Motivation:
1. `ByteBuf` contains methods to writing `CharSequence` which optimized for UTF-8 and ASCII encodings. We can also apply optimization for ISO-8859-1.
2. In many places appropriate methods are not used.
Modifications:
1. Apply optimization for ISO-8859-1 encoding in the `ByteBuf#setCharSequence` realizations.
2. Apply appropriate methods for writing `CharSequences` into buffers.
Result:
Reduce overhead from string-to-bytes conversion.
Motivation:
Lz4FrameEncoder maintains internal state, but the life cycle of the buffer is not consistently managed. The buffer is allocated in handlerAdded but freed in close, but the buffer can still be used until handlerRemoved is called.
Modifications:
- Move the cleanup of the buffer from close to handlerRemoved
- Explicitly throw an EncoderException from Lz4FrameEncoder if the encode operation has finished and there isn't enough space to write data
Result:
No more NPE in Lz4FrameEncoder on the buffer.
Motivation:
JdkZlibDecoder will allocate a new buffer when the previous buffer is filled with inflated data, but JZlibDecoder will attempt to use the same buffer by resizing. This leads to inconsistent results when these two decoders that are intended to be functionality equivalent.
Modifications:
- JdkZlibDecoder should attempt to resize and reuse the existing buffer instead of creating multiple buffers
Result:
Fixes https://github.com/netty/netty/issues/6804
Motivation:
ByteToMessageDecoder#handlerRemoved will immediately release the cumulation buffer, but it is possible that a child class may still be using this buffer, and therefore use a dereferenced buffer.
Modifications:
- ByteToMessageDecoder#handlerRemoved and ByteToMessageDecoder#decode should coordinate to avoid the case where a child class is using the cumulation buffer but ByteToMessageDecoder releases that buffer.
Result:
Child classes of ByteToMessageDecoder are less likely to reference a released buffer.
Motivation:
We not correctly guarded against overflow and so call Base64.encode(...) with a big buffer may lead to an overflow when calculate the size of the out buffer.
Modifications:
Correctly guard against overflow.
Result:
Fixes [#6620].
Motivation:
If a read-only ByteBuf is passed to the ByteToMessageDecoder.channelRead(...) method we need to make a copy of it once we try to merge buffers for cumulation. This usually is not the case but can for example happen if the local transport is used. This was the cause of the leak report we sometimes saw during the codec-http2 tests, as we are using the local transport and write a read-only buffer. This buffer will then be passed to the peer channel and fired through the pipeline and so end up as the cumulation buffer in the ByteToMessageDecoder. Once the next fragement is received we tried to merge these and failed with a ReadOnlyBufferException which then produced a leak.
Modifications:
Ensure we copy the buffer if its read-only.
Result:
No more exceptions and so leak when a read-only buffer is passed to ByteToMessageDecoder.channelRead(...)
Motivation:
In an effort to better understand how the XmlFrameDecoder works, I consulted the tests to find a method that would reframe the inputs as per the Javadocs for that class. I couldn't find any methods that seemed to be doing it, so I wanted to add one to reinforce my understanding.
Modification:
Add a new test method to XmlFrameDecoder to assert that the reframing works as described.
Result:
New test method is added to XmlFrameDecoder
Motivation:
This pull request does not solve any problem but we find that several links in the code refer to project websites under the domain of http://code.google.com which are either moved to github or not maintained anymore.
Modification:
Update the project links from code.google.com to the relevant project in github.com
Motivation:
Lz4FrameEncoder uses internalNioBuffer but always passes in a value of 0 for the index. This should be readerIndex().
Modifications:
- change 0 to readerIndex()
Result:
More correct usage of internalNioBuffer in Lz4FrameEncoder.
Motivation:
DatagramPacketEncoder|Decoder should respect if the wrapped handler is sharable or not and depending on that be sharable or not.
Modifications:
- Delegate isSharable() to wrapped handler
- Add test-cases
Result:
Correct behavior
Motivation:
Base64#decode4to3 generally calculates an int value where the contents of the decodabet straddle bytes, and then uses a byte shifting or a full byte swapping operation to get the resulting contents. We can directly calculate the contents and avoid any intermediate int values and full byte swap operations. This will reduce the number of operations required during the decode operation.
Modifications:
- remove the intermediate int in the Base64#decond4to3 method.
- manually do the byte shifting since we are already doing bit/byte manipulations here anyways.
Result:
Base64#decode4to3 requires less operations to compute the end result.
Motivation:
The decode and encode method uses getByte(...) and setByte(...) in loops which can be very expensive because of bounds / reference-count checking. Beside this it also slows-down a lot when paranoid leak-detection is enabled as it will track each access.
Modifications:
- Pack bytes into int / short and so reduce operations on the ByteBuf
- Use ByteProcessor to reduce getByte calls.
Result:
Better performance in general. Also when you run the build with -Pleak the handler module will build in 1/4 of the time it took before.
Motivation:
We have our own ThreadLocalRandom implementation to support older JDKs . That said we should prefer the JDK provided when running on JDK >= 7
Modification:
Using ThreadLocalRandom implementation of the JDK when possible.
Result:
Make use of JDK implementations when possible.
Motivation:
To use jboss-marshalling extra command-line arguments are needed on JDK9+ as it makes use of reflection internally.
Modifications:
Skip jboss-marshalling tests when running on JDK9+ and init of MarshallingFactory fails.
Result:
Be able to build on latest JDK9 release.
Motivation:
We need to ensure we pass all tests when sun.misc.Unsafe is not present.
Modifications:
- Make *ByteBufAllocatorTest work whenever sun.misc.Unsafe is present or not
- Let Lz4FrameEncoderTest not depend on AbstractByteBufAllocator implementation details which take into account if sun.misc.Unsafe is present or not
Result:
Tests pass even without sun.misc.Unsafe.
Motivation:
We used various mocking frameworks. We should only use one...
Modifications:
Make usage of mocking framework consistent by only using Mockito.
Result:
Less dependencies and more consistent mocking usage.
Motivation:
Currently Netty does not wrap socket connect, bind, or accept
operations in doPrivileged blocks. Nor does it wrap cases where a dns
lookup might happen.
This prevents an application utilizing the SecurityManager from
isolating SocketPermissions to Netty.
Modifications:
I have introduced a class (SocketUtils) that wraps operations
requiring SocketPermissions in doPrivileged blocks.
Result:
A user of Netty can grant SocketPermissions explicitly to the Netty
jar, without granting it to the rest of their application.
Motivation:
LZ4FrameEncoder maintains an internal buffer of incoming data compress, and only writes out compressed data when a size threshold is reached. LZ4FrameEncoder does not override the flush() method, and thus the only way to flush data down the pipeline is via more data or close the channel.
Modifications:
Override the flush() function to flush on demand. Also overrode the allocateBuffer() function so we can more accurately size the output buffer (instead of needing to potatntially realloc via buffer.ensureWritable()).
Result:
Implementation works as described.
Motivation:
Thought there may be a bug so added a testcase to verify everything works as expected.
Modifications:
Added testcase
Result:
More test-coverage.
Motivation:
IntelliJ issues several warnings.
Modifications:
* `ClientCookieDecoder` and `ServerCookieDecoder`:
* `nameEnd`, `valueBegin` and `valueEnd` don't need to be initialized
* `keyValLoop` loop doesn't been to be labelled, as it's the most inner one (same thing for labelled breaks)
* Remove `if (i != headerLen)` as condition is always true
* `ClientCookieEncoder` javadoc still mention old logic
* `DefaultCookie`, `ServerCookieEncoder` and `DefaultHttpHeaders` use ternary ops that can be turned into simple boolean ones
* `DefaultHeaders` uses a for(int) loop over an array. It can be turned into a foreach one as javac doesn't allocate an iterator to iterate over arrays
* `DefaultHttp2Headers` and `AbstractByteBuf` `equal` can be turned into a single boolean statement
Result:
Cleaner code
Motivation:
* DefaultHeaders from netty-codec has some duplicated logic for header date parsing
* Several classes keep on using deprecated HttpHeaderDateFormat
Modifications:
* Move HttpHeaderDateFormatter to netty-codec and rename it into HeaderDateFormatter
* Make DefaultHeaders use HeaderDateFormatter
* Replace HttpHeaderDateFormat usage with HeaderDateFormatter
Result:
Faster and more consistent code
Motiviation:
We used ReferenceCountUtil.releaseLater(...) in our tests which simplifies a bit the releasing of ReferenceCounted objects. The problem with this is that while it simplifies stuff it increase memory usage a lot as memory may not be freed up in a timely manner.
Modifications:
- Deprecate releaseLater(...)
- Remove usage of releaseLater(...) in tests.
Result:
Less memory needed to build netty while running the tests.
Motivation:
2c78902ebc ensured buffers were released in the general case but didn't clean up an extra release in LzmaFrameEncoderTest#testCompressionOfBatchedFlowOfData which lead to a double release.
Modifications:
LzmaFrameEncoderTest#testCompressionOfBatchedFlowOfData should not explicitly release the buffer because decompress will release the buffer
Result:
No more reference count exception and failed test.
Motivation:
c1932a8537 made an assumption that the LzmaInputStream which wraps a ByteBufInputStream would delegate the close operation to the wrapped stream. This assumption is not true and thus we still had a leak. An issue has been logged with our LZMA dependency https://github.com/jponge/lzma-java/issues/14.
Modifications:
- Force a close on the wrapped stream
Result:
No more leak.
Motivation:
Netty provides a adaptor from ByteBuf to Java's InputStream interface. The JDK Stream interfaces have an explicit lifetime because they implement the Closable interface. This lifetime may be differnt than the ByteBuf which is wrapped, and controlled by the interface which accepts the JDK Stream. However Netty's ByteBufInputStream currently does not take reference count ownership of the underlying ByteBuf. There may be no way for existing classes which only accept the InputStream interface to communicate when they are done with the stream, other than calling close(). This means that when the stream is closed it may be appropriate to release the underlying ByteBuf, as the ownership of the underlying ByteBuf resource may be transferred to the Java Stream.
Motivation:
- ByteBufInputStream.close() supports taking reference count ownership of the underyling ByteBuf
Result:
ByteBufInputStream can assume reference count ownership so the underlying ByteBuf can be cleaned up when the stream is closed.
Motivation:
The unit tests for the compression encoders/decoders may write buffers to an EmbeddedChannel but then may not release buffer or close the channel after the test. This may result in buffer leaks.
Modifications:
- Call channel.finishAndReleaseAll() after each test
Result:
Fixes https://github.com/netty/netty/issues/6007
Motivation:
ObjectOutputStream uses a Channel Attribute to cache a ObjectOutputStream which is backed by a ByteBuf that may be released after an object is encoded and the underlying buffer is written to the channel. On subsequent encode operations the cached ObjectOutputStream will be invalid and lead to a reference count exception.
Modifications:
- CompatibleObjectEncoder should not cache a ObjectOutputStream.
Result:
CompatibleObjectEncoder doesn't use a cached object backed by a released ByteBuf.
