io.undertow.websockets.extensions.ExtensionFunction Maven / Gradle / Ivy
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* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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
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package io.undertow.websockets.extensions;
import io.undertow.connector.PooledByteBuffer;
import io.undertow.websockets.core.StreamSinkFrameChannel;
import io.undertow.websockets.core.StreamSourceFrameChannel;
import java.io.IOException;
/**
* Base interface for WebSocket Extensions implementation.
*
* It interacts at the connection phase. It is responsible to apply extension's logic before to write and after to read to/from
* a WebSocket Endpoint.
*
* Several extensions can be present in a WebSocket Endpoint being executed in a chain pattern.
*
* Extension state is stored per WebSocket connection.
*
* @author Lucas Ponce
*/
public interface ExtensionFunction {
/**
* Bitmask for RSV1 bit used in extensions.
*/
int RSV1 = 0x04;
/**
* Bitmask for RSV2 bit used in extensions.
*/
int RSV2 = 0x02;
/**
* Bitmask for RSV3 bit used in extensions.
*/
int RSV3 = 0x01;
/**
* Validate if current extension defines a new WebSocket Opcode.
*
* @return {@code true} if current extension defines specific Opcode
* {@code false} is current extension does not define specific Opcode
* @see WebSocket Base Framing Protocol Reference
*/
boolean hasExtensionOpCode();
/**
* Add RSV bits (RSV1, RSV2, RSV3) to the current rsv status.
*
* @param rsv current RSV bits status
* @return rsv status
*/
int writeRsv(int rsv);
/**
* Transform the supplied buffer per this extension. The buffer can be modified in place, or a new pooled buffer
* can be returned (in which case be sure to free the original buffer
*
* @param pooledBuffer Buffer to transform
* @param channel working channel
* @return transformed buffer (may be the same one, just with modified contents)
* @throws IOException
*/
PooledByteBuffer transformForWrite(PooledByteBuffer pooledBuffer, StreamSinkFrameChannel channel, boolean lastFrame) throws IOException;
/**
* Transform the supplied buffer per this extension. The buffer can be modified in place, or a new pooled buffer
* can be returned (in which case be sure to free the original buffer
*
* @param pooledBuffer Buffer to transform
* @param channel working channel
* @param lastFragmentOfMessage If this frame is the last fragment of a message. Note that this may not be received for every message, if the message ends with an empty frame
* @return transformed buffer (may be the same one, just with modified contents)
* @throws IOException
*/
PooledByteBuffer transformForRead(PooledByteBuffer pooledBuffer, StreamSourceFrameChannel channel, boolean lastFragmentOfMessage) throws IOException;
/**
* Dispose this function. Called upon connection closure
*/
void dispose();
}