Motivation:
The expression "not is success" can mean that either the future failed, or it has not yet completed.
However, many places where such an expression is used is expecting the future to have completed.
Specifically, they are expecting to be able to call `cause()` on the future.
It is both more correct, and semantically clearer, to call `isFailed()` instead of `!isSuccess()`.
Modification:
Change all places that used `!isSuccess()` to mean that the future had failed, to use `isFailed()`.
A few places are relying on `isSuccess()` returning `false` for _incomplete_ futures, and these places have been left unchanged.
Result:
Clearer code, with potentially fewer latent bugs.
Motivation:
The generics for the existing futures, promises, and listeners are too complicated.
This complication comes from the existence of `ChannelPromise` and `ChannelFuture`, which forces listeners to care about the particular _type_ of future being listened on.
Modification:
* Add a `FutureContextListener` which can take a context object as an additional argument. This allows our listeners to have the channel piped through to them, so they don't need to rely on the `ChannelFuture.channel()` method.
* Make the `FutureListener`, along with the `FutureContextListener` sibling, the default listener API, retiring the `GenericFutureListener` since we no longer need to abstract over the type of the future.
* Change all uses of `ChannelPromise` to `Promise<Void>`.
* Change all uses of `ChannelFuture` to `Future<Void>`.
* Change all uses of `GenericFutureListener` to either `FutureListener` or `FutureContextListener` as needed.
* Remove `ChannelFutureListener` and `GenericFutureListener`.
* Introduce a `ChannelFutureListeners` enum to house the constants that previously lived in `ChannelFutureListener`. These constants now implement `FutureContextListener` and take the `Channel` as a context.
* Remove `ChannelPromise` and `ChannelFuture` — all usages now rely on the plain `Future` and `Promise` APIs.
* Add static factory methods to `DefaultPromise` that allow us to create promises that are initialised as successful or failed.
* Remove `CompleteFuture`, `SucceededFuture`, `FailedFuture`, `CompleteChannelFuture`, `SucceededChannelFuture`, and `FailedChannelFuture`.
* Remove `ChannelPromiseNotifier`.
Result:
Cleaner generics and more straight forward code.
Bootstrap methods now return Future<Channel> instead of ChannelFuture
Motivation:
In #8516 it was proposed to at some point remove the specialised ChannelFuture and ChannelPromise.
Or at least make them not extend Future and Promise, respectively.
One pain point encountered in this discussion is the need to get access to the channel object after it has been initialised, but without waiting for the channel registration to propagate through the pipeline.
Modification:
Add a Bootstrap.createUnregistered method, which will return a Channel directly.
All other Bootstrap methods that previously returned ChannelFuture now return Future<Channel>
Result:
It's now possible to obtain an initialised but unregistered channel from a bootstrap, without blocking.
And the other bootstrap methods now only release their channels through the result of their futures, preventing racy access to the channels.
Motivation:
JUnit 5 is more expressive, extensible, and composable in many ways, and it's better able to run tests in parallel.
Modifications:
Use JUnit5 in codec-smtp tests
Result:
Related to https://github.com/netty/netty/issues/10757
Motivation:
https in xmlns URIs does not work and will let the maven release plugin fail:
```
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.779 s
[INFO] Finished at: 2020-11-10T07:45:21Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-release-plugin:2.5.3:prepare (default-cli) on project netty-parent: Execution default-cli of goal org.apache.maven.plugins:maven-release-plugin:2.5.3:prepare failed: The namespace xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" could not be added as a namespace to "project": The namespace prefix "xsi" collides with an additional namespace declared by the element -> [Help 1]
[ERROR]
```
See also https://issues.apache.org/jira/browse/HBASE-24014.
Modifications:
Use http for xmlns
Result:
Be able to use maven release plugin
Motivation:
HTTP is a plaintext protocol which means that someone may be able
to eavesdrop the data. To prevent this, HTTPS should be used whenever
possible. However, maintaining using https:// in all URLs may be
difficult. The nohttp tool can help here. The tool scans all the files
in a repository and reports where http:// is used.
Modifications:
- Added nohttp (via checkstyle) into the build process.
- Suppressed findings for the websites
that don't support HTTPS or that are not reachable
Result:
- Prevent using HTTP in the future.
- Encourage users to use HTTPS when they follow the links they found in
the code.
Motivation:
We need to ensure we not leak in tests. We did see some leaks reported related to HaProxyMessageEncoderTest on our CI.
Modifications:
- Use readSlice(...) and so not create new ByteBuf instances that need to be released
Result:
No more leaks
Motivation:
LGTM reports multiple issues. They need to be triaged,
and real ones should be fixed.
Modifications:
- Fixed multiple issues reported by LGTM, such as redundant conditions,
resource leaks, typos, possible integer overflows.
- Suppressed false-positives.
- Added a few testcases.
Result:
Fixed several possible issues, get rid of false alarms in the LGTM report.
Motivation:
Add support for HAProxyMessageEncoder.
This should help java based HAProxy server implementations propagate proxy information.
Modification:
Add public constructors for `HAProxyMessage`, `HAProxyTLV`, `HAProxySSLTLV`.
Add additional argument checks for `HAProxyMessage` and modify exceptions thrown when creating via public constructors directly.
Introduce a `@Sharable` `HAProxyMessageEncoder` which encodes a `HAProxyMessage` into a byte array.
Add an example `HAProxyServer` and `HAProxyClient` to `io.netty.example`
Result:
Fixes#10164
Motivation:
At the moment the next / prev references are not set to "null" in the DefaultChannelHandlerContext once the ChannelHandler is removed. This is bad as it basically let users still use the ChannelHandlerContext of a ChannelHandler after it is removed and may produce very suprising behaviour.
Modifications:
- Fail if someone tries to use the ChannelHandlerContext once the ChannelHandler was removed (for outbound operations fail the promise, for inbound fire the error through the ChannelPipeline)
- Fix some handlers to ensure we not use the ChannelHandlerContext after the handler was removed
- Adjust DefaultChannelPipeline / DefaultChannelHandlerContext to fixes races with removal / replacement of handlers
Result:
Cleanup behaviour and make it more predictable for pipeline modifications
Motivation:
ByteToMessageDecoder requires using an intermediate List to put results into. This intermediate list adds overhead (memory/CPU) which grows as the number of objects increases. This overhead can be avoided by directly propagating events through the ChannelPipeline via ctx.fireChannelRead(...). This also makes the semantics more clear and allows us to keep track if we need to call ctx.read() in all cases.
Modifications:
- Remove List from the method signature of ByteToMessageDecoder.decode(...) and decodeLast(...)
- Adjust all sub-classes
- Adjust unit tests
- Fix javadocs.
Result:
Adjust ByteToMessageDecoder as noted in https://github.com/netty/netty/issues/8525.
Motivation:
In line base decoders, lines are split by delimiter, but the delimiter may be \r\n or \r, so in decoding, if findEndOfLine finds delimiter of a line, the length of the delimiter may be 1 or 2, instead of DELIMITER_LENGTH, where the value is fixed to 2.
The second problem is that if the data to be decoded is too long, the decoder will discard too long data, and needs to record the length of the discarded bytes. In the original implementation, the discarded bytes are not accumulated, but are assigned to the currently discarded bytes.
Modification:
Modifications:
Dynamic calculation of the length of delimiter.
In discarding mode, add up the number of characters discarded each time.
Result:
Correctly handle all delimiters and also correctly handle too long frames.
Motivation:
HAProxyMessage should be released as it contains a list of TLV which hold a ByteBuf, otherwise, it may cause memory leaks.
Modification:
- Let HAProxyMessage extend AbstractReferenceCounted
- Adjust tests.
Result:
Fixes#9201
Motivation:
We can just use Objects.requireNonNull(...) as a replacement for ObjectUtil.checkNotNull(....)
Modifications:
- Use Objects.requireNonNull(...)
Result:
Less code to maintain.
Motivation:
We can use the diamond operator these days.
Modification:
Use diamond operator whenever possible.
Result:
More modern code and less boiler-plate.
Motivation:
Most of the maven modules do not explicitly declare their
dependencies and rely on transitivity, which is not always correct.
Modifications:
For all maven modules, add all of their dependencies to pom.xml
Result:
All of the (essentially non-transitive) depepdencies of the modules are explicitly declared in pom.xml
Automatic-Module-Name entry provides a stable JDK9 module name, when Netty is used in a modular JDK9 applications. More info: http://blog.joda.org/2017/05/java-se-9-jpms-automatic-modules.html
When Netty migrates to JDK9 in the future, the entry can be replaced by actual module-info descriptor.
Modification:
The POM-s are configured to put the correct module names to the manifest.
Result:
Fixes#7218.
