Class PerMessageDeflateExtension

java.lang.Object
org.java_websocket.extensions.DefaultExtension
org.java_websocket.extensions.CompressionExtension
org.java_websocket.extensions.permessage_deflate.PerMessageDeflateExtension
All Implemented Interfaces:
IExtension
public class PerMessageDeflateExtension extends CompressionExtension
PerMessage Deflate Extension (7. The "permessage-deflate" Extension in RFC 7692).
See Also:

  • Field Details

    • EXTENSION_REGISTERED_NAME

      private static final String EXTENSION_REGISTERED_NAME
      See Also:

    • SERVER_NO_CONTEXT_TAKEOVER

      private static final String SERVER_NO_CONTEXT_TAKEOVER
      See Also:

    • CLIENT_NO_CONTEXT_TAKEOVER

      private static final String CLIENT_NO_CONTEXT_TAKEOVER
      See Also:

    • SERVER_MAX_WINDOW_BITS

      private static final String SERVER_MAX_WINDOW_BITS
      See Also:

    • CLIENT_MAX_WINDOW_BITS

      private static final String CLIENT_MAX_WINDOW_BITS
      See Also:

    • serverMaxWindowBits

      private static final int serverMaxWindowBits
      See Also:

    • clientMaxWindowBits

      private static final int clientMaxWindowBits
      See Also:

    • TAIL_BYTES

      private static final byte[] TAIL_BYTES

    • BUFFER_SIZE

      private static final int BUFFER_SIZE
      See Also:

    • threshold

      private int threshold

    • serverNoContextTakeover

      private boolean serverNoContextTakeover

    • clientNoContextTakeover

      private boolean clientNoContextTakeover

    • requestedParameters

      private Map<String,String> requestedParameters

    • compressionLevel

      private final int compressionLevel

    • inflater

      private final Inflater inflater

    • deflater

      private final Deflater deflater

  • Constructor Details

  • Method Details

    • getCompressionLevel

      public int getCompressionLevel()
      Get the compression level used for the compressor.
      Returns:
      the compression level

    • getThreshold

      public int getThreshold()
      Get the size threshold for doing the compression
      Returns:
      Size (in bytes) below which messages will not be compressed
      Since:
      1.5.3

    • setThreshold

      public void setThreshold(int threshold)
      Set the size when payloads smaller than this will not be compressed.
      Parameters:
      threshold - the size in bytes
      Since:
      1.5.3

    • isServerNoContextTakeover

      public boolean isServerNoContextTakeover()
      Access the "server_no_context_takeover" extension parameter
      Returns:
      serverNoContextTakeover is the server no context parameter active
      See Also:

    • setServerNoContextTakeover

      public void setServerNoContextTakeover(boolean serverNoContextTakeover)
      Setter for the "server_no_context_takeover" extension parameter
      Parameters:
      serverNoContextTakeover - set the server no context parameter
      See Also:

    • isClientNoContextTakeover

      public boolean isClientNoContextTakeover()
      Access the "client_no_context_takeover" extension parameter
      Returns:
      clientNoContextTakeover is the client no context parameter active
      See Also:

    • setClientNoContextTakeover

      public void setClientNoContextTakeover(boolean clientNoContextTakeover)
      Setter for the "client_no_context_takeover" extension parameter
      Parameters:
      clientNoContextTakeover - set the client no context parameter
      See Also:

    • decodeFrame

      public void decodeFrame(Framedata inputFrame) throws InvalidDataException
      Description copied from interface: IExtension
      Decode a frame with a extension specific algorithm. The algorithm is subject to be implemented by the specific extension. The resulting frame will be used in the application
      Specified by:
      decodeFrame in interface IExtension
      Overrides:
      decodeFrame in class DefaultExtension
      Parameters:
      inputFrame - the frame, which has do be decoded to be used in the application
      Throws:
      InvalidDataException - Throw InvalidDataException if the received frame is not correctly implemented by the other endpoint or there are other protocol errors/decoding errors

    • decompress

      private void decompress(byte[] data, ByteArrayOutputStream outputBuffer) throws DataFormatException
      Parameters:
      data - the bytes of data
      outputBuffer - the output stream
      Throws:
      DataFormatException

    • encodeFrame

      public void encodeFrame(Framedata inputFrame)
      Description copied from interface: IExtension
      Encode a frame with a extension specific algorithm. The algorithm is subject to be implemented by the specific extension. The resulting frame will be send to the other endpoint.
      Specified by:
      encodeFrame in interface IExtension
      Overrides:
      encodeFrame in class DefaultExtension
      Parameters:
      inputFrame - the frame, which has do be encoded to be used on the other endpoint

    • endsWithTail

      private static boolean endsWithTail(byte[] data)
      Parameters:
      data - the bytes of data
      Returns:
      true if the data is OK

    • acceptProvidedExtensionAsServer

      public boolean acceptProvidedExtensionAsServer(String inputExtension)
      Description copied from interface: IExtension
      Check if the received Sec-WebSocket-Extensions header field contains a offer for the specific extension if the endpoint is in the role of a server
      Specified by:
      acceptProvidedExtensionAsServer in interface IExtension
      Overrides:
      acceptProvidedExtensionAsServer in class DefaultExtension
      Parameters:
      inputExtension - the received Sec-WebSocket-Extensions header field offered by the other endpoint
      Returns:
      true, if the offer does fit to this specific extension

    • acceptProvidedExtensionAsClient

      public boolean acceptProvidedExtensionAsClient(String inputExtension)
      Description copied from interface: IExtension
      Check if the received Sec-WebSocket-Extensions header field contains a offer for the specific extension if the endpoint is in the role of a client
      Specified by:
      acceptProvidedExtensionAsClient in interface IExtension
      Overrides:
      acceptProvidedExtensionAsClient in class DefaultExtension
      Parameters:
      inputExtension - the received Sec-WebSocket-Extensions header field offered by the other endpoint
      Returns:
      true, if the offer does fit to this specific extension

    • getProvidedExtensionAsClient

      public String getProvidedExtensionAsClient()
      Description copied from interface: IExtension
      Return the specific Sec-WebSocket-Extensions header offer for this extension if the endpoint is in the role of a client. If the extension returns an empty string (""), the offer will not be included in the handshake.
      Specified by:
      getProvidedExtensionAsClient in interface IExtension
      Overrides:
      getProvidedExtensionAsClient in class DefaultExtension
      Returns:
      the specific Sec-WebSocket-Extensions header for this extension

    • getProvidedExtensionAsServer

      public String getProvidedExtensionAsServer()
      Description copied from interface: IExtension
      Return the specific Sec-WebSocket-Extensions header offer for this extension if the endpoint is in the role of a server. If the extension returns an empty string (""), the offer will not be included in the handshake.
      Specified by:
      getProvidedExtensionAsServer in interface IExtension
      Overrides:
      getProvidedExtensionAsServer in class DefaultExtension
      Returns:
      the specific Sec-WebSocket-Extensions header for this extension

    • copyInstance

      public IExtension copyInstance()
      Description copied from interface: IExtension
      Extensions must only be by one websocket at all. To prevent extensions to be used more than once the Websocket implementation should call this method in order to create a new usable version of a given extension instance.
      The copy can be safely used in conjunction with a new websocket connection.
      Specified by:
      copyInstance in interface IExtension
      Overrides:
      copyInstance in class DefaultExtension
      Returns:
      a copy of the extension

    • isFrameValid

      public void isFrameValid(Framedata inputFrame) throws InvalidDataException
      This extension requires the RSV1 bit to be set only for the first frame. If the frame is type is CONTINUOUS, RSV1 bit must be unset.
      Specified by:
      isFrameValid in interface IExtension
      Overrides:
      isFrameValid in class CompressionExtension
      Parameters:
      inputFrame - the received frame
      Throws:
      InvalidDataException - Throw InvalidDataException if the received frame is not correctly implementing the specification for the specific extension

    • toString

      public String toString()
      Description copied from interface: IExtension
      Return a string which should contain the class name as well as additional information about the current configurations for this extension (DEBUG purposes)
      Specified by:
      toString in interface IExtension
      Overrides:
      toString in class DefaultExtension
      Returns:
      a string containing the class name as well as additional information