/*
* $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0.1/httpcore-nio/src/main/java/org/apache/http/impl/nio/codecs/ChunkDecoder.java $
* $Revision: 777111 $
* $Date: 2009-05-21 15:22:39 +0200 (Thu, 21 May 2009) $
*
* ====================================================================
* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.impl.nio.codecs;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.Header;
import org.apache.http.MalformedChunkCodingException;
import org.apache.http.message.BufferedHeader;
import org.apache.http.nio.reactor.SessionInputBuffer;
import org.apache.http.impl.io.HttpTransportMetricsImpl;
import org.apache.http.ParseException;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.CharArrayBuffer;
/**
* Implements chunked transfer coding. The content is received in small chunks.
* Entities transferred using this encoder can be of unlimited length.
*
*
* @version $Revision: 777111 $
*
* @since 4.0
*/
public class ChunkDecoder extends AbstractContentDecoder {
private static final int READ_CONTENT = 0;
private static final int READ_FOOTERS = 1;
private static final int COMPLETED = 2;
private int state;
private boolean endOfChunk;
private boolean endOfStream;
private CharArrayBuffer lineBuf;
private int chunkSize;
private int pos;
private final List<CharArrayBuffer> trailerBufs;
private Header[] footers;
public ChunkDecoder(
final ReadableByteChannel channel,
final SessionInputBuffer buffer,
final HttpTransportMetricsImpl metrics) {
super(channel, buffer, metrics);
this.state = READ_CONTENT;
this.chunkSize = -1;
this.pos = 0;
this.endOfChunk = false;
this.endOfStream = false;
this.trailerBufs = new ArrayList<CharArrayBuffer>();
}
private void readChunkHead() throws IOException {
if (this.endOfChunk) {
if (this.buffer.length() < 2) {
return;
}
int cr = this.buffer.read();
int lf = this.buffer.read();
if (cr != HTTP.CR || lf != HTTP.LF) {
throw new MalformedChunkCodingException("CRLF expected at end of chunk");
}
this.endOfChunk = false;
}
if (this.lineBuf == null) {
this.lineBuf = new CharArrayBuffer(32);
} else {
this.lineBuf.clear();
}
if (this.buffer.readLine(this.lineBuf, this.endOfStream)) {
int separator = this.lineBuf.indexOf(';');
if (separator < 0) {
separator = this.lineBuf.length();
}
try {
String s = this.lineBuf.substringTrimmed(0, separator);
this.chunkSize = Integer.parseInt(s, 16);
} catch (NumberFormatException e) {
throw new MalformedChunkCodingException("Bad chunk header");
}
this.pos = 0;
}
}
private void parseHeader() {
CharArrayBuffer current = this.lineBuf;
int count = this.trailerBufs.size();
if ((this.lineBuf.charAt(0) == ' ' || this.lineBuf.charAt(0) == '\t') && count > 0) {
// Handle folded header line
CharArrayBuffer previous = this.trailerBufs.get(count - 1);
int i = 0;
while (i < current.length()) {
char ch = current.charAt(i);
if (ch != ' ' && ch != '\t') {
break;
}
i++;
}
previous.append(' ');
previous.append(current, i, current.length() - i);
} else {
this.trailerBufs.add(current);
this.lineBuf = null;
}
}
private void processFooters() throws IOException {
int count = this.trailerBufs.size();
if (count > 0) {
this.footers = new Header[this.trailerBufs.size()];
for (int i = 0; i < this.trailerBufs.size(); i++) {
CharArrayBuffer buffer = this.trailerBufs.get(i);
try {
this.footers[i] = new BufferedHeader(buffer);
} catch (ParseException ex) {
throw new IOException(ex.getMessage());
}
}
}
this.trailerBufs.clear();
}
public int read(final ByteBuffer dst) throws IOException {
if (dst == null) {
throw new IllegalArgumentException("Byte buffer may not be null");
}
if (this.state == COMPLETED) {
return -1;
}
int totalRead = 0;
while (this.state != COMPLETED) {
if (!this.buffer.hasData() || this.chunkSize == -1) {
int bytesRead = this.buffer.fill(this.channel);
if (bytesRead > 0) {
this.metrics.incrementBytesTransferred(bytesRead);
}
if (bytesRead == -1) {
this.endOfStream = true;
}
}
switch (this.state) {
case READ_CONTENT:
if (this.chunkSize == -1) {
readChunkHead();
if (this.chunkSize == -1) {
// Unable to read a chunk head
if (this.endOfStream) {
this.state = COMPLETED;
this.completed = true;
}
return totalRead;
}
if (this.chunkSize == 0) {
// Last chunk. Read footers
this.chunkSize = -1;
this.state = READ_FOOTERS;
break;
}
}
int maxLen = this.chunkSize - this.pos;
int len = this.buffer.read(dst, maxLen);
if (len > 0) {
this.pos += len;
totalRead += len;
} else {
if (!this.buffer.hasData() && this.endOfStream) {
this.state = COMPLETED;
this.completed = true;
throw new MalformedChunkCodingException("Truncated chunk "
+ "( expected size: " + this.chunkSize
+ "; actual size: " + this.pos + ")");
}
}
if (this.pos == this.chunkSize) {
// At the end of the chunk
this.chunkSize = -1;
this.pos = 0;
this.endOfChunk = true;
break;
}
return totalRead;
case READ_FOOTERS:
if (this.lineBuf == null) {
this.lineBuf = new CharArrayBuffer(32);
} else {
this.lineBuf.clear();
}
if (!this.buffer.readLine(this.lineBuf, this.endOfStream)) {
// Unable to read a footer
if (this.endOfStream) {
this.state = COMPLETED;
this.completed = true;
}
return totalRead;
}
if (this.lineBuf.length() > 0) {
parseHeader();
} else {
this.state = COMPLETED;
this.completed = true;
processFooters();
}
break;
}
}
return totalRead;
}
public Header[] getFooters() {
if (this.footers != null) {
return this.footers.clone();
} else {
return new Header[] {};
}
}
@Override
public String toString() {
StringBuffer buffer = new StringBuffer();
buffer.append("[chunk-coded; completed: ");
buffer.append(this.completed);
buffer.append("]");
return buffer.toString();
}
}