ExtensionFunction (Undertow 2.1.0.Final API)

All Known Implementing Classes:

CompositeExtensionFunction, NoopExtensionFunction, PerMessageDeflateFunction
```
public interface ExtensionFunction
```
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

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`RSV1` Bitmask for RSV1 bit used in extensions.
`static int`	`RSV2` Bitmask for RSV2 bit used in extensions.
`static int`	`RSV3` Bitmask for RSV3 bit used in extensions.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`dispose()` Dispose this function.
`boolean`	`hasExtensionOpCode()` Validate if current extension defines a new WebSocket Opcode.
`PooledByteBuffer`	`transformForRead(PooledByteBuffer pooledBuffer, StreamSourceFrameChannel channel, boolean lastFragmentOfMessage)` Transform the supplied buffer per this extension.
`PooledByteBuffer`	`transformForWrite(PooledByteBuffer pooledBuffer, StreamSinkFrameChannel channel, boolean lastFrame)` Transform the supplied buffer per this extension.
`int`	`writeRsv(int rsv)` Add RSV bits (RSV1, RSV2, RSV3) to the current rsv status.

- Field Detail
  - RSV1
```
static final int RSV1
```
    Bitmask for RSV1 bit used in extensions.
    
    See Also:
    
    Constant Field Values
  - RSV2
```
static final int RSV2
```
    Bitmask for RSV2 bit used in extensions.
    
    See Also:
    
    Constant Field Values
  - RSV3
```
static final int RSV3
```
    Bitmask for RSV3 bit used in extensions.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - hasExtensionOpCode
```
boolean hasExtensionOpCode()
```
    Validate if current extension defines a new WebSocket Opcode.
    
    Returns:
    
    true if current extension defines specific Opcode false is current extension does not define specific Opcode
    
    See Also:
    
    WebSocket Base Framing Protocol Reference
  - writeRsv
```
int writeRsv(int rsv)
```
    Add RSV bits (RSV1, RSV2, RSV3) to the current rsv status.
    
    Parameters:
    
    rsv - current RSV bits status
    
    Returns:
    
    rsv status
  - transformForWrite
```
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
    
    Parameters:
    
    pooledBuffer - Buffer to transform
    
    channel - working channel
    
    Returns:
    
    transformed buffer (may be the same one, just with modified contents)
    
    Throws:
    
    IOException
  - transformForRead
```
PooledByteBuffer transformForRead(PooledByteBuffer pooledBuffer,
                                  StreamSourceFrameChannel channel,
                                  boolean lastFragmentOfMessage)
                           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
    
    Parameters:
    
    pooledBuffer - Buffer to transform
    
    channel - working channel
    
    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
    
    Returns:
    
    transformed buffer (may be the same one, just with modified contents)
    
    Throws:
    
    IOException
  - dispose
```
void dispose()
```
    Dispose this function. Called upon connection closure

Interface ExtensionFunction

Field Summary

Method Summary

Field Detail

RSV1

RSV2

RSV3

Method Detail

hasExtensionOpCode

writeRsv

transformForWrite

transformForRead

dispose