Http11OutputBuffer.java
/*
* 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.
*/
package org.apache.coyote.http11;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;
import org.apache.coyote.ActionCode;
import org.apache.coyote.CloseNowException;
import org.apache.coyote.Response;
import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.net.SocketWrapperBase;
import org.apache.tomcat.util.res.StringManager;
/**
* Provides buffering for the HTTP headers (allowing responses to be reset before they have been committed) and the link
* to the Socket for writing the headers (once committed) and the response body. Note that buffering of the response
* body happens at a higher level.
*/
public class Http11OutputBuffer implements HttpOutputBuffer {
// -------------------------------------------------------------- Variables
/**
* The string manager for this package.
*/
protected static final StringManager sm = StringManager.getManager(Http11OutputBuffer.class);
// ----------------------------------------------------- Instance Variables
/**
* Associated Coyote response.
*/
protected final Response response;
private volatile boolean ackSent = false;
/**
* Finished flag.
*/
protected boolean responseFinished;
/**
* The buffer used for header composition.
*/
protected final ByteBuffer headerBuffer;
/**
* Filter library for processing the response body.
*/
protected OutputFilter[] filterLibrary;
/**
* Active filters for the current request.
*/
protected OutputFilter[] activeFilters;
/**
* Index of the last active filter.
*/
protected int lastActiveFilter;
/**
* Underlying output buffer.
*/
protected HttpOutputBuffer outputStreamOutputBuffer;
/**
* Wrapper for socket where data will be written to.
*/
protected SocketWrapperBase<?> socketWrapper;
/**
* Bytes written to client for the current request
*/
protected long byteCount = 0;
protected Http11OutputBuffer(Response response, int headerBufferSize) {
this.response = response;
headerBuffer = ByteBuffer.allocate(headerBufferSize);
filterLibrary = new OutputFilter[0];
activeFilters = new OutputFilter[0];
lastActiveFilter = -1;
responseFinished = false;
outputStreamOutputBuffer = new SocketOutputBuffer();
}
// ------------------------------------------------------------- Properties
/**
* Add an output filter to the filter library. Note that calling this method resets the currently active filters to
* none.
*
* @param filter The filter to add
*/
public void addFilter(OutputFilter filter) {
OutputFilter[] newFilterLibrary = Arrays.copyOf(filterLibrary, filterLibrary.length + 1);
newFilterLibrary[filterLibrary.length] = filter;
filterLibrary = newFilterLibrary;
activeFilters = new OutputFilter[filterLibrary.length];
}
/**
* Get filters.
*
* @return The current filter library containing all possible filters
*/
public OutputFilter[] getFilters() {
return filterLibrary;
}
/**
* Add an output filter to the active filters for the current response.
* <p>
* The filter does not have to be present in {@link #getFilters()}.
* <p>
* A filter can only be added to a response once. If the filter has already been added to this response then this
* method will be a NO-OP.
*
* @param filter The filter to add
*/
public void addActiveFilter(OutputFilter filter) {
if (lastActiveFilter == -1) {
filter.setBuffer(outputStreamOutputBuffer);
} else {
for (int i = 0; i <= lastActiveFilter; i++) {
if (activeFilters[i] == filter) {
return;
}
}
filter.setBuffer(activeFilters[lastActiveFilter]);
}
activeFilters[++lastActiveFilter] = filter;
filter.setResponse(response);
}
// --------------------------------------------------- OutputBuffer Methods
@Override
public int doWrite(ByteBuffer chunk) throws IOException {
if (!response.isCommitted()) {
// Send the connector a request for commit. The connector should
// then validate the headers, send them (using sendHeaders) and
// set the filters accordingly.
response.action(ActionCode.COMMIT, null);
}
if (lastActiveFilter == -1) {
return outputStreamOutputBuffer.doWrite(chunk);
} else {
return activeFilters[lastActiveFilter].doWrite(chunk);
}
}
@Override
public long getBytesWritten() {
if (lastActiveFilter == -1) {
return outputStreamOutputBuffer.getBytesWritten();
} else {
return activeFilters[lastActiveFilter].getBytesWritten();
}
}
// ----------------------------------------------- HttpOutputBuffer Methods
/**
* Flush the response.
*
* @throws IOException an underlying I/O error occurred
*/
@Override
public void flush() throws IOException {
if (lastActiveFilter == -1) {
outputStreamOutputBuffer.flush();
} else {
activeFilters[lastActiveFilter].flush();
}
}
@Override
public void end() throws IOException {
if (responseFinished) {
return;
}
if (lastActiveFilter == -1) {
outputStreamOutputBuffer.end();
} else {
activeFilters[lastActiveFilter].end();
}
responseFinished = true;
}
// --------------------------------------------------------- Public Methods
/**
* Reset the header buffer if an error occurs during the writing of the headers so the error response can be
* written.
*/
void resetHeaderBuffer() {
headerBuffer.position(0).limit(headerBuffer.capacity());
}
/**
* Recycle the output buffer. This should be called when closing the connection.
*/
public void recycle() {
nextRequest();
socketWrapper = null;
}
/**
* End processing of current HTTP request. Note: All bytes of the current request should have been already consumed.
* This method only resets all the pointers so that we are ready to parse the next HTTP request.
*/
public void nextRequest() {
// Recycle filters
for (int i = 0; i <= lastActiveFilter; i++) {
activeFilters[i].recycle();
}
// Recycle response object
response.recycle();
// Reset pointers
headerBuffer.position(0).limit(headerBuffer.capacity());
lastActiveFilter = -1;
ackSent = false;
responseFinished = false;
byteCount = 0;
}
public void init(SocketWrapperBase<?> socketWrapper) {
this.socketWrapper = socketWrapper;
}
public void sendAck() throws IOException {
// It possible that the protocol configuration is changed between the
// request being received and the first read of the body. That could led
// to multiple calls to this method so ensure the ACK is only sent once.
if (!response.isCommitted() && !ackSent) {
ackSent = true;
socketWrapper.write(isBlocking(), Constants.ACK_BYTES, 0, Constants.ACK_BYTES.length);
if (flushBuffer(true)) {
throw new IOException(sm.getString("iob.failedwrite.ack"));
}
}
}
/**
* Commit the response.
*
* @throws IOException an underlying I/O error occurred
*/
protected void commit() throws IOException {
response.setCommitted(true);
if (headerBuffer.position() > 0) {
// Sending the response header buffer
headerBuffer.flip();
try {
SocketWrapperBase<?> socketWrapper = this.socketWrapper;
if (socketWrapper != null) {
socketWrapper.write(isBlocking(), headerBuffer);
} else {
throw new CloseNowException(sm.getString("iob.failedwrite"));
}
} finally {
headerBuffer.position(0).limit(headerBuffer.capacity());
}
}
}
/**
* Send the response status line.
*/
public void sendStatus() {
// Write protocol name
write(Constants.HTTP_11_BYTES);
headerBuffer.put(Constants.SP);
// Write status code
int status = response.getStatus();
switch (status) {
case 200:
write(Constants._200_BYTES);
break;
case 400:
write(Constants._400_BYTES);
break;
case 404:
write(Constants._404_BYTES);
break;
default:
write(status);
}
headerBuffer.put(Constants.SP);
// The reason phrase is optional but the space before it is not. Skip
// sending the reason phrase. Clients should ignore it (RFC 7230) and it
// just wastes bytes.
headerBuffer.put(Constants.CR).put(Constants.LF);
}
/**
* Send a header.
*
* @param name Header name
* @param value Header value
*/
public void sendHeader(MessageBytes name, MessageBytes value) {
write(name);
headerBuffer.put(Constants.COLON).put(Constants.SP);
write(value);
headerBuffer.put(Constants.CR).put(Constants.LF);
}
/**
* End the header block.
*/
public void endHeaders() {
headerBuffer.put(Constants.CR).put(Constants.LF);
}
/**
* This method will write the contents of the specified message bytes buffer to the output stream, without
* filtering. This method is meant to be used to write the response header.
*
* @param mb data to be written
*/
private void write(MessageBytes mb) {
if (mb.getType() != MessageBytes.T_BYTES) {
mb.toBytes();
ByteChunk bc = mb.getByteChunk();
// Need to filter out CTLs excluding TAB. ISO-8859-1 and UTF-8
// values will be OK. Strings using other encodings may be
// corrupted.
byte[] buffer = bc.getBuffer();
for (int i = bc.getOffset(); i < bc.getLength(); i++) {
// byte values are signed i.e. -128 to 127
// The values are used unsigned. 0 to 31 are CTLs so they are
// filtered (apart from TAB which is 9). 127 is a control (DEL).
// The values 128 to 255 are all OK. Converting those to signed
// gives -128 to -1.
if ((buffer[i] > -1 && buffer[i] <= 31 && buffer[i] != 9) || buffer[i] == 127) {
buffer[i] = ' ';
}
}
}
write(mb.getByteChunk());
}
/**
* This method will write the contents of the specified byte chunk to the output stream, without filtering. This
* method is meant to be used to write the response header.
*
* @param bc data to be written
*/
private void write(ByteChunk bc) {
// Writing the byte chunk to the output buffer
int length = bc.getLength();
checkLengthBeforeWrite(length);
headerBuffer.put(bc.getBytes(), bc.getStart(), length);
}
/**
* This method will write the contents of the specified byte buffer to the output stream, without filtering. This
* method is meant to be used to write the response header.
*
* @param b data to be written
*/
public void write(byte[] b) {
checkLengthBeforeWrite(b.length);
// Writing the byte chunk to the output buffer
headerBuffer.put(b);
}
/**
* This method will write the specified integer to the output stream. This method is meant to be used to write the
* response header.
*
* @param value data to be written
*/
private void write(int value) {
// From the Tomcat 3.3 HTTP/1.0 connector
String s = Integer.toString(value);
int len = s.length();
checkLengthBeforeWrite(len);
for (int i = 0; i < len; i++) {
char c = s.charAt(i);
headerBuffer.put((byte) c);
}
}
/**
* Checks to see if there is enough space in the buffer to write the requested number of bytes.
*/
private void checkLengthBeforeWrite(int length) {
// "+ 4": BZ 57509. Reserve space for CR/LF/COLON/SP characters that
// are put directly into the buffer following this write operation.
if (headerBuffer.position() + length + 4 > headerBuffer.capacity()) {
throw new HeadersTooLargeException(sm.getString("iob.responseheadertoolarge.error"));
}
}
// ------------------------------------------------------ Non-blocking writes
/**
* Writes any remaining buffered data.
*
* @param block Should this method block until the buffer is empty
*
* @return <code>true</code> if data remains in the buffer (which can only happen in non-blocking mode) else
* <code>false</code>.
*
* @throws IOException Error writing data
*/
protected boolean flushBuffer(boolean block) throws IOException {
return socketWrapper.flush(block);
}
/**
* Is standard Servlet blocking IO being used for output?
*
* @return <code>true</code> if this is blocking IO
*/
protected final boolean isBlocking() {
return response.getWriteListener() == null;
}
protected final boolean isReady() {
boolean result = !hasDataToWrite();
if (!result) {
socketWrapper.registerWriteInterest();
}
return result;
}
public boolean hasDataToWrite() {
return socketWrapper.hasDataToWrite();
}
public void registerWriteInterest() {
socketWrapper.registerWriteInterest();
}
boolean isChunking() {
for (int i = 0; i < lastActiveFilter; i++) {
if (activeFilters[i] == filterLibrary[Constants.CHUNKED_FILTER]) {
return true;
}
}
return false;
}
// ------------------------------------------ SocketOutputBuffer Inner Class
/**
* This class is an output buffer which will write data to a socket.
*/
protected class SocketOutputBuffer implements HttpOutputBuffer {
/**
* Write chunk.
*/
@Override
public int doWrite(ByteBuffer chunk) throws IOException {
try {
int len = chunk.remaining();
SocketWrapperBase<?> socketWrapper = Http11OutputBuffer.this.socketWrapper;
if (socketWrapper != null) {
socketWrapper.write(isBlocking(), chunk);
} else {
throw new CloseNowException(sm.getString("iob.failedwrite"));
}
len -= chunk.remaining();
byteCount += len;
return len;
} catch (IOException ioe) {
response.action(ActionCode.CLOSE_NOW, ioe);
// Re-throw
throw ioe;
}
}
@Override
public long getBytesWritten() {
return byteCount;
}
@Override
public void end() throws IOException {
socketWrapper.flush(true);
}
@Override
public void flush() throws IOException {
socketWrapper.flush(isBlocking());
}
}
}