/* ====================================================================
*
* 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/>.
*
*/
/*
* This file was imported from apache http client 3.1 library and modified
* to work for the YaCy http server when http client library use was migrated
* to apache http components 4.0
* by Michael Christen, 20.09.2010
*/
package de.anomic.http.server;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
/**
* <p>Transparently coalesces chunks of a HTTP stream that uses
* Transfer-Encoding chunked.</p>
*
* <p>Note that this class NEVER closes the underlying stream, even when close
* gets called. Instead, it will read until the "end" of its chunking on close,
* which allows for the seamless invocation of subsequent HTTP 1.1 calls, while
* not requiring the client to remember to read the entire contents of the
* response.</p>
*
* @author Ortwin Glueck
* @author Sean C. Sullivan
* @author Martin Elwin
* @author Eric Johnson
* @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
* @author Michael Becke
* @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
*
* @since 2.0
*
*/
public class ChunkedInputStream extends InputStream {
/** The inputstream that we're wrapping */
private final InputStream in;
/** The chunk size */
private int chunkSize;
/** The current position within the current chunk */
private int pos;
/** True if we'are at the beginning of stream */
private boolean bof = true;
/** True if we've reached the end of stream */
private boolean eof = false;
/** True if this stream is closed */
private boolean closed = false;
/**
* ChunkedInputStream constructor
*
* @param in the raw input stream
*
* @throws IOException If an IO error occurs
*/
public ChunkedInputStream(final InputStream in) throws IOException {
if (in == null) {
throw new IllegalArgumentException("InputStream parameter may not be null");
}
this.in = in;
this.pos = 0;
}
/**
* <p> Returns all the data in a chunked stream in coalesced form. A chunk
* is followed by a CRLF. The method returns -1 as soon as a chunksize of 0
* is detected.</p>
*
* <p> Trailer headers are read automcatically at the end of the stream and
* can be obtained with the getResponseFooters() method.</p>
*
* @return -1 of the end of the stream has been reached or the next data
* byte
* @throws IOException If an IO problem occurs
*
* @see HttpMethod#getResponseFooters()
*/
@Override
public int read() throws IOException {
if (this.closed) {
throw new IOException("Attempted read from closed stream.");
}
if (this.eof) {
return -1;
}
if (this.pos >= this.chunkSize) {
nextChunk();
if (this.eof) {
return -1;
}
}
this.pos++;
return this.in.read();
}
/**
* Read some bytes from the stream.
* @param b The byte array that will hold the contents from the stream.
* @param off The offset into the byte array at which bytes will start to be
* placed.
* @param len the maximum number of bytes that can be returned.
* @return The number of bytes returned or -1 if the end of stream has been
* reached.
* @see java.io.InputStream#read(byte[], int, int)
* @throws IOException if an IO problem occurs.
*/
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (this.closed) throw new IOException("Attempted read from closed stream.");
if (this.eof) return -1;
if (this.pos >= this.chunkSize) {
nextChunk();
if (this.eof) {
return -1;
}
}
len = Math.min(len, this.chunkSize - this.pos);
int count = this.in.read(b, off, len);
this.pos += count;
return count;
}
/**
* Read some bytes from the stream.
* @param b The byte array that will hold the contents from the stream.
* @return The number of bytes returned or -1 if the end of stream has been
* reached.
* @see java.io.InputStream#read(byte[])
* @throws IOException if an IO problem occurs.
*/
@Override
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
/**
* Read the CRLF terminator.
* @throws IOException If an IO error occurs.
*/
private void readCRLF() throws IOException {
int cr = this.in.read();
if (cr != '\r') throw new IOException("CRLF expected at end of chunk: cr != " + cr);
int lf = this.in.read();
if (lf != '\n') throw new IOException("CRLF expected at end of chunk: lf != " + lf);
}
/**
* Read the next chunk.
* @throws IOException If an IO error occurs.
*/
private void nextChunk() throws IOException {
if (!this.bof) readCRLF();
this.chunkSize = getChunkSizeFromInputStream(this.in);
this.bof = false;
this.pos = 0;
if (this.chunkSize == 0) {
this.eof = true;
skipTrailerHeaders();
}
}
/**
* Expects the stream to start with a chunksize in hex with optional
* comments after a semicolon. The line must end with a CRLF: "a3; some
* comment\r\n" Positions the stream at the start of the next line.
*
* @param in The new input stream.
* @param required <tt>true<tt/> if a valid chunk must be present,
* <tt>false<tt/> otherwise.
*
* @return the chunk size as integer
*
* @throws IOException when the chunk size could not be parsed
*/
private static int getChunkSizeFromInputStream(final InputStream in)
throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
// States: 0=normal, 1=\r was scanned, 2=inside quoted string, -1=end
int state = 0;
while (state != -1) {
int b = in.read();
if (b == -1) {
throw new IOException("chunked stream ended unexpectedly");
}
switch (state) {
case 0:
switch (b) {
case '\r':
state = 1;
break;
case '\"':
state = 2;
baos.write(b);
break;
default:
baos.write(b);
}
break;
case 1:
if (b == '\n') {
state = -1;
} else {
// this was not CRLF
throw new IOException("Protocol violation: Unexpected"
+ " single newline character in chunk size");
}
break;
case 2:
switch (b) {
case '\\':
b = in.read();
baos.write(b);
break;
case '\"':
state = 0;
baos.write(b);
break;
default:
baos.write(b);
}
break;
default: throw new RuntimeException("assertion failed");
}
}
//parse data
String dataString = getAsciiString(baos.toByteArray());
int separator = dataString.indexOf(';');
dataString = (separator > 0)
? dataString.substring(0, separator).trim()
: dataString.trim();
int result;
try {
result = Integer.parseInt(dataString.trim(), 16);
} catch (NumberFormatException e) {
throw new IOException ("Bad chunk size: " + dataString);
}
return result;
}
/**
* Converts the byte array of ASCII characters to a string. This method is
* to be used when decoding content of HTTP elements (such as response
* headers)
*
* @param data the byte array to be encoded
* @return The string representation of the byte array
*
* @since 3.0
*/
private static String getAsciiString(final byte[] data) throws IOException {
if (data == null) {
throw new IllegalArgumentException("Parameter may not be null");
}
try {
return new String(data, 0, data.length, "US-ASCII");
} catch (UnsupportedEncodingException e) {
throw new IOException("HttpClient requires ASCII support");
}
}
/**
* Reads and stores the Trailer headers.
* @throws IOException If an IO problem occurs
*/
private void skipTrailerHeaders() throws IOException {
for (; ;) {
String line = readLine(this.in, "US-ASCII");
if ((line == null) || (line.trim().length() < 1)) break;
}
}
/**
* Read up to <tt>"\n"</tt> from an (unchunked) input stream.
* If the stream ends before the line terminator is found,
* the last part of the string will still be returned.
* If no input data available, <code>null</code> is returned.
*
* @param inputStream the stream to read from
* @param charset charset of HTTP protocol elements
*
* @throws IOException if an I/O problem occurs
* @return a line from the stream
*
* @since 3.0
*/
private static String readLine(InputStream inputStream, String charset) throws IOException {
byte[] rawdata = readRawLine(inputStream);
if (rawdata == null) {
return null;
}
// strip CR and LF from the end
int len = rawdata.length;
int offset = 0;
if (len > 0) {
if (rawdata[len - 1] == '\n') {
offset++;
if (len > 1) {
if (rawdata[len - 2] == '\r') {
offset++;
}
}
}
}
final String result = getString(rawdata, 0, len - offset, charset);
return result;
}
/**
* Converts the byte array of HTTP content characters to a string. If
* the specified charset is not supported, default system encoding
* is used.
*
* @param data the byte array to be encoded
* @param offset the index of the first byte to encode
* @param length the number of bytes to encode
* @param charset the desired character encoding
* @return The result of the conversion.
*
* @since 3.0
*/
private static String getString(
final byte[] data,
int offset,
int length,
String charset
) {
if (data == null) {
throw new IllegalArgumentException("Parameter may not be null");
}
if (charset == null || charset.length() == 0) {
throw new IllegalArgumentException("charset may not be null or empty");
}
try {
return new String(data, offset, length, charset);
} catch (UnsupportedEncodingException e) {
return new String(data, offset, length);
}
}
/**
* Return byte array from an (unchunked) input stream.
* Stop reading when <tt>"\n"</tt> terminator encountered
* If the stream ends before the line terminator is found,
* the last part of the string will still be returned.
* If no input data available, <code>null</code> is returned.
*
* @param inputStream the stream to read from
*
* @throws IOException if an I/O problem occurs
* @return a byte array from the stream
*/
private static byte[] readRawLine(InputStream inputStream) throws IOException {
ByteArrayOutputStream buf = new ByteArrayOutputStream();
int ch;
while ((ch = inputStream.read()) >= 0) {
buf.write(ch);
if (ch == '\n') { // be tolerant (RFC-2616 Section 19.3)
break;
}
}
if (buf.size() == 0) {
return null;
}
return buf.toByteArray();
}
/**
* Upon close, this reads the remainder of the chunked message,
* leaving the underlying socket at a position to start reading the
* next response without scanning.
* @throws IOException If an IO problem occurs.
*/
@Override
public synchronized void close() throws IOException {
if (!this.closed) {
try {
if (!this.eof) {
exhaustInputStream(this);
}
} finally {
this.eof = true;
this.closed = true;
}
}
}
/**
* Exhaust an input stream, reading until EOF has been encountered.
*
* <p>Note that this function is intended as a non-public utility.
* This is a little weird, but it seemed silly to make a utility
* class for this one function, so instead it is just static and
* shared that way.</p>
*
* @param inStream The {@link InputStream} to exhaust.
* @throws IOException If an IO problem occurs
*/
static void exhaustInputStream(InputStream inStream) throws IOException {
// read and discard the remainder of the message
byte buffer[] = new byte[1024];
while (inStream.read(buffer) >= 0) {
;
}
}
}