Motivation
Pipeline handlers are free to "take control" of input buffers if they have singular refcount - in particular to mutate their raw data if non-readonly via discarding of read bytes, etc.
However there are various places (primarily unit tests) where a wrapped byte-array buffer is passed in and the wrapped array is assumed not to change (used after the wrapped buffer is passed to EmbeddedChannel.writeInbound()). This invalid assumption could result in unexpected errors, such as those exposed by #8931.
Modifications
Anywhere that the data passed to writeInbound() might be used again, ensure that either:
- A copy is used rather than wrapping a shared byte array, or
- The buffer is otherwise protected from modification by making it read-only
For the tests, copying is preferred since it still allows the "mutating" optimizations to be exercised.
Results
Avoid possible errors when pipeline assumes it has full control of input buffer.
Motivation:
Add user possibility to skip the evaluation of certain web socket extension,
for example we can skip compression extension for messages that already compressed or very small and etc.
Modification:
This pull request is related with #5669
Result:
User can set to WebSocketClientExtensionHandshaker or WebSocketServerExtensionHandshaker a filter to skip the evaluation of certain extension.
Motivation:
We need to update to a new checkstyle plugin to allow the usage of lambdas.
Modifications:
- Update to new plugin version.
- Fix checkstyle problems.
Result:
Be able to use checkstyle plugin which supports new Java syntax.
Motivation:
As mentioned in RFC 7692 :
The "server_no_context_takeover" Extension Parameter should be used on server side for compression and on client side for decompression.
The "client_no_context_takeover" Extension Parameter should be used on client side for compression and on server side for decompression.
Right now, in PerMessageDeflateClientExtensionHandshaker, the decoder uses clientNoContext instead of serverNoContext and the encoder uses serverNoContext instead of clientNoContext.
The same inversion is present in PerMessageDeflateServerExtensionHandshaker: the decoder uses
serverNoContext instead of clientNoContext, while the encoder uses serverNoContext instead of clientNoContext. Besides the context inversion, the sliding window sizes seem to be inversed as well.
Modification:
Inverse clientNoContext with serverNoContext and clientWindowSize with serverWindowSize for both the Decoder and Encoder in PerMessageDeflateServerExtensionHandshaker and PerMessageDeflateClientExtensionHandshaker.
Result:
This fixes the decompression fail in the case that one of the contexts is set and the other one is not.
Motivation:
At the moment the user is responsible to increase the writer index of the composite buffer when a new component is added. We should add some methods that handle this for the user as this is the most popular usage of the composite buffer.
Modifications:
Add new methods that autoamtically increase the writerIndex when buffers are added.
Result:
Easier usage of CompositeByteBuf.
Motivation:
If the Connection header contains multiple values (which is valid) we fail to detect a websocket upgrade
Modification:
- Add new method which allows to check if a header field contains a specific value (and also respect multiple header values)
- Use this method to detect handshake
Result:
Correct detect handshake if Connection header contains multiple values (seperated by ',').
Motivation:
If the ZlibCodecFactory can support using a custom window size we should support it by default in the websocket extensions as well.
Modifications:
Detect if a custom window size can be handled by the ZlibCodecFactory and if so enable it by default for PerMessageDeflate*ExtensionHandshaker.
Result:
Support window size flag by default in most installations.
Motivation:
WebSocketClientCompressionHandler is stateless so it should be @Sharable.
Modifications:
Add @Sharable annotation to WebSocketClientCompressionHandler, make constructor private and add static field to get the instance.
Result:
Less object creation.
Motivation:
Warnings in IDE, unclean code, negligible performance impact.
Modification:
Deletion of unused imports
Result:
No more warnings in IDE, cleaner code, negligible performance improvement.
Motivation:
We have websocket extension support (with compression) in old master. We should port this to 4.1
Modifications:
Backport relevant code.
Result:
websocket extension support (with compression) is now in 4.1.
