| /** |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.activemq.transport.tcp; |
| |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * An optimized buffered input stream for Tcp |
| * |
| * |
| */ |
| public class TcpBufferedInputStream extends FilterInputStream { |
| private static final int DEFAULT_BUFFER_SIZE = 8192; |
| protected byte internalBuffer[]; |
| protected int count; |
| protected int position; |
| |
| public TcpBufferedInputStream(InputStream in) { |
| this(in, DEFAULT_BUFFER_SIZE); |
| } |
| |
| public TcpBufferedInputStream(InputStream in, int size) { |
| super(in); |
| if (size <= 0) { |
| throw new IllegalArgumentException("Buffer size <= 0"); |
| } |
| internalBuffer = new byte[size]; |
| } |
| |
| protected void fill() throws IOException { |
| byte[] buffer = internalBuffer; |
| count = 0; |
| position = 0; |
| int n = in.read(buffer, position, buffer.length - position); |
| if (n > 0) { |
| count = n + position; |
| } |
| } |
| |
| public int read() throws IOException { |
| if (position >= count) { |
| fill(); |
| if (position >= count) { |
| return -1; |
| } |
| } |
| return internalBuffer[position++] & 0xff; |
| } |
| |
| private int readStream(byte[] b, int off, int len) throws IOException { |
| int avail = count - position; |
| if (avail <= 0) { |
| if (len >= internalBuffer.length) { |
| return in.read(b, off, len); |
| } |
| fill(); |
| avail = count - position; |
| if (avail <= 0) { |
| return -1; |
| } |
| } |
| int cnt = (avail < len) ? avail : len; |
| System.arraycopy(internalBuffer, position, b, off, cnt); |
| position += cnt; |
| return cnt; |
| } |
| |
| public int read(byte b[], int off, int len) throws IOException { |
| if ((off | len | (off + len) | (b.length - (off + len))) < 0) { |
| throw new IndexOutOfBoundsException(); |
| } else if (len == 0) { |
| return 0; |
| } |
| int n = 0; |
| for (;;) { |
| int nread = readStream(b, off + n, len - n); |
| if (nread <= 0) { |
| return (n == 0) ? nread : n; |
| } |
| n += nread; |
| if (n >= len) { |
| return n; |
| } |
| // if not closed but no bytes available, return |
| InputStream input = in; |
| if (input != null && input.available() <= 0) { |
| return n; |
| } |
| } |
| } |
| |
| public long skip(long n) throws IOException { |
| if (n <= 0) { |
| return 0; |
| } |
| long avail = count - position; |
| if (avail <= 0) { |
| return in.skip(n); |
| } |
| long skipped = (avail < n) ? avail : n; |
| position += skipped; |
| return skipped; |
| } |
| |
| public int available() throws IOException { |
| return in.available() + (count - position); |
| } |
| |
| public boolean markSupported() { |
| return false; |
| } |
| |
| public void close() throws IOException { |
| if (in != null) { |
| in.close(); |
| } |
| } |
| } |