/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed 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.
*/
package com.squareup.okhttp.internal.http;
import com.squareup.okhttp.Connection;
import com.squareup.okhttp.internal.AbstractOutputStream;
import com.squareup.okhttp.internal.Util;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.CacheRequest;
import java.net.ProtocolException;
import java.net.Socket;
import static com.squareup.okhttp.internal.Util.checkOffsetAndCount;
public final class HttpTransport implements Transport {
/**
* The timeout to use while discarding a stream of input data. Since this is
* used for connection reuse, this timeout should be significantly less than
* the time it takes to establish a new connection.
*/
private static final int DISCARD_STREAM_TIMEOUT_MILLIS = 100;
public static final int DEFAULT_CHUNK_LENGTH = 1024;
private final HttpEngine httpEngine;
private final InputStream socketIn;
private final OutputStream socketOut;
/**
* This stream buffers the request headers and the request body when their
* combined size is less than MAX_REQUEST_BUFFER_LENGTH. By combining them
* we can save socket writes, which in turn saves a packet transmission.
* This is socketOut if the request size is large or unknown.
*/
private OutputStream requestOut;
public HttpTransport(HttpEngine httpEngine, OutputStream outputStream, InputStream inputStream) {
this.httpEngine = httpEngine;
this.socketOut = outputStream;
this.requestOut = outputStream;
this.socketIn = inputStream;
}
@Override public OutputStream createRequestBody() throws IOException {
boolean chunked = httpEngine.requestHeaders.isChunked();
if (!chunked
&& httpEngine.policy.getChunkLength() > 0
&& httpEngine.connection.getHttpMinorVersion() != 0) {
httpEngine.requestHeaders.setChunked();
chunked = true;
}
// Stream a request body of unknown length.
if (chunked) {
int chunkLength = httpEngine.policy.getChunkLength();
if (chunkLength == -1) {
chunkLength = DEFAULT_CHUNK_LENGTH;
}
writeRequestHeaders();
return new ChunkedOutputStream(requestOut, chunkLength);
}
// Stream a request body of a known length.
long fixedContentLength = httpEngine.policy.getFixedContentLength();
if (fixedContentLength != -1) {
httpEngine.requestHeaders.setContentLength(fixedContentLength);
writeRequestHeaders();
return new FixedLengthOutputStream(requestOut, fixedContentLength);
}
long contentLength = httpEngine.requestHeaders.getContentLength();
if (contentLength > Integer.MAX_VALUE) {
throw new IllegalArgumentException("Use setFixedLengthStreamingMode() or "
+ "setChunkedStreamingMode() for requests larger than 2 GiB.");
}
// Buffer a request body of a known length.
if (contentLength != -1) {
writeRequestHeaders();
return new RetryableOutputStream((int) contentLength);
}
// Buffer a request body of an unknown length. Don't write request
// headers until the entire body is ready; otherwise we can't set the
// Content-Length header correctly.
return new RetryableOutputStream();
}
@Override public void flushRequest() throws IOException {
requestOut.flush();
requestOut = socketOut;
}
@Override public void writeRequestBody(RetryableOutputStream requestBody) throws IOException {
requestBody.writeToSocket(requestOut);
}
/**
* Prepares the HTTP headers and sends them to the server.
*
* <p>For streaming requests with a body, headers must be prepared
* <strong>before</strong> the output stream has been written to. Otherwise
* the body would need to be buffered!
*
* <p>For non-streaming requests with a body, headers must be prepared
* <strong>after</strong> the output stream has been written to and closed.
* This ensures that the {@code Content-Length} header field receives the
* proper value.
*/
public void writeRequestHeaders() throws IOException {
httpEngine.writingRequestHeaders();
RawHeaders headersToSend = httpEngine.requestHeaders.getHeaders();
byte[] bytes = headersToSend.toBytes();
requestOut.write(bytes);
}
@Override public ResponseHeaders readResponseHeaders() throws IOException {
RawHeaders rawHeaders = RawHeaders.fromBytes(socketIn);
httpEngine.connection.setHttpMinorVersion(rawHeaders.getHttpMinorVersion());
httpEngine.receiveHeaders(rawHeaders);
ResponseHeaders headers = new ResponseHeaders(httpEngine.uri, rawHeaders);
headers.setTransport("http/1.1");
return headers;
}
public boolean makeReusable(boolean streamCanceled, OutputStream requestBodyOut,
InputStream responseBodyIn) {
if (streamCanceled) {
return false;
}
// We cannot reuse sockets that have incomplete output.
if (requestBodyOut != null && !((AbstractOutputStream) requestBodyOut).isClosed()) {
return false;
}
// If the request specified that the connection shouldn't be reused, don't reuse it.
if (httpEngine.requestHeaders.hasConnectionClose()) {
return false;
}
// If the response specified that the connection shouldn't be reused, don't reuse it.
if (httpEngine.responseHeaders != null && httpEngine.responseHeaders.hasConnectionClose()) {
return false;
}
if (responseBodyIn instanceof UnknownLengthHttpInputStream) {
return false;
}
if (responseBodyIn != null) {
return discardStream(httpEngine, responseBodyIn);
}
return true;
}
/**
* Discards the response body so that the connection can be reused. This
* needs to be done judiciously, since it delays the current request in
* order to speed up a potential future request that may never occur.
*
* <p>A stream may be discarded to encourage response caching (a response
* cannot be cached unless it is consumed completely) or to enable connection
* reuse.
*/
private static boolean discardStream(HttpEngine httpEngine, InputStream responseBodyIn) {
Connection connection = httpEngine.connection;
if (connection == null) return false;
Socket socket = connection.getSocket();
if (socket == null) return false;
try {
int socketTimeout = socket.getSoTimeout();
socket.setSoTimeout(DISCARD_STREAM_TIMEOUT_MILLIS);
try {
Util.skipAll(responseBodyIn);
return true;
} finally {
socket.setSoTimeout(socketTimeout);
}
} catch (IOException e) {
return false;
}
}
@Override public InputStream getTransferStream(CacheRequest cacheRequest) throws IOException {
if (!httpEngine.hasResponseBody()) {
return new FixedLengthInputStream(socketIn, cacheRequest, httpEngine, 0);
}
if (httpEngine.responseHeaders.isChunked()) {
return new ChunkedInputStream(socketIn, cacheRequest, this);
}
if (httpEngine.responseHeaders.getContentLength() != -1) {
return new FixedLengthInputStream(socketIn, cacheRequest, httpEngine,
httpEngine.responseHeaders.getContentLength());
}
// Wrap the input stream from the connection (rather than just returning
// "socketIn" directly here), so that we can control its use after the
// reference escapes.
return new UnknownLengthHttpInputStream(socketIn, cacheRequest, httpEngine);
}
/** An HTTP body with a fixed length known in advance. */
private static final class FixedLengthOutputStream extends AbstractOutputStream {
private final OutputStream socketOut;
private long bytesRemaining;
private FixedLengthOutputStream(OutputStream socketOut, long bytesRemaining) {
this.socketOut = socketOut;
this.bytesRemaining = bytesRemaining;
}
@Override public void write(byte[] buffer, int offset, int count) throws IOException {
checkNotClosed();
checkOffsetAndCount(buffer.length, offset, count);
if (count > bytesRemaining) {
throw new ProtocolException("expected " + bytesRemaining + " bytes but received " + count);
}
socketOut.write(buffer, offset, count);
bytesRemaining -= count;
}
@Override public void flush() throws IOException {
if (closed) {
return; // don't throw; this stream might have been closed on the caller's behalf
}
socketOut.flush();
}
@Override public void close() throws IOException {
if (closed) {
return;
}
closed = true;
if (bytesRemaining > 0) {
throw new ProtocolException("unexpected end of stream");
}
}
}
/**
* An HTTP body with alternating chunk sizes and chunk bodies. Chunks are
* buffered until {@code maxChunkLength} bytes are ready, at which point the
* chunk is written and the buffer is cleared.
*/
private static final class ChunkedOutputStream extends AbstractOutputStream {
private static final byte[] CRLF = { '\r', '\n' };
private static final byte[] HEX_DIGITS = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
private static final byte[] FINAL_CHUNK = new byte[] { '0', '\r', '\n', '\r', '\n' };
/** Scratch space for up to 8 hex digits, and then a constant CRLF. */
private final byte[] hex = { 0, 0, 0, 0, 0, 0, 0, 0, '\r', '\n' };
private final OutputStream socketOut;
private final int maxChunkLength;
private final ByteArrayOutputStream bufferedChunk;
private ChunkedOutputStream(OutputStream socketOut, int maxChunkLength) {
this.socketOut = socketOut;
this.maxChunkLength = Math.max(1, dataLength(maxChunkLength));
this.bufferedChunk = new ByteArrayOutputStream(maxChunkLength);
}
/**
* Returns the amount of data that can be transmitted in a chunk whose total
* length (data+headers) is {@code dataPlusHeaderLength}. This is presumably
* useful to match sizes with wire-protocol packets.
*/
private int dataLength(int dataPlusHeaderLength) {
int headerLength = 4; // "\r\n" after the size plus another "\r\n" after the data
for (int i = dataPlusHeaderLength - headerLength; i > 0; i >>= 4) {
headerLength++;
}
return dataPlusHeaderLength - headerLength;
}
@Override public synchronized void write(byte[] buffer, int offset, int count)
throws IOException {
checkNotClosed();
checkOffsetAndCount(buffer.length, offset, count);
while (count > 0) {
int numBytesWritten;
if (bufferedChunk.size() > 0 || count < maxChunkLength) {
// fill the buffered chunk and then maybe write that to the stream
numBytesWritten = Math.min(count, maxChunkLength - bufferedChunk.size());
// TODO: skip unnecessary copies from buffer->bufferedChunk?
bufferedChunk.write(buffer, offset, numBytesWritten);
if (bufferedChunk.size() == maxChunkLength) {
writeBufferedChunkToSocket();
}
} else {
// write a single chunk of size maxChunkLength to the stream
numBytesWritten = maxChunkLength;
writeHex(numBytesWritten);
socketOut.write(buffer, offset, numBytesWritten);
socketOut.write(CRLF);
}
offset += numBytesWritten;
count -= numBytesWritten;
}
}
/**
* Equivalent to, but cheaper than writing Integer.toHexString().getBytes()
* followed by CRLF.
*/
private void writeHex(int i) throws IOException {
int cursor = 8;
do {
hex[--cursor] = HEX_DIGITS[i & 0xf];
} while ((i >>>= 4) != 0);
socketOut.write(hex, cursor, hex.length - cursor);
}
@Override public synchronized void flush() throws IOException {
if (closed) {
return; // don't throw; this stream might have been closed on the caller's behalf
}
writeBufferedChunkToSocket();
socketOut.flush();
}
@Override public synchronized void close() throws IOException {
if (closed) {
return;
}
closed = true;
writeBufferedChunkToSocket();
socketOut.write(FINAL_CHUNK);
}
private void writeBufferedChunkToSocket() throws IOException {
int size = bufferedChunk.size();
if (size <= 0) {
return;
}
writeHex(size);
bufferedChunk.writeTo(socketOut);
bufferedChunk.reset();
socketOut.write(CRLF);
}
}
/** An HTTP body with a fixed length specified in advance. */
private static class FixedLengthInputStream extends AbstractHttpInputStream {
private long bytesRemaining;
public FixedLengthInputStream(InputStream is, CacheRequest cacheRequest, HttpEngine httpEngine,
long length) throws IOException {
super(is, httpEngine, cacheRequest);
bytesRemaining = length;
if (bytesRemaining == 0) {
endOfInput();
}
}
@Override public int read(byte[] buffer, int offset, int count) throws IOException {
checkOffsetAndCount(buffer.length, offset, count);
checkNotClosed();
if (bytesRemaining == 0) {
return -1;
}
int read = in.read(buffer, offset, (int) Math.min(count, bytesRemaining));
if (read == -1) {
unexpectedEndOfInput(); // the server didn't supply the promised content length
throw new ProtocolException("unexpected end of stream");
}
bytesRemaining -= read;
cacheWrite(buffer, offset, read);
if (bytesRemaining == 0) {
endOfInput();
}
return read;
}
@Override public int available() throws IOException {
checkNotClosed();
return bytesRemaining == 0 ? 0 : (int) Math.min(in.available(), bytesRemaining);
}
@Override public void close() throws IOException {
if (closed) {
return;
}
if (bytesRemaining != 0 && !discardStream(httpEngine, this)) {
unexpectedEndOfInput();
}
closed = true;
}
}
/** An HTTP body with alternating chunk sizes and chunk bodies. */
private static class ChunkedInputStream extends AbstractHttpInputStream {
private static final int NO_CHUNK_YET = -1;
private final HttpTransport transport;
private int bytesRemainingInChunk = NO_CHUNK_YET;
private boolean hasMoreChunks = true;
ChunkedInputStream(InputStream is, CacheRequest cacheRequest, HttpTransport transport)
throws IOException {
super(is, transport.httpEngine, cacheRequest);
this.transport = transport;
}
@Override public int read(byte[] buffer, int offset, int count) throws IOException {
checkOffsetAndCount(buffer.length, offset, count);
checkNotClosed();
if (!hasMoreChunks) {
return -1;
}
if (bytesRemainingInChunk == 0 || bytesRemainingInChunk == NO_CHUNK_YET) {
readChunkSize();
if (!hasMoreChunks) {
return -1;
}
}
int read = in.read(buffer, offset, Math.min(count, bytesRemainingInChunk));
if (read == -1) {
unexpectedEndOfInput(); // the server didn't supply the promised chunk length
throw new IOException("unexpected end of stream");
}
bytesRemainingInChunk -= read;
cacheWrite(buffer, offset, read);
return read;
}
private void readChunkSize() throws IOException {
// read the suffix of the previous chunk
if (bytesRemainingInChunk != NO_CHUNK_YET) {
Util.readAsciiLine(in);
}
String chunkSizeString = Util.readAsciiLine(in);
int index = chunkSizeString.indexOf(";");
if (index != -1) {
chunkSizeString = chunkSizeString.substring(0, index);
}
try {
bytesRemainingInChunk = Integer.parseInt(chunkSizeString.trim(), 16);
} catch (NumberFormatException e) {
throw new ProtocolException("Expected a hex chunk size but was " + chunkSizeString);
}
if (bytesRemainingInChunk == 0) {
hasMoreChunks = false;
RawHeaders rawResponseHeaders = httpEngine.responseHeaders.getHeaders();
RawHeaders.readHeaders(transport.socketIn, rawResponseHeaders);
httpEngine.receiveHeaders(rawResponseHeaders);
endOfInput();
}
}
@Override public int available() throws IOException {
checkNotClosed();
if (!hasMoreChunks || bytesRemainingInChunk == NO_CHUNK_YET) {
return 0;
}
return Math.min(in.available(), bytesRemainingInChunk);
}
@Override public void close() throws IOException {
if (closed) {
return;
}
if (hasMoreChunks && !discardStream(httpEngine, this)) {
unexpectedEndOfInput();
}
closed = true;
}
}
}