io.netty.handler.codec.http2

Class CompressorHttp2ConnectionEncoder

java.lang.Object

io.netty.handler.codec.http2.DecoratingHttp2FrameWriter

io.netty.handler.codec.http2.DecoratingHttp2ConnectionEncoder

io.netty.handler.codec.http2.CompressorHttp2ConnectionEncoder

All Implemented Interfaces:

Http2ConnectionEncoder, Http2DataWriter, Http2FrameWriter, Closeable, AutoCloseable

@UnstableApi
public class CompressorHttp2ConnectionEncoder
extends DecoratingHttp2ConnectionEncoder

A decorating HTTP2 encoder that will compress data frames according to the content-encoding header for each stream. The compression provided by this class will be applied to the data for the entire stream.

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.handler.codec.http2.Http2FrameWriter

Http2FrameWriter.Configuration

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_COMPRESSION_LEVEL
static int	DEFAULT_MEM_LEVEL
static int	DEFAULT_WINDOW_BITS

Constructor Summary

Constructors

Constructor and Description
CompressorHttp2ConnectionEncoder(Http2ConnectionEncoder delegate)
CompressorHttp2ConnectionEncoder(Http2ConnectionEncoder delegate, int compressionLevel, int windowBits, int memLevel)

Method Summary

Modifier and Type	Method and Description
protected CharSequence	getTargetContentEncoding(CharSequence contentEncoding) Returns the expected content encoding of the decoded content.
protected EmbeddedChannel	newContentCompressor(ChannelHandlerContext ctx, CharSequence contentEncoding) Returns a new EmbeddedChannel that encodes the HTTP2 message content encoded in the specified contentEncoding.
ChannelFuture	writeData(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding, boolean endOfStream, ChannelPromise promise) Writes a DATA frame to the remote endpoint.
ChannelFuture	writeHeaders(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int padding, boolean endStream, ChannelPromise promise) Writes a HEADERS frame to the remote endpoint.
ChannelFuture	writeHeaders(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int streamDependency, short weight, boolean exclusive, int padding, boolean endOfStream, ChannelPromise promise) Writes a HEADERS frame with priority specified to the remote endpoint.

Methods inherited from class io.netty.handler.codec.http2.DecoratingHttp2ConnectionEncoder

connection, flowController, frameWriter, lifecycleManager, pollSentSettings, remoteSettings

Methods inherited from class io.netty.handler.codec.http2.DecoratingHttp2FrameWriter

close, configuration, writeFrame, writeGoAway, writePing, writePriority, writePushPromise, writeRstStream, writeSettings, writeSettingsAck, writeWindowUpdate

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.handler.codec.http2.Http2ConnectionEncoder

writeFrame

Methods inherited from interface io.netty.handler.codec.http2.Http2FrameWriter

close, configuration, writeGoAway, writePing, writePriority, writePushPromise, writeRstStream, writeSettings, writeSettingsAck, writeWindowUpdate

Field Detail

DEFAULT_COMPRESSION_LEVEL

public static final int DEFAULT_COMPRESSION_LEVEL

See Also:

Constant Field Values

DEFAULT_WINDOW_BITS

public static final int DEFAULT_WINDOW_BITS

See Also:

Constant Field Values

DEFAULT_MEM_LEVEL

public static final int DEFAULT_MEM_LEVEL

See Also:

Constant Field Values

Constructor Detail

CompressorHttp2ConnectionEncoder

public CompressorHttp2ConnectionEncoder(Http2ConnectionEncoder delegate)

CompressorHttp2ConnectionEncoder

public CompressorHttp2ConnectionEncoder(Http2ConnectionEncoder delegate,
                                        int compressionLevel,
                                        int windowBits,
                                        int memLevel)

Method Detail

writeData

public ChannelFuture writeData(ChannelHandlerContext ctx,
                               int streamId,
                               ByteBuf data,
                               int padding,
                               boolean endOfStream,
                               ChannelPromise promise)

Description copied from interface: Http2DataWriter

Writes a DATA frame to the remote endpoint. This will result in one or more frames being written to the context.

Specified by:

writeData in interface Http2DataWriter

Overrides:

writeData in class DecoratingHttp2FrameWriter

Parameters:

ctx - the context to use for writing.

streamId - the stream for which to send the frame.

data - the payload of the frame. This will be released by this method.

padding - additional bytes that should be added to obscure the true content size. Must be between 0 and 256 (inclusive). A 1 byte padding is encoded as just the pad length field with value 0. A 256 byte padding is encoded as the pad length field with value 255 and 255 padding bytes appended to the end of the frame.

endOfStream - indicates if this is the last frame to be sent for the stream.

promise - the promise for the write.

Returns:

the future for the write.

writeHeaders

public ChannelFuture writeHeaders(ChannelHandlerContext ctx,
                                  int streamId,
                                  Http2Headers headers,
                                  int padding,
                                  boolean endStream,
                                  ChannelPromise promise)

Description copied from interface: Http2FrameWriter

Writes a HEADERS frame to the remote endpoint.

Specified by:

writeHeaders in interface Http2FrameWriter

Overrides:

writeHeaders in class DecoratingHttp2FrameWriter

Parameters:

ctx - the context to use for writing.

streamId - the stream for which to send the frame.

headers - the headers to be sent.

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

endStream - indicates if this is the last frame to be sent for the stream.

promise - the promise for the write.

Returns:

the future for the write. Section 10.5.1 states the following:

 The header block MUST be processed to ensure a consistent connection state, unless the connection is closed.
 

If this call has modified the HPACK header state you MUST throw a connection error.

If this call has NOT modified the HPACK header state you are free to throw a stream error.

writeHeaders

public ChannelFuture writeHeaders(ChannelHandlerContext ctx,
                                  int streamId,
                                  Http2Headers headers,
                                  int streamDependency,
                                  short weight,
                                  boolean exclusive,
                                  int padding,
                                  boolean endOfStream,
                                  ChannelPromise promise)

Description copied from interface: Http2FrameWriter

Writes a HEADERS frame with priority specified to the remote endpoint.

Specified by:

writeHeaders in interface Http2FrameWriter

Overrides:

writeHeaders in class DecoratingHttp2FrameWriter

Parameters:

ctx - the context to use for writing.

streamId - the stream for which to send the frame.

headers - the headers to be sent.

streamDependency - the stream on which this stream should depend, or 0 if it should depend on the connection.

weight - the weight for this stream.

exclusive - whether this stream should be the exclusive dependant of its parent.

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

endOfStream - indicates if this is the last frame to be sent for the stream.

promise - the promise for the write.

Returns:

the future for the write. Section 10.5.1 states the following:

 The header block MUST be processed to ensure a consistent connection state, unless the connection is closed.
 

If this call has modified the HPACK header state you MUST throw a connection error.

If this call has NOT modified the HPACK header state you are free to throw a stream error.

newContentCompressor

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

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

Parameters:

ctx - the context.

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 not supported and warrants an exception

getTargetContentEncoding

protected CharSequence getTargetContentEncoding(CharSequence contentEncoding)
                                         throws Http2Exception

Returns the expected content encoding of the decoded content. Returning contentEncoding is the default behavior, which is the case for most compressors.

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