001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.util;
018
019import java.io.IOException;
020import java.io.InputStream;
021
022/**
023 * Very similar to the java.io.ByteArrayInputStream but this version is not
024 * thread safe.
025 */
026public class ByteArrayInputStream extends InputStream {
027
028    byte buffer[];
029    int limit;
030    int pos;
031    int mark;
032
033    public ByteArrayInputStream(byte data[]) {
034        this(data, 0, data.length);
035    }
036
037    public ByteArrayInputStream(ByteSequence sequence) {
038        this(sequence.getData(), sequence.getOffset(), sequence.getLength());
039    }
040
041    public ByteArrayInputStream(byte data[], int offset, int size) {
042        this.buffer = data;
043        this.mark = offset;
044        this.pos = offset;
045        this.limit = offset + size;
046    }
047
048    public int read() throws IOException {
049        if (pos < limit) {
050            return buffer[pos++] & 0xff;
051        } else {
052            return -1;
053        }
054    }
055
056    public int read(byte[] b) throws IOException {
057        return read(b, 0, b.length);
058    }
059
060    public int read(byte b[], int off, int len) {
061        if (pos < limit) {
062            len = Math.min(len, limit - pos);
063            if (len > 0) {
064                System.arraycopy(buffer, pos, b, off, len);
065                pos += len;
066            }
067            return len;
068        } else {
069            return -1;
070        }
071    }
072
073    public long skip(long len) throws IOException {
074        if (pos < limit) {
075            len = Math.min(len, limit - pos);
076            if (len > 0) {
077                pos += len;
078            }
079            return len;
080        } else {
081            return -1;
082        }
083    }
084
085    public int available() {
086        return limit - pos;
087    }
088
089    public boolean markSupported() {
090        return true;
091    }
092
093    public void mark(int markpos) {
094        mark = pos;
095    }
096
097    public void reset() {
098        pos = mark;
099    }
100}