Class PerMessageDeflateServerExtensionHandshaker

java.lang.Object

io.netty.handler.codec.http.websocketx.extensions.compression.PerMessageDeflateServerExtensionHandshaker

All Implemented Interfaces:

WebSocketServerExtensionHandshaker

public final class PerMessageDeflateServerExtensionHandshaker
extends Object
implements WebSocketServerExtensionHandshaker

permessage-deflate handshake implementation.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_MEM_LEVEL	Default memory level used for deflate compression (zlib MAX_MEM_LEVEL).
static final int	MAX_MEM_LEVEL
static final int	MAX_WINDOW_SIZE
static final int	MIN_MEM_LEVEL
static final int	MIN_WINDOW_SIZE

Constructor Summary

Constructors

Constructor	Description
PerMessageDeflateServerExtensionHandshaker()	Deprecated. Use invalid @link {@link PerMessageDeflateServerExtensionHandshaker# PerMessageDeflateServerExtensionHandshaker(int)}.
PerMessageDeflateServerExtensionHandshaker(int maxAllocation)	Constructor with default configuration.
PerMessageDeflateServerExtensionHandshaker(int compressionLevel, boolean allowServerWindowSize, int preferredClientWindowSize, boolean allowServerNoContext, boolean preferredClientNoContext)	Deprecated. Use PerMessageDeflateServerExtensionHandshaker(int, boolean, int, boolean, boolean, int).
PerMessageDeflateServerExtensionHandshaker(int compressionLevel, boolean allowServerWindowSize, int preferredClientWindowSize, boolean allowServerNoContext, boolean preferredClientNoContext, int maxAllocation)	Constructor with custom configuration.
PerMessageDeflateServerExtensionHandshaker(int compressionLevel, boolean allowServerWindowSize, int preferredClientWindowSize, boolean allowServerNoContext, boolean preferredClientNoContext, int serverWindowSize, int memLevel, int maxAllocation)	Constructor with custom configuration including server-side compressor memory limits.
PerMessageDeflateServerExtensionHandshaker(int compressionLevel, boolean allowServerWindowSize, int preferredClientWindowSize, boolean allowServerNoContext, boolean preferredClientNoContext, int serverWindowSize, int memLevel, WebSocketExtensionFilterProvider extensionFilterProvider, int maxAllocation)	Constructor with full custom configuration.
PerMessageDeflateServerExtensionHandshaker(int compressionLevel, boolean allowServerWindowSize, int preferredClientWindowSize, boolean allowServerNoContext, boolean preferredClientNoContext, WebSocketExtensionFilterProvider extensionFilterProvider)	Deprecated. Use PerMessageDeflateServerExtensionHandshaker(int, boolean, int, boolean, boolean, WebSocketExtensionFilterProvider, int).
PerMessageDeflateServerExtensionHandshaker(int compressionLevel, boolean allowServerWindowSize, int preferredClientWindowSize, boolean allowServerNoContext, boolean preferredClientNoContext, WebSocketExtensionFilterProvider extensionFilterProvider, int maxAllocation)	Deprecated. Use PerMessageDeflateServerExtensionHandshaker(int, boolean, int, boolean, boolean, int, int, WebSocketExtensionFilterProvider, int).

Method Summary

Modifier and Type	Method	Description
WebSocketServerExtension	handshakeExtension(WebSocketExtensionData extensionData)	Handshake based on client request.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

MIN_WINDOW_SIZE

public static final int MIN_WINDOW_SIZE

See Also:

• Constant Field Values

MAX_WINDOW_SIZE

public static final int MAX_WINDOW_SIZE

See Also:

• Constant Field Values

DEFAULT_MEM_LEVEL

public static final int DEFAULT_MEM_LEVEL

Default memory level used for deflate compression (zlib MAX_MEM_LEVEL).

See Also:

• Constant Field Values

MIN_MEM_LEVEL

public static final int MIN_MEM_LEVEL

See Also:

• Constant Field Values

MAX_MEM_LEVEL

public static final int MAX_MEM_LEVEL

See Also:

• Constant Field Values

Constructor Details

PerMessageDeflateServerExtensionHandshaker

@Deprecated
public PerMessageDeflateServerExtensionHandshaker()

Deprecated.

Use

invalid @link

{@link PerMessageDeflateServerExtensionHandshaker#

PerMessageDeflateServerExtensionHandshaker(int)}.

Constructor with default configuration.

PerMessageDeflateServerExtensionHandshaker

public PerMessageDeflateServerExtensionHandshaker(int maxAllocation)

Constructor with default configuration.

Parameters:

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.

PerMessageDeflateServerExtensionHandshaker

@Deprecated
public PerMessageDeflateServerExtensionHandshaker(int compressionLevel,
 boolean allowServerWindowSize,
 int preferredClientWindowSize,
 boolean allowServerNoContext,
 boolean preferredClientNoContext)

Deprecated.

Use PerMessageDeflateServerExtensionHandshaker(int, boolean, int, boolean, boolean, int).

Constructor with custom configuration.

Parameters:

compressionLevel - Compression level between 0 and 9 (default is 6).

allowServerWindowSize - allows WebSocket client to customize the server inflater window size (default is false).

preferredClientWindowSize - indicates the preferred client window size to use if client inflater is customizable.

allowServerNoContext - allows WebSocket client to activate server_no_context_takeover (default is false).

preferredClientNoContext - indicates if server prefers to activate client_no_context_takeover if client is compatible with (default is false).

PerMessageDeflateServerExtensionHandshaker

public PerMessageDeflateServerExtensionHandshaker(int compressionLevel,
 boolean allowServerWindowSize,
 int preferredClientWindowSize,
 boolean allowServerNoContext,
 boolean preferredClientNoContext,
 int maxAllocation)

Constructor with custom configuration.

Parameters:

compressionLevel - Compression level between 0 and 9 (default is 6).

allowServerWindowSize - allows WebSocket client to customize the server inflater window size (default is false).

preferredClientWindowSize - indicates the preferred client window size to use if client inflater is customizable.

allowServerNoContext - allows WebSocket client to activate server_no_context_takeover (default is false).

preferredClientNoContext - indicates if server prefers to activate client_no_context_takeover if client is compatible with (default is false).

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.

PerMessageDeflateServerExtensionHandshaker

public PerMessageDeflateServerExtensionHandshaker(int compressionLevel,
 boolean allowServerWindowSize,
 int preferredClientWindowSize,
 boolean allowServerNoContext,
 boolean preferredClientNoContext,
 int serverWindowSize,
 int memLevel,
 int maxAllocation)

Constructor with custom configuration including server-side compressor memory limits.

Parameters:

compressionLevel - Compression level between 0 and 9 (default is 6).

allowServerWindowSize - allows WebSocket client to customize the server inflater window size (default is false).

preferredClientWindowSize - indicates the preferred client window size to use if client inflater is customizable.

allowServerNoContext - allows WebSocket client to activate server_no_context_takeover (default is false).

preferredClientNoContext - indicates if server prefers to activate client_no_context_takeover if client is compatible with (default is false).

serverWindowSize - upper bound (in bits, 8-15) on the server-side deflate window. If the client offers server_max_window_bits=N, the negotiated value is min(N, serverWindowSize). Set lower than MAX_WINDOW_SIZE to reduce per-connection memory.

memLevel - zlib memory level for the server-side deflater (1-9). Lower values reduce per-connection memory at the cost of compression ratio.

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.

PerMessageDeflateServerExtensionHandshaker

@Deprecated
public PerMessageDeflateServerExtensionHandshaker(int compressionLevel,
 boolean allowServerWindowSize,
 int preferredClientWindowSize,
 boolean allowServerNoContext,
 boolean preferredClientNoContext,
 WebSocketExtensionFilterProvider extensionFilterProvider)

Deprecated.

Use PerMessageDeflateServerExtensionHandshaker(int, boolean, int, boolean, boolean, WebSocketExtensionFilterProvider, int).

Constructor with custom configuration.

Parameters:

compressionLevel - Compression level between 0 and 9 (default is 6).

allowServerWindowSize - allows WebSocket client to customize the server inflater window size (default is false).

preferredClientWindowSize - indicates the preferred client window size to use if client inflater is customizable.

allowServerNoContext - allows WebSocket client to activate server_no_context_takeover (default is false).

preferredClientNoContext - indicates if server prefers to activate client_no_context_takeover if client is compatible with (default is false).

extensionFilterProvider - provides server extension filters for per message deflate encoder and decoder.

PerMessageDeflateServerExtensionHandshaker

@Deprecated
public PerMessageDeflateServerExtensionHandshaker(int compressionLevel,
 boolean allowServerWindowSize,
 int preferredClientWindowSize,
 boolean allowServerNoContext,
 boolean preferredClientNoContext,
 WebSocketExtensionFilterProvider extensionFilterProvider,
 int maxAllocation)

Deprecated.

Use PerMessageDeflateServerExtensionHandshaker(int, boolean, int, boolean, boolean, int, int, WebSocketExtensionFilterProvider, int).

Constructor with custom configuration.

Parameters:

compressionLevel - Compression level between 0 and 9 (default is 6).

allowServerWindowSize - allows WebSocket client to customize the server inflater window size (default is false).

preferredClientWindowSize - indicates the preferred client window size to use if client inflater is customizable.

allowServerNoContext - allows WebSocket client to activate server_no_context_takeover (default is false).

preferredClientNoContext - indicates if server prefers to activate client_no_context_takeover if client is compatible with (default is false).

extensionFilterProvider - provides server extension filters for per message deflate encoder and decoder.

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.

PerMessageDeflateServerExtensionHandshaker

public PerMessageDeflateServerExtensionHandshaker(int compressionLevel,
 boolean allowServerWindowSize,
 int preferredClientWindowSize,
 boolean allowServerNoContext,
 boolean preferredClientNoContext,
 int serverWindowSize,
 int memLevel,
 WebSocketExtensionFilterProvider extensionFilterProvider,
 int maxAllocation)

Constructor with full custom configuration.

Parameters:

compressionLevel - Compression level between 0 and 9 (default is 6).

allowServerWindowSize - allows WebSocket client to customize the server inflater window size (default is false).

preferredClientWindowSize - indicates the preferred client window size to use if client inflater is customizable.

allowServerNoContext - allows WebSocket client to activate server_no_context_takeover (default is false).

preferredClientNoContext - indicates if server prefers to activate client_no_context_takeover if client is compatible with (default is false).

serverWindowSize - upper bound (in bits, 8-15) on the server-side deflate window. If the client offers server_max_window_bits=N, the negotiated value is min(N, serverWindowSize). Per RFC 7692 §7.1.2.1 the server may include server_max_window_bits with the same or smaller value than the offer; this handshaker also advertises it unilaterally when serverWindowSize is less than MAX_WINDOW_SIZE.

memLevel - zlib memory level for the server-side deflater (1-9). Lower values reduce per-connection memory at the cost of compression ratio.

extensionFilterProvider - provides server extension filters for per message deflate encoder and decoder.

maxAllocation - Maximum size of the decompression buffer. Must be >= 0. If zero, maximum size is not limited.

Method Details

handshakeExtension

public WebSocketServerExtension handshakeExtension(WebSocketExtensionData extensionData)

Description copied from interface: WebSocketServerExtensionHandshaker

Handshake based on client request. It must failed with null if server cannot handle it.

Specified by:

handshakeExtension in interface WebSocketServerExtensionHandshaker

Parameters:

extensionData - the extension configuration sent by the client.

Returns:

an initialized extension if handshake phase succeed or null if failed.