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.transport.nio;
018
019import java.io.IOException;
020import java.io.InputStream;
021import java.nio.BufferUnderflowException;
022import java.nio.ByteBuffer;
023
024/**
025 * An optimized buffered input stream for Tcp
026 * 
027 * 
028 */
029public class NIOInputStream extends InputStream {
030
031    protected int count;
032    protected int position;
033    private final ByteBuffer in;
034
035    public NIOInputStream(ByteBuffer in) {
036        this.in = in;
037    }
038
039    public int read() throws IOException {
040        try {
041            int rc = in.get() & 0xff;
042            return rc;
043        } catch (BufferUnderflowException e) {
044            return -1;
045        }
046    }
047
048    public int read(byte b[], int off, int len) throws IOException {
049        if (in.hasRemaining()) {
050            int rc = Math.min(len, in.remaining());
051            in.get(b, off, rc);
052            return rc;
053        } else {
054            return len == 0 ? 0 : -1;
055        }
056    }
057
058    public long skip(long n) throws IOException {
059        int rc = Math.min((int)n, in.remaining());
060        in.position(in.position() + rc);
061        return rc;
062    }
063
064    public int available() throws IOException {
065        return in.remaining();
066    }
067
068    public boolean markSupported() {
069        return false;
070    }
071
072    public void close() throws IOException {
073    }
074}