org.apache.catalina.websocket.WsInputStream Maven / Gradle / Ivy
/*
* 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.catalina.websocket;
import java.io.IOException;
import java.io.InputStream;
import org.apache.coyote.http11.upgrade.UpgradeProcessor;
import org.apache.tomcat.util.res.StringManager;
/**
* This class is used to read WebSocket frames from the underlying socket and
* makes the payload available for reading as an {@link InputStream}. It only
* makes the number of bytes declared in the payload length available for
* reading even if more bytes are available from the socket.
*/
public class WsInputStream extends InputStream {
private static final StringManager sm =
StringManager.getManager(Constants.Package);
private final UpgradeProcessor processor;
private final WsOutbound outbound;
private WsFrame frame;
private long remaining;
private long readThisFragment;
private String error = null;
public WsInputStream(UpgradeProcessor processor, WsOutbound outbound) {
this.processor = processor;
this.outbound = outbound;
}
/**
* Process the next WebSocket frame.
*
* @param block Should this method block until a frame is presented if no
* data is currently available to process. Note that if a
* single byte is available, this method will block until the
* complete frame (excluding payload for non-control frames) is
* available.
*
* @return The next frame to be processed or null if block is
* false and there is no data to be processed.
*
* @throws IOException If a problem occurs reading the data for the frame.
*/
public WsFrame nextFrame(boolean block) throws IOException {
frame = WsFrame.nextFrame(processor, block);
if (frame != null) {
readThisFragment = 0;
remaining = frame.getPayLoadLength();
}
return frame;
}
// ----------------------------------------------------- InputStream methods
@Override
public int read() throws IOException {
makePayloadDataAvailable();
if (remaining == 0) {
return -1;
}
remaining--;
readThisFragment++;
int masked = processor.read();
if(masked == -1) {
return -1;
}
return masked ^
(frame.getMask()[(int) ((readThisFragment - 1) % 4)] & 0xFF);
}
@Override
public int read(byte b[], int off, int len) throws IOException {
makePayloadDataAvailable();
if (remaining == 0) {
return -1;
}
if (len > remaining) {
len = (int) remaining;
}
int result = processor.read(true, b, off, len);
if(result == -1) {
return -1;
}
for (int i = off; i < off + result; i++) {
b[i] = (byte) (b[i] ^
frame.getMask()[(int) ((readThisFragment + i - off) % 4)]);
}
remaining -= result;
readThisFragment += result;
return result;
}
/*
* Ensures that there is payload data ready to read.
*/
private void makePayloadDataAvailable() throws IOException {
if (error != null) {
throw new IOException(error);
}
while (remaining == 0 && !frame.getFin()) {
// Need more data - process next frame
nextFrame(true);
while (frame.isControl()) {
if (frame.getOpCode() == Constants.OPCODE_PING) {
outbound.pong(frame.getPayLoad());
} else if (frame.getOpCode() == Constants.OPCODE_PONG) {
// NO-OP. Swallow it.
} else if (frame.getOpCode() == Constants.OPCODE_CLOSE) {
outbound.close(frame);
} else{
throw new IOException(sm.getString("is.unknownOpCode",
Byte.valueOf(frame.getOpCode())));
}
nextFrame(true);
}
if (frame.getOpCode() != Constants.OPCODE_CONTINUATION) {
error = sm.getString("is.notContinuation",
Byte.valueOf(frame.getOpCode()));
throw new IOException(error);
}
}
}
}