| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 2000 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Xerces" and "Apache Software Foundation" must |
| * not be used to endorse or promote products derived from this |
| * software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 1999, International |
| * Business Machines, Inc., http://www.apache.org. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| |
| package socket.io; |
| |
| import java.io.DataInputStream; |
| import java.io.FilterInputStream; |
| import java.io.InputStream; |
| import java.io.IOException; |
| |
| /** |
| * This input stream works in conjunction with the WrappedOutputStream |
| * to introduce a protocol for reading arbitrary length data in a |
| * uniform way. |
| * <p> |
| * <strong>Note:</strong> See the javadoc for WrappedOutputStream for |
| * more information. |
| * |
| * @see WrappedOutputStream |
| * |
| * @author Andy Clark, IBM |
| * |
| * @version $Id$ |
| */ |
| public class WrappedInputStream |
| extends FilterInputStream { |
| |
| // |
| // Data |
| // |
| |
| /** Bytes left on input stream for current packet. */ |
| protected int fPacketCount; |
| |
| /** |
| * Data input stream. This stream is used to input the block sizes |
| * from the data stream that are written by the WrappedOutputStream. |
| * <p> |
| * <strong>Note:</strong> The data input stream is only used for |
| * reading the byte count for performance reasons. We avoid the |
| * method indirection for reading the byte data. |
| */ |
| protected DataInputStream fDataInputStream; |
| |
| /** To mark that the stream is "closed". */ |
| protected boolean fClosed; |
| |
| // |
| // Constructors |
| // |
| |
| /** Constructs a wrapper for the given an input stream. */ |
| public WrappedInputStream(InputStream stream) { |
| super(stream); |
| fDataInputStream = new DataInputStream(stream); |
| } // <init>(InputStream) |
| |
| // |
| // InputStream methods |
| // |
| |
| /** Reads a single byte. */ |
| public int read() throws IOException { |
| |
| // ignore, if already closed |
| if (fClosed) { |
| return -1; |
| } |
| |
| // read packet header |
| if (fPacketCount == 0) { |
| fPacketCount = fDataInputStream.readShort() & 0x0000FFFF; |
| if (fPacketCount == 0) { |
| fClosed = true; |
| return -1; |
| } |
| } |
| |
| // read a byte from the packet |
| fPacketCount--; |
| return super.in.read(); |
| |
| } // read():int |
| |
| /** |
| * Reads a block of bytes and returns the total number of bytes read. |
| */ |
| public int read(byte[] b, int offset, int length) throws IOException { |
| |
| // ignore, if already closed |
| if (fClosed) { |
| return -1; |
| } |
| |
| // read packet header |
| if (fPacketCount == 0) { |
| fPacketCount = fDataInputStream.readShort() & 0x0000FFFF; |
| if (fPacketCount == 0) { |
| fClosed = true; |
| return -1; |
| } |
| } |
| |
| // read bytes from packet |
| if (length > fPacketCount) { |
| length = fPacketCount; |
| } |
| int count = super.in.read(b, offset, length); |
| if (count == -1) { |
| // NOTE: This condition should not happen. The end of |
| // the stream should always be designated by a |
| // byte count header of 0. -Ac |
| fClosed = true; |
| return -1; |
| } |
| fPacketCount -= count; |
| |
| // return total bytes read |
| return count; |
| |
| } // read(byte[],int,int):int |
| |
| /** Skips the specified number of bytes from the input stream. */ |
| public long skip(long n) throws IOException { |
| if (!fClosed) { |
| // NOTE: This should be rewritten to be more efficient. -Ac |
| for (long i = 0; i < n; i++) { |
| int b = read(); |
| if (b == -1) { |
| return i + 1; |
| } |
| } |
| return n; |
| } |
| return 0; |
| } // skip(long):long |
| |
| /** |
| * Closes the input stream. This method will search for the end of |
| * the wrapped input, positioning the stream at after the end packet. |
| * <p> |
| * <strong>Note:</strong> This method does not close the underlying |
| * input stream. |
| */ |
| public void close() throws IOException { |
| if (!fClosed) { |
| fClosed = true; |
| do { |
| super.in.skip(fPacketCount); |
| fPacketCount = fDataInputStream.readShort() & 0x0000FFFF; |
| } while (fPacketCount > 0); |
| } |
| } // close() |
| |
| } // class WrappedInputStream |
