Class DelegatingDecompressorFrameListener

java.lang.Object

io.netty.handler.codec.http2.Http2FrameListenerDecorator

io.netty.handler.codec.http2.DelegatingDecompressorFrameListener

All Implemented Interfaces:

Http2FrameListener

public class DelegatingDecompressorFrameListener
extends Http2FrameListenerDecorator

An HTTP2 frame listener that will decompress data frames according to the content-encoding header for each stream. The decompression provided by this class will be applied to the data for the entire stream.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private final class	DelegatingDecompressorFrameListener.ConsumedBytesConverter	A decorator around the local flow controller that converts consumed bytes from uncompressed to compressed.
private static final class	DelegatingDecompressorFrameListener.Http2Decompressor	Provides the state for stream DATA frame decompression.

Field Summary

Fields

Modifier and Type	Field	Description
private final Http2Connection	connection
private boolean	flowControllerInitialized
private final int	maxAllocation
private final Http2Connection.PropertyKey	propertyKey
private final boolean	strict

Fields inherited from class Http2FrameListenerDecorator

listener

Constructor Summary

Constructors

Constructor	Description
DelegatingDecompressorFrameListener(Http2Connection connection, Http2FrameListener listener)	Deprecated. Use DelegatingDecompressorFrameListener(Http2Connection, Http2FrameListener, int)
DelegatingDecompressorFrameListener(Http2Connection connection, Http2FrameListener listener, boolean strict)	Deprecated. Use DelegatingDecompressorFrameListener(Http2Connection, Http2FrameListener, boolean, int)
DelegatingDecompressorFrameListener(Http2Connection connection, Http2FrameListener listener, boolean strict, int maxAllocation)	Create a new instance.
DelegatingDecompressorFrameListener(Http2Connection connection, Http2FrameListener listener, int maxAllocation)	Create a new instance.

Method Summary

Modifier and Type	Method	Description
(package private) DelegatingDecompressorFrameListener.Http2Decompressor	decompressor(Http2Stream stream)
protected CharSequence	getTargetContentEncoding(CharSequence contentEncoding)	Returns the expected content encoding of the decoded content.
private void	initDecompressor(ChannelHandlerContext ctx, int streamId, Http2Headers headers, boolean endOfStream)	Checks if a new decompressor object is needed for the stream identified by streamId.
protected EmbeddedChannel	newContentDecompressor(ChannelHandlerContext ctx, CharSequence contentEncoding)	Returns a new EmbeddedChannel that decodes the HTTP2 message content encoded in the specified contentEncoding.
int	onDataRead(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding, boolean endOfStream)	Handles an inbound DATA frame.
void	onHeadersRead(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int padding, boolean endStream)	Handles an inbound HEADERS frame.
void	onHeadersRead(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int streamDependency, short weight, boolean exclusive, int padding, boolean endStream)	Handles an inbound HEADERS frame with priority information specified.

Methods inherited from class Http2FrameListenerDecorator

onGoAwayRead, onPingAckRead, onPingRead, onPriorityRead, onPushPromiseRead, onRstStreamRead, onSettingsAckRead, onSettingsRead, onUnknownFrame, onWindowUpdateRead

Methods inherited from class Object

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

Field Details

connection

private final Http2Connection connection

strict

private final boolean strict

flowControllerInitialized

private boolean flowControllerInitialized

propertyKey

private final Http2Connection.PropertyKey propertyKey

maxAllocation

private final int maxAllocation

Constructor Details

DelegatingDecompressorFrameListener

@Deprecated
public DelegatingDecompressorFrameListener(Http2Connection connection,
 Http2FrameListener listener)

Deprecated.

Use DelegatingDecompressorFrameListener(Http2Connection, Http2FrameListener, int)

Create a new instance.

Parameters:

connection - the connection to read data which should be decompressed

listener - the delegate listener used by Http2FrameListenerDecorator

DelegatingDecompressorFrameListener

public DelegatingDecompressorFrameListener(Http2Connection connection,
 Http2FrameListener listener,
 int maxAllocation)

Create a new instance.

Parameters:

connection - the connection to read data which should be decompressed

listener - the delegate listener used by Http2FrameListenerDecorator

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

DelegatingDecompressorFrameListener

@Deprecated
public DelegatingDecompressorFrameListener(Http2Connection connection,
 Http2FrameListener listener,
 boolean strict)

Deprecated.

Use DelegatingDecompressorFrameListener(Http2Connection, Http2FrameListener, boolean, int)

Create a new instance.

Parameters:

connection - the connection to read data which should be decompressed

listener - the delegate listener used by Http2FrameListenerDecorator

strict - if `true`, ZlibWrapper.ZLIB will be used for the decoder, otherwise the decoder can fallback to ZlibWrapper.NONE

DelegatingDecompressorFrameListener

public DelegatingDecompressorFrameListener(Http2Connection connection,
 Http2FrameListener listener,
 boolean strict,
 int maxAllocation)

Create a new instance.

Parameters:

connection - the connection to read data which should be decompressed

listener - the delegate listener used by Http2FrameListenerDecorator

strict - if `true`, ZlibWrapper.ZLIB will be used for the decoder, otherwise the decoder can fallback to ZlibWrapper.NONE

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

Method Details

onDataRead

public int onDataRead(ChannelHandlerContext ctx,
 int streamId,
 ByteBuf data,
 int padding,
 boolean endOfStream)
               throws Http2Exception

Description copied from interface: Http2FrameListener

Handles an inbound DATA frame.

Specified by:

onDataRead in interface Http2FrameListener

Overrides:

onDataRead in class Http2FrameListenerDecorator

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the subject stream for the frame.

data - payload buffer for the frame. This buffer will be released by the codec.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive).

endOfStream - Indicates whether this is the last frame to be sent from the remote endpoint for this stream.

Returns:

the number of bytes that have been processed by the application. The returned bytes are used by the inbound flow controller to determine the appropriate time to expand the inbound flow control window (i.e. send WINDOW_UPDATE). Returning a value equal to the length of data + padding will effectively opt-out of application-level flow control for this frame. Returning a value less than the length of data + padding will defer the returning of the processed bytes, which the application must later return via Http2LocalFlowController.consumeBytes(Http2Stream, int). The returned value must be >= 0 and invalid input: '<'= data.readableBytes() + padding.

Throws:

Http2Exception

onHeadersRead

public void onHeadersRead(ChannelHandlerContext ctx,
 int streamId,
 Http2Headers headers,
 int padding,
 boolean endStream)
                   throws Http2Exception

Description copied from interface: Http2FrameListener

Handles an inbound HEADERS frame.

Only one of the following methods will be called for each HEADERS frame sequence. One will be called when the END_HEADERS flag has been received.

• Http2FrameListener.onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, boolean)
• Http2FrameListener.onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, short, boolean, int, boolean)
• Http2FrameListener.onPushPromiseRead(ChannelHandlerContext, int, int, Http2Headers, int)

To say it another way; the Http2Headers will contain all of the headers for the current message exchange step (additional queuing is not necessary).

Specified by:

onHeadersRead in interface Http2FrameListener

Overrides:

onHeadersRead in class Http2FrameListenerDecorator

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the subject stream for the frame.

headers - the received headers.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive).

endStream - Indicates whether this is the last frame to be sent from the remote endpoint for this stream.

Throws:

Http2Exception

onHeadersRead

public void onHeadersRead(ChannelHandlerContext ctx,
 int streamId,
 Http2Headers headers,
 int streamDependency,
 short weight,
 boolean exclusive,
 int padding,
 boolean endStream)
                   throws Http2Exception

Description copied from interface: Http2FrameListener

Handles an inbound HEADERS frame with priority information specified. Only called if END_HEADERS encountered.

Only one of the following methods will be called for each HEADERS frame sequence. One will be called when the END_HEADERS flag has been received.

• Http2FrameListener.onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, boolean)
• Http2FrameListener.onHeadersRead(ChannelHandlerContext, int, Http2Headers, int, short, boolean, int, boolean)
• Http2FrameListener.onPushPromiseRead(ChannelHandlerContext, int, int, Http2Headers, int)

To say it another way; the Http2Headers will contain all of the headers for the current message exchange step (additional queuing is not necessary).

Specified by:

onHeadersRead in interface Http2FrameListener

Overrides:

onHeadersRead in class Http2FrameListenerDecorator

Parameters:

ctx - the context from the handler where the frame was read.

streamId - the subject stream for the frame.

headers - the received headers.

streamDependency - the stream on which this stream depends, or 0 if dependent on the connection.

weight - the new weight for the stream.

exclusive - whether or not the stream should be the exclusive dependent of its parent.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive).

endStream - Indicates whether this is the last frame to be sent from the remote endpoint for this stream.

Throws:

Http2Exception

newContentDecompressor

protected EmbeddedChannel newContentDecompressor(ChannelHandlerContext ctx,
 CharSequence contentEncoding)
                                          throws Http2Exception

Returns a new EmbeddedChannel that decodes the HTTP2 message content encoded in the specified contentEncoding.

Parameters:

contentEncoding - the value of the content-encoding header

Returns:

a new ByteToMessageDecoder if the specified encoding is supported. null otherwise (alternatively, you can throw a Http2Exception to block unknown encoding).

Throws:

Http2Exception - If the specified encoding is not supported and warrants an exception

getTargetContentEncoding

protected CharSequence getTargetContentEncoding(CharSequence contentEncoding)
                                         throws Http2Exception

Returns the expected content encoding of the decoded content. This getMethod returns "identity" by default, which is the case for most decompressors.

Parameters:

contentEncoding - the value of the content-encoding header

Returns:

the expected content encoding of the new content.

Throws:

Http2Exception - if the contentEncoding is not supported and warrants an exception

initDecompressor

private void initDecompressor(ChannelHandlerContext ctx,
 int streamId,
 Http2Headers headers,
 boolean endOfStream)
                       throws Http2Exception

Checks if a new decompressor object is needed for the stream identified by streamId. This method will modify the content-encoding header contained in headers.

Parameters:

ctx - The context

streamId - The identifier for the headers inside headers

headers - Object representing headers which have been read

endOfStream - Indicates if the stream has ended

Throws:

Http2Exception - If the content-encoding is not supported

decompressor

DelegatingDecompressorFrameListener.Http2Decompressor decompressor(Http2Stream stream)