ 701:02766745dbe6
Added tag v1.2m2 for changeset 6e7786086f77
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Thu, 08 Aug 2013 21:05:21 +0200 |
parents | 545b1d4cc11d |
children |
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/* * Copyright (c) 2011 TMate Software Ltd * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * For information on how to redistribute this software under * the terms of a license other than GNU General Public License * contact TMate Software at support@hg4j.com */ package org.tmatesoft.hg.internal; import java.io.IOException; /** * * @author Artem Tikhomirov * @author TMate Software Ltd. */ public class ByteArrayDataAccess extends DataAccess { private final byte[] data; private final int offset; private final int length; private int pos; public ByteArrayDataAccess(byte[] data) { this(data, 0, data.length); } public ByteArrayDataAccess(byte[] data, int offset, int length) { this.data = data; this.offset = offset; this.length = length; pos = 0; } @Override public byte readByte() throws IOException { if (pos >= length) { throw new IOException(); } return data[offset + pos++]; } @Override public void readBytes(byte[] buf, int off, int len) throws IOException { if (len > (this.length - pos)) { throw new IOException(String.format("Requested %d bytes at position %d of %d total", len, pos, length)); } System.arraycopy(data, offset+pos, buf, off, len); pos += len; } @Override public int readInt() throws IOException { // overridden not to create an intermediate array if (length - pos < 4) { throw new IOException(); } int x = offset + pos; int rv = data[x++] << 24 | (data[x++] & 0xFF) << 16 | (data[x++] & 0xFF) << 8 | (data[x] & 0xFF); pos += 4; return rv; } @Override public long readLong() throws IOException { // overridden not to create an intermediate array if (length - pos < 8) { throw new IOException(); } int x = offset + pos; int i1 = data[x++] << 24 | (data[x++] & 0xFF) << 16 | (data[x++] & 0xFF) << 8 | (data[x++] & 0xFF); int i2 = data[x++] << 24 | (data[x++] & 0xFF) << 16 | (data[x++] & 0xFF) << 8 | (data[x] & 0xFF); pos += 8; return ((long) i1) << 32 | ((long) i2 & 0x0FFFFFFFFl); } @Override public ByteArrayDataAccess reset() { pos = 0; return this; } @Override public int length() { return length; } @Override public void seek(int offset) { pos = offset; } @Override public void skip(int bytes) { seek(pos + bytes); } @Override public boolean isEmpty() { return pos >= length; } // // when byte[] needed from DA, we may save few cycles and some memory giving this (otherwise unsafe) access to underlying data @Override public byte[] byteArray() { return data; } }