Class StreamBufferingEncoder
- All Implemented Interfaces:
Http2ConnectionEncoder
,Http2DataWriter
,Http2FrameWriter
,Http2SettingsReceivedConsumer
,Closeable
,AutoCloseable
Http2ConnectionEncoder
that dispatches all method call to another
Http2ConnectionEncoder
, until SETTINGS_MAX_CONCURRENT_STREAMS
is reached.
When this limit is hit, instead of rejecting any new streams this implementation buffers newly created streams and their corresponding frames. Once an active stream gets closed or the maximum number of concurrent streams is increased, this encoder will automatically try to empty its buffer and create as many new streams as possible.
If a GOAWAY
frame is received from the remote endpoint, all buffered writes for streams
with an ID less than the specified lastStreamId
will immediately fail with a
StreamBufferingEncoder.Http2GoAwayException
.
If the channel/encoder gets closed, all new and buffered writes will immediately fail with a
StreamBufferingEncoder.Http2ChannelClosedException
.
This implementation makes the buffering mostly transparent and is expected to be used as a
drop-in decorator of DefaultHttp2ConnectionEncoder
.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate final class
private static class
private static final class
private final class
static final class
Thrown if buffered streams are terminated due to this encoder being closed.static final class
Thrown byStreamBufferingEncoder
if buffered streams are terminated due to receipt of aGOAWAY
.private static final class
Nested classes/interfaces inherited from interface io.netty.handler.codec.http2.Http2FrameWriter
Http2FrameWriter.Configuration
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate boolean
private int
private final TreeMap
<Integer, StreamBufferingEncoder.PendingStream> Buffer for any streams and corresponding frames that could not be created due to the maximum concurrent stream limit being hit. -
Constructor Summary
ConstructorsConstructorDescriptionStreamBufferingEncoder
(Http2ConnectionEncoder delegate) StreamBufferingEncoder
(Http2ConnectionEncoder delegate, int initialMaxConcurrentStreams) -
Method Summary
Modifier and TypeMethodDescriptionprivate void
cancelGoAwayStreams
(StreamBufferingEncoder.GoAwayDetail goAwayDetail) private boolean
Determines whether or not we're allowed to create a new stream right now.void
close()
Closes this writer and frees any allocated resources.private boolean
isExistingStream
(int streamId) int
Indicates the number of streams that are currently buffered, awaiting creation.void
remoteSettings
(Http2Settings settings) Sets the settings for the remote endpoint of the HTTP/2 connection.private void
writeData
(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding, boolean endOfStream, ChannelPromise promise) Writes aDATA
frame to the remote endpoint.writeHeaders
(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int padding, boolean endStream, ChannelPromise promise) Writes a HEADERS frame to the remote endpoint.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.writeRstStream
(ChannelHandlerContext ctx, int streamId, long errorCode, ChannelPromise promise) Writes a RST_STREAM frame to the remote endpoint.Methods inherited from class io.netty.handler.codec.http2.DecoratingHttp2ConnectionEncoder
connection, consumeReceivedSettings, flowController, frameWriter, lifecycleManager, pollSentSettings
Methods inherited from class io.netty.handler.codec.http2.DecoratingHttp2FrameWriter
configuration, writeFrame, writeGoAway, writePing, writePriority, writePushPromise, 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
configuration, writeGoAway, writePing, writePriority, writePushPromise, writeSettings, writeSettingsAck, writeWindowUpdate
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Field Details
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pendingStreams
Buffer for any streams and corresponding frames that could not be created due to the maximum concurrent stream limit being hit. -
maxConcurrentStreams
private int maxConcurrentStreams -
closed
private boolean closed -
goAwayDetail
-
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Constructor Details
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StreamBufferingEncoder
-
StreamBufferingEncoder
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Method Details
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numBufferedStreams
public int numBufferedStreams()Indicates the number of streams that are currently buffered, awaiting creation. -
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 interfaceHttp2FrameWriter
- Overrides:
writeHeaders
in classDecoratingHttp2FrameWriter
- 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.
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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 interfaceHttp2FrameWriter
- Overrides:
writeHeaders
in classDecoratingHttp2FrameWriter
- 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.
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writeRstStream
public ChannelFuture writeRstStream(ChannelHandlerContext ctx, int streamId, long errorCode, ChannelPromise promise) Description copied from interface:Http2FrameWriter
Writes a RST_STREAM frame to the remote endpoint.- Specified by:
writeRstStream
in interfaceHttp2FrameWriter
- Overrides:
writeRstStream
in classDecoratingHttp2FrameWriter
- Parameters:
ctx
- the context to use for writing.streamId
- the stream for which to send the frame.errorCode
- the error code indicating the nature of the failure.promise
- the promise for the write.- Returns:
- the future for the write.
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writeData
public ChannelFuture writeData(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding, boolean endOfStream, ChannelPromise promise) Description copied from interface:Http2DataWriter
Writes aDATA
frame to the remote endpoint. This will result in one or more frames being written to the context.- Specified by:
writeData
in interfaceHttp2DataWriter
- Overrides:
writeData
in classDecoratingHttp2FrameWriter
- 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.
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remoteSettings
Description copied from interface:Http2ConnectionEncoder
Sets the settings for the remote endpoint of the HTTP/2 connection.- Specified by:
remoteSettings
in interfaceHttp2ConnectionEncoder
- Overrides:
remoteSettings
in classDecoratingHttp2ConnectionEncoder
- Throws:
Http2Exception
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close
public void close()Description copied from interface:Http2FrameWriter
Closes this writer and frees any allocated resources.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Specified by:
close
in interfaceHttp2FrameWriter
- Overrides:
close
in classDecoratingHttp2FrameWriter
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tryCreatePendingStreams
private void tryCreatePendingStreams() -
cancelGoAwayStreams
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canCreateStream
private boolean canCreateStream()Determines whether or not we're allowed to create a new stream right now. -
isExistingStream
private boolean isExistingStream(int streamId)
-