/*
* ====================================================================
* 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.io;
import java.io.
IOException;
import java.io.
InputStream;
import org.apache.http.
ConnectionClosedException;
import org.apache.http.
Header;
import org.apache.http.
HttpException;
import org.apache.http.
MalformedChunkCodingException;
import org.apache.http.
TruncatedChunkException;
import org.apache.http.config.
MessageConstraints;
import org.apache.http.io.
BufferInfo;
import org.apache.http.io.
SessionInputBuffer;
import org.apache.http.util.
Args;
import org.apache.http.util.
CharArrayBuffer;
/**
* Implements chunked transfer coding. The content is received in small chunks.
* Entities transferred using this input stream can be of unlimited length.
* After the stream is read to the end, it provides access to the trailers,
* if any.
* <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 execution of subsequent HTTP 1.1
* requests, while not requiring the client to remember to read the entire
* contents of the response.
*
*
* @since 4.0
*
*/
public class
ChunkedInputStream extends
InputStream {
private static final int
CHUNK_LEN = 1;
private static final int
CHUNK_DATA = 2;
private static final int
CHUNK_CRLF = 3;
private static final int
CHUNK_INVALID =
Integer.
MAX_VALUE;
private static final int
BUFFER_SIZE = 2048;
/** The session input buffer */
private final
SessionInputBuffer in;
private final
CharArrayBuffer buffer;
private final
MessageConstraints constraints;
private int
state;
/** The chunk size */
private long
chunkSize;
/** The current position within the current chunk */
private long
pos;
/** True if we've reached the end of stream */
private boolean
eof = false;
/** True if this stream is closed */
private boolean
closed = false;
private
Header[]
footers = new
Header[] {};
/**
* Wraps session input stream and reads chunk coded input.
*
* @param in The session input buffer
* @param constraints Message constraints. If {@code null}
* {@link MessageConstraints#DEFAULT} will be used.
*
* @since 4.4
*/
public
ChunkedInputStream(final
SessionInputBuffer in, final
MessageConstraints constraints) {
super();
this.
in =
Args.
notNull(
in, "Session input buffer");
this.
pos = 0L;
this.
buffer = new
CharArrayBuffer(16);
this.
constraints =
constraints != null ?
constraints :
MessageConstraints.
DEFAULT;
this.
state =
CHUNK_LEN;
}
/**
* Wraps session input stream and reads chunk coded input.
*
* @param in The session input buffer
*/
public
ChunkedInputStream(final
SessionInputBuffer in) {
this(
in, null);
}
@
Override
public int
available() throws
IOException {
if (this.
in instanceof
BufferInfo) {
final int
len = ((
BufferInfo) this.
in).
length();
return (int)
Math.
min(
len, this.
chunkSize - this.
pos);
} else {
return 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 automatically 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 in case of an I/O error
*/
@
Override
public int
read() throws
IOException {
if (this.
closed) {
throw new
IOException("Attempted read from closed stream.");
}
if (this.
eof) {
return -1;
}
if (
state !=
CHUNK_DATA) {
nextChunk();
if (this.
eof) {
return -1;
}
}
final int
b =
in.
read();
if (
b != -1) {
pos++;
if (
pos >=
chunkSize) {
state =
CHUNK_CRLF;
}
}
return
b;
}
/**
* 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.
* @throws IOException in case of an I/O error
*/
@
Override
public int
read (final byte[]
b, final int
off, final int
len) throws
IOException {
if (
closed) {
throw new
IOException("Attempted read from closed stream.");
}
if (
eof) {
return -1;
}
if (
state !=
CHUNK_DATA) {
nextChunk();
if (
eof) {
return -1;
}
}
final int
bytesRead =
in.
read(
b,
off, (int)
Math.
min(
len,
chunkSize -
pos));
if (
bytesRead != -1) {
pos +=
bytesRead;
if (
pos >=
chunkSize) {
state =
CHUNK_CRLF;
}
return
bytesRead;
} else {
eof = true;
throw new
TruncatedChunkException("Truncated chunk "
+ "( expected size: " +
chunkSize
+ "; actual size: " +
pos + ")");
}
}
/**
* 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.
* @throws IOException in case of an I/O error
*/
@
Override
public int
read (final byte[]
b) throws
IOException {
return
read(
b, 0,
b.length);
}
/**
* Read the next chunk.
* @throws IOException in case of an I/O error
*/
private void
nextChunk() throws
IOException {
if (
state ==
CHUNK_INVALID) {
throw new
MalformedChunkCodingException("Corrupt data stream");
}
try {
chunkSize =
getChunkSize();
if (
chunkSize < 0L) {
throw new
MalformedChunkCodingException("Negative chunk size");
}
state =
CHUNK_DATA;
pos = 0L;
if (
chunkSize == 0L) {
eof = true;
parseTrailerHeaders();
}
} catch (final
MalformedChunkCodingException ex) {
state =
CHUNK_INVALID;
throw
ex;
}
}
/**
* 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.
*/
private long
getChunkSize() throws
IOException {
final int
st = this.
state;
switch (
st) {
case
CHUNK_CRLF:
this.
buffer.
clear();
final int
bytesRead1 = this.
in.
readLine(this.
buffer);
if (
bytesRead1 == -1) {
throw new
MalformedChunkCodingException(
"CRLF expected at end of chunk");
}
if (!this.
buffer.
isEmpty()) {
throw new
MalformedChunkCodingException(
"Unexpected content at the end of chunk");
}
state =
CHUNK_LEN;
//$FALL-THROUGH$
case
CHUNK_LEN:
this.
buffer.
clear();
final int
bytesRead2 = this.
in.
readLine(this.
buffer);
if (
bytesRead2 == -1) {
throw new
ConnectionClosedException("Premature end of chunk coded message body: " +
"closing chunk expected");
}
int
separator = this.
buffer.
indexOf(';');
if (
separator < 0) {
separator = this.
buffer.
length();
}
final
String s = this.
buffer.
substringTrimmed(0,
separator);
try {
return
Long.
parseLong(
s, 16);
} catch (final
NumberFormatException e) {
throw new
MalformedChunkCodingException("Bad chunk header: " +
s);
}
default:
throw new
IllegalStateException("Inconsistent codec state");
}
}
/**
* Reads and stores the Trailer headers.
* @throws IOException in case of an I/O error
*/
private void
parseTrailerHeaders() throws
IOException {
try {
this.
footers =
AbstractMessageParser.
parseHeaders(
in,
constraints.
getMaxHeaderCount(),
constraints.
getMaxLineLength(),
null);
} catch (final
HttpException ex) {
final
IOException ioe = new
MalformedChunkCodingException("Invalid footer: "
+
ex.
getMessage());
ioe.
initCause(
ex);
throw
ioe;
}
}
/**
* 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 in case of an I/O error
*/
@
Override
public void
close() throws
IOException {
if (!
closed) {
try {
if (!
eof &&
state !=
CHUNK_INVALID) {
// read and discard the remainder of the message
final byte
buff[] = new byte[
BUFFER_SIZE];
while (
read(
buff) >= 0) {
}
}
} finally {
eof = true;
closed = true;
}
}
}
public
Header[]
getFooters() {
return this.
footers.
clone();
}
}