@UnstableApi public final class WeightedFairQueueByteDistributor extends Object implements StreamByteDistributor
StreamByteDistributor
that is sensitive to stream priority and uses
Weighted Fair Queueing approach for distributing
bytes.
Inspiration for this distributor was taken from Linux's Completely Fair Scheduler to model the distribution of bytes to simulate an "ideal multi-tasking CPU", but in this case we are simulating an "ideal multi-tasking NIC".
Each write operation will use the allocationQuantum(int)
to know how many more bytes should be allocated
relative to the next stream which wants to write. This is to balance fairness while also considering goodput.
StreamByteDistributor.StreamState, StreamByteDistributor.Writer
Constructor and Description |
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WeightedFairQueueByteDistributor(Http2Connection connection) |
Modifier and Type | Method and Description |
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void |
allocationQuantum(int allocationQuantum)
Sets the amount of bytes that will be allocated to each stream.
|
boolean |
distribute(int maxBytes,
StreamByteDistributor.Writer writer)
Distributes up to
maxBytes to those streams containing streamable bytes and
iterates across those streams to write the appropriate bytes. |
void |
updateStreamableBytes(StreamByteDistributor.StreamState state)
Called when the streamable bytes for a stream has changed.
|
public WeightedFairQueueByteDistributor(Http2Connection connection)
public void updateStreamableBytes(StreamByteDistributor.StreamState state)
StreamByteDistributor
updateStreamableBytes
in interface StreamByteDistributor
public boolean distribute(int maxBytes, StreamByteDistributor.Writer writer) throws Http2Exception
StreamByteDistributor
maxBytes
to those streams containing streamable bytes and
iterates across those streams to write the appropriate bytes. Criteria for
traversing streams is undefined and it is up to the implementation to determine when to stop
at a given stream.
The streamable bytes are not automatically updated by calling this method. It is up to the
caller to indicate the number of bytes streamable after the write by calling
StreamByteDistributor.updateStreamableBytes(StreamState)
.
distribute
in interface StreamByteDistributor
maxBytes
- the maximum number of bytes to write.true
if there are still streamable bytes that have not yet been written,
otherwise false
.Http2Exception
- If an internal exception occurs and internal connection state would otherwise be
corrupted.public void allocationQuantum(int allocationQuantum)
allocationQuantum
- the amount of bytes that will be allocated to each stream. Must be > 0.Copyright © 2008–2017 The Netty Project. All rights reserved.