Mercurial > jhg
diff src/org/tmatesoft/hg/internal/ByteArrayDataAccess.java @ 157:d5268ca7715b
Merged branch wrap-data-access into default for resource-friendly data access. Updated API to promote that friendliness to clients (channels, not byte[]). More exceptions
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Wed, 09 Mar 2011 05:22:17 +0100 |
parents | src/com/tmate/hgkit/fs/ByteArrayDataAccess.java@9429c7bd1920 |
children | b413b16d10a5 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/tmatesoft/hg/internal/ByteArrayDataAccess.java Wed Mar 09 05:22:17 2011 +0100 @@ -0,0 +1,90 @@ +/* + * 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(); + } + System.arraycopy(data, pos, buf, off, len); + pos += len; + } + + @Override + public ByteArrayDataAccess reset() { + pos = 0; + return this; + } + @Override + public long length() { + return length; + } + @Override + public void seek(long offset) { + pos = (int) offset; + } + @Override + public void skip(int bytes) throws IOException { + 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; + } +}