michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.impl.io;
michael@0: 
michael@0: import java.io.IOException;
michael@0: import java.io.InputStream;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.Header;
michael@0: import ch.boye.httpclientandroidlib.HttpException;
michael@0: import ch.boye.httpclientandroidlib.MalformedChunkCodingException;
michael@0: import ch.boye.httpclientandroidlib.TruncatedChunkException;
michael@0: import ch.boye.httpclientandroidlib.io.BufferInfo;
michael@0: import ch.boye.httpclientandroidlib.io.SessionInputBuffer;
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: import ch.boye.httpclientandroidlib.util.ExceptionUtils;
michael@0: 
michael@0: /**
michael@0:  * Implements chunked transfer coding. The content is received in small chunks.
michael@0:  * Entities transferred using this input stream can be of unlimited length.
michael@0:  * After the stream is read to the end, it provides access to the trailers,
michael@0:  * if any.
michael@0:  * <p>
michael@0:  * Note that this class NEVER closes the underlying stream, even when close
michael@0:  * gets called.  Instead, it will read until the "end" of its chunking on
michael@0:  * close, which allows for the seamless execution of subsequent HTTP 1.1
michael@0:  * requests, while not requiring the client to remember to read the entire
michael@0:  * contents of the response.
michael@0:  *
michael@0:  *
michael@0:  * @since 4.0
michael@0:  *
michael@0:  */
michael@0: public class ChunkedInputStream extends InputStream {
michael@0: 
michael@0:     private static final int CHUNK_LEN               = 1;
michael@0:     private static final int CHUNK_DATA              = 2;
michael@0:     private static final int CHUNK_CRLF              = 3;
michael@0: 
michael@0:     private static final int BUFFER_SIZE = 2048;
michael@0: 
michael@0:     /** The session input buffer */
michael@0:     private final SessionInputBuffer in;
michael@0: 
michael@0:     private final CharArrayBuffer buffer;
michael@0: 
michael@0:     private int state;
michael@0: 
michael@0:     /** The chunk size */
michael@0:     private int chunkSize;
michael@0: 
michael@0:     /** The current position within the current chunk */
michael@0:     private int pos;
michael@0: 
michael@0:     /** True if we've reached the end of stream */
michael@0:     private boolean eof = false;
michael@0: 
michael@0:     /** True if this stream is closed */
michael@0:     private boolean closed = false;
michael@0: 
michael@0:     private Header[] footers = new Header[] {};
michael@0: 
michael@0:     /**
michael@0:      * Wraps session input stream and reads chunk coded input.
michael@0:      *
michael@0:      * @param in The session input buffer
michael@0:      */
michael@0:     public ChunkedInputStream(final SessionInputBuffer in) {
michael@0:         super();
michael@0:         if (in == null) {
michael@0:             throw new IllegalArgumentException("Session input buffer may not be null");
michael@0:         }
michael@0:         this.in = in;
michael@0:         this.pos = 0;
michael@0:         this.buffer = new CharArrayBuffer(16);
michael@0:         this.state = CHUNK_LEN;
michael@0:     }
michael@0: 
michael@0:     public int available() throws IOException {
michael@0:         if (this.in instanceof BufferInfo) {
michael@0:             int len = ((BufferInfo) this.in).length();
michael@0:             return Math.min(len, this.chunkSize - this.pos);
michael@0:         } else {
michael@0:             return 0;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * <p> Returns all the data in a chunked stream in coalesced form. A chunk
michael@0:      * is followed by a CRLF. The method returns -1 as soon as a chunksize of 0
michael@0:      * is detected.</p>
michael@0:      *
michael@0:      * <p> Trailer headers are read automatically at the end of the stream and
michael@0:      * can be obtained with the getResponseFooters() method.</p>
michael@0:      *
michael@0:      * @return -1 of the end of the stream has been reached or the next data
michael@0:      * byte
michael@0:      * @throws IOException in case of an I/O error
michael@0:      */
michael@0:     public int read() throws IOException {
michael@0:         if (this.closed) {
michael@0:             throw new IOException("Attempted read from closed stream.");
michael@0:         }
michael@0:         if (this.eof) {
michael@0:             return -1;
michael@0:         }
michael@0:         if (state != CHUNK_DATA) {
michael@0:             nextChunk();
michael@0:             if (this.eof) {
michael@0:                 return -1;
michael@0:             }
michael@0:         }
michael@0:         int b = in.read();
michael@0:         if (b != -1) {
michael@0:             pos++;
michael@0:             if (pos >= chunkSize) {
michael@0:                 state = CHUNK_CRLF;
michael@0:             }
michael@0:         }
michael@0:         return b;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Read some bytes from the stream.
michael@0:      * @param b The byte array that will hold the contents from the stream.
michael@0:      * @param off The offset into the byte array at which bytes will start to be
michael@0:      * placed.
michael@0:      * @param len the maximum number of bytes that can be returned.
michael@0:      * @return The number of bytes returned or -1 if the end of stream has been
michael@0:      * reached.
michael@0:      * @throws IOException in case of an I/O error
michael@0:      */
michael@0:     public int read (byte[] b, int off, int len) throws IOException {
michael@0: 
michael@0:         if (closed) {
michael@0:             throw new IOException("Attempted read from closed stream.");
michael@0:         }
michael@0: 
michael@0:         if (eof) {
michael@0:             return -1;
michael@0:         }
michael@0:         if (state != CHUNK_DATA) {
michael@0:             nextChunk();
michael@0:             if (eof) {
michael@0:                 return -1;
michael@0:             }
michael@0:         }
michael@0:         len = Math.min(len, chunkSize - pos);
michael@0:         int bytesRead = in.read(b, off, len);
michael@0:         if (bytesRead != -1) {
michael@0:             pos += bytesRead;
michael@0:             if (pos >= chunkSize) {
michael@0:                 state = CHUNK_CRLF;
michael@0:             }
michael@0:             return bytesRead;
michael@0:         } else {
michael@0:             eof = true;
michael@0:             throw new TruncatedChunkException("Truncated chunk "
michael@0:                     + "( expected size: " + chunkSize
michael@0:                     + "; actual size: " + pos + ")");
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Read some bytes from the stream.
michael@0:      * @param b The byte array that will hold the contents from the stream.
michael@0:      * @return The number of bytes returned or -1 if the end of stream has been
michael@0:      * reached.
michael@0:      * @throws IOException in case of an I/O error
michael@0:      */
michael@0:     public int read (byte[] b) throws IOException {
michael@0:         return read(b, 0, b.length);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Read the next chunk.
michael@0:      * @throws IOException in case of an I/O error
michael@0:      */
michael@0:     private void nextChunk() throws IOException {
michael@0:         chunkSize = getChunkSize();
michael@0:         if (chunkSize < 0) {
michael@0:             throw new MalformedChunkCodingException("Negative chunk size");
michael@0:         }
michael@0:         state = CHUNK_DATA;
michael@0:         pos = 0;
michael@0:         if (chunkSize == 0) {
michael@0:             eof = true;
michael@0:             parseTrailerHeaders();
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Expects the stream to start with a chunksize in hex with optional
michael@0:      * comments after a semicolon. The line must end with a CRLF: "a3; some
michael@0:      * comment\r\n" Positions the stream at the start of the next line.
michael@0:      *
michael@0:      * @param in The new input stream.
michael@0:      * @param required <tt>true<tt/> if a valid chunk must be present,
michael@0:      *                 <tt>false<tt/> otherwise.
michael@0:      *
michael@0:      * @return the chunk size as integer
michael@0:      *
michael@0:      * @throws IOException when the chunk size could not be parsed
michael@0:      */
michael@0:     private int getChunkSize() throws IOException {
michael@0:         int st = this.state;
michael@0:         switch (st) {
michael@0:         case CHUNK_CRLF:
michael@0:             this.buffer.clear();
michael@0:             int i = this.in.readLine(this.buffer);
michael@0:             if (i == -1) {
michael@0:                 return 0;
michael@0:             }
michael@0:             if (!this.buffer.isEmpty()) {
michael@0:                 throw new MalformedChunkCodingException(
michael@0:                     "Unexpected content at the end of chunk");
michael@0:             }
michael@0:             state = CHUNK_LEN;
michael@0:             //$FALL-THROUGH$
michael@0:         case CHUNK_LEN:
michael@0:             this.buffer.clear();
michael@0:             i = this.in.readLine(this.buffer);
michael@0:             if (i == -1) {
michael@0:                 return 0;
michael@0:             }
michael@0:             int separator = this.buffer.indexOf(';');
michael@0:             if (separator < 0) {
michael@0:                 separator = this.buffer.length();
michael@0:             }
michael@0:             try {
michael@0:                 return Integer.parseInt(this.buffer.substringTrimmed(0, separator), 16);
michael@0:             } catch (NumberFormatException e) {
michael@0:                 throw new MalformedChunkCodingException("Bad chunk header");
michael@0:             }
michael@0:         default:
michael@0:             throw new IllegalStateException("Inconsistent codec state");
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Reads and stores the Trailer headers.
michael@0:      * @throws IOException in case of an I/O error
michael@0:      */
michael@0:     private void parseTrailerHeaders() throws IOException {
michael@0:         try {
michael@0:             this.footers = AbstractMessageParser.parseHeaders
michael@0:                 (in, -1, -1, null);
michael@0:         } catch (HttpException e) {
michael@0:             IOException ioe = new MalformedChunkCodingException("Invalid footer: "
michael@0:                     + e.getMessage());
michael@0:             ExceptionUtils.initCause(ioe, e);
michael@0:             throw ioe;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Upon close, this reads the remainder of the chunked message,
michael@0:      * leaving the underlying socket at a position to start reading the
michael@0:      * next response without scanning.
michael@0:      * @throws IOException in case of an I/O error
michael@0:      */
michael@0:     public void close() throws IOException {
michael@0:         if (!closed) {
michael@0:             try {
michael@0:                 if (!eof) {
michael@0:                     // read and discard the remainder of the message
michael@0:                     byte buffer[] = new byte[BUFFER_SIZE];
michael@0:                     while (read(buffer) >= 0) {
michael@0:                     }
michael@0:                 }
michael@0:             } finally {
michael@0:                 eof = true;
michael@0:                 closed = true;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public Header[] getFooters() {
michael@0:         return (Header[])this.footers.clone();
michael@0:     }
michael@0: 
michael@0: }