Motivation:
Even if a handler called ctx.fireChannelReadComplete(), the next handler
should not get its channelReadComplete() invoked if fireChannelRead()
was not invoked before.
Modifications:
- Ensure channelReadComplete() is invoked only when the handler of the
current context actually produced a message, because otherwise there's
no point of triggering channelReadComplete().
i.e. channelReadComplete() must follow channelRead().
- Fix a bug where ctx.read() was not called if the handler of the
current context did not produce any message, making the connection
stall. Read the new comment for more information.
Result:
- channelReadComplete() is invoked only when it makes sense.
- No stale connection
Motivation:
The JdkZlibDecoder and JZlibDecoder call isReadable and readableBytes in the same method. There is an opportunity to reduce the number of methods calls to just use readableBytes. JdkZlibDecoder reads from a ByteBuf with an absolute index instead of using readerIndex()
Modifications:
- Use readableBytes where isReadable was used
- Correct absolute ByteBuf index to be relative to readerIndex()
Result:
Less method calls duplicating work and preventing an index out of bounds exception.
Motivation:
There are two member variables (addAllVisitor, setAllVisitor) which are likely not to be used in the majority of use cases.
Modifications:
Remove these member variables and rely on a method to return a new object when needed.
Result:
Two less member variables for each DefaultHeaders instance.
Motivation:
The Headers interface had two member variables (addAllVisitor, setAllVisitor) which are not necessarily always needed but are always instantiated. This may result in excess memory being used.
Modifications:
- addAllVisitor will be accessed via a method addAllVisitor() which will use lazy initialization.
- setAllVisitor will be accessed via a method addAllVisitor() which will use lazy initialization.
Result:
Potential memory savings by using lazy initialization.
Motivation:
Decompression handlers contain heavy use of switch-case statements. We
use compact indentation style for 'case' so that we utilize our screen
real-estate more efficiently.
Also, the following decompression handlers do not need to run a loop,
because ByteToMessageDecoder already runs a loop for them:
- FastLzFrameDecoder
- Lz4FrameDecoder
- LzfDecoder
Modifications:
- Fix indentations
- Do not wrap the decoding logic with a for loop when unnecessary
- Handle the case where a FastLz/Lzf frame contains no data properly so
that the buffer does not leak and less garbage is produced.
Result:
- Efficiency
- Compact source code
- No buffer leak
Motivation:
Currently when there are bytes left in the cumulation buffer we do a byte copy to produce the input buffer for the decode method. This can put quite some overhead on the impl.
Modification:
- Use a CompositeByteBuf to eliminate the byte copy.
- Allow to specify if a CompositeBytebug should be used or not as some handlers can only act on one ByteBuffer in an efficient way (like SslHandler :( ).
Result:
Performance improvement as shown in the following benchmark.
Without this patch:
[xxx@xxx ~]$ ./wrk-benchmark
Running 5m test @ http://xxx:8080/plaintext
16 threads and 256 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 20.19ms 38.34ms 1.02s 98.70%
Req/Sec 241.10k 26.50k 303.45k 93.46%
1153994119 requests in 5.00m, 155.84GB read
Requests/sec: 3846702.44
Transfer/sec: 531.93MB
With the patch:
[xxx@xxx ~]$ ./wrk-benchmark
Running 5m test @ http://xxx:8080/plaintext
16 threads and 256 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 17.34ms 27.14ms 877.62ms 98.26%
Req/Sec 252.55k 23.77k 329.50k 87.71%
1209772221 requests in 5.00m, 163.37GB read
Requests/sec: 4032584.22
Transfer/sec: 557.64MB
Modifications:
Converted AsciiString into a String by calling toString() method before comparing with equals(). Also added a unit-test to show that it works.
Result:
Major violation is gone. Code is correct.
Motivation:
This fixes issue 3168 where HttpObjectAggregator does not suppress
channelReadComplete() when aggregation is not yet finished.
Modifications:
Ignore channelReadComplete until a message completes aggregation.
MessageAggregator currently tracks the currentMessage being aggregated.
This variable transitions to non-null when aggregation begins and back
to null when aggregation completes or fails. When the currentMessage is
null, it is safe to issue a channelReadComplete because the
corresponding channelRead will have completed aggregation.
Result:
channelReadComplete will only fire one time on each completed message
aggregation.
Motivation:
The new Headers interface contains methods to getTimeMillis but no add/set/contains variants. These should be added for consistency.
Modifications:
- Add three new methods: addTimeMillis, setTimeMillis, containsTimeMillis to the Headers interface.
- Add a new method to the Headers.ValueConverter interface: T convertTimeMillis(long)
- Bring these new interfaces up the class hierarchy
Result:
All Headers classes have setters/getters for timeMillis.
Motivation:
Found performance issues via FindBugs and PMD.
Modifications:
- Removed unnecessary boxing/unboxing operations in DefaultTextHeaders.convertToInt(CharSequence) and DefaultTextHeaders.convertToLong(CharSequence). A boxed primitive is created from a string, just to extract the unboxed primitive value.
- Added a static modifier for DefaultHttp2Connection.ParentChangedEvent class. This class is an inner class, but does not use its embedded reference to the object which created it. This reference makes the instances of the class larger, and may keep the reference to the creator object alive longer than necessary.
- Added a static compiled Pattern to avoid compile it each time it is used when we need to replace some part of authority.
- Improved using of StringBuilders.
Result:
Performance improvements.
Motivation:
Currently, we only test our ZlibEncoders against our ZlibDecoders. It is
convenient to write such tests, but it does not necessarily guarantee
their correctness. For example, both encoder and decoder might be faulty
even if the tests pass.
Modifications:
Add another test that makes sure that our GZIP encoder generates the
GZIP trailer, using the fact that GZIPInputStream raises an EOFException
when GZIP trailer is missing.
Result:
More coverage for GZIP compression
Motiviation:
The HttpContentEncoder does not account for a EmptyLastHttpContent being provided as input. This is useful in situations where the client is unable to determine if the current content chunk is the last content chunk (i.e. a proxy forwarding content when transfer encoding is chunked).
Modifications:
- HttpContentEncoder should not attempt to compress empty HttpContent objects
Result:
HttpContentEncoder supports a EmptyLastHttpContent to terminate the response.
Motivation:
CollectionUtils has only one method and it is used only in DefaultHeaders.
Modification:
Move CollectionUtils.equals() to DefaultHeaders and make it private
Result:
One less class to expose in our public API
Motiviation:
Some of the contains method signatures did not include the correct type of parameters for the method names. Also these same methods were not using the correct conversion methods but instead the generic object conversion methods.
Modifications
-Correct the parameter types of the contains methods to match the method name
-Correct the implementation of these methods to use the correct conversion methods
Result:
Headers contains signatures are more correct and correct conversion methods are used.
Motivation:
- There are still various inspector warnings to fix.
- ValueConverter.convert() methods need to end with the type name like
other methods in Headers, such as setInt() and addInt(), for more
consistency
Modifications:
- Fix all inspector warnings
- Rename ValueConverter.convert() to convert<type>()
Result:
- Cleaner code
- Consistency
Motivation:
Headers within netty do not cleanly share a common class hierarchy. As a result some header types support some operations
and don't support others. The consolidation of the class hierarchy will allow for maintenance and scalability for new codec.
The existing hierarchy also has a few short comings such as it is not clear when data conversions are happening. This
could result unintentionally getting back a collection or iterator where a conversion on each entry must happen.
The current headers algorithm also prepends all elements which means to find the first element or return a collection
in insertion order often requires a complete traversal followed by a collections.reverse call.
Modifications:
-Provide a generic base class which provides all the implementation for headers in netty
-Provide an extension to this class which allows for name type conversions to happen (to accommodate legacy CharSequence to String conversions)
-Update the headers interface to clarify when conversions will happen.
-Update the headers data structure so that appends are done to avoid unnecessary iteration or collection reversal.
Result:
-More unified class hierarchy for headers in netty
-Improved headers data structure and algorithms
-headers API more clearly identify when conversions are required.
Motivation:
Make it much more readable code.
Modifications:
- Added states of decompression.
- Refactored decode(...) method to use this states.
Result:
Much more readable decoder which looks like other compression decoders.
Motivation:
HTTP/2 codec does not properly test exception passed to
exceptionCaught() for instanceof Http2Exception (since the exception
will always be wrapped in a PipelineException), so it will never
properly handle Http2Exceptions in the pipeline.
Also if any streams are present, the connection close logic will execute
twice when a pipeline exception. This is because the exception logic
calls ctx.close() which then triggers the handleInActive() logic to
execute. This clears all of the remaining streams and then attempts to
run the closeListener logic (which has already been run).
Modifications:
Changed exceptionCaught logic to properly extract Http2Exception from
the PipelineException. Also added logic to the closeListener so that is
only run once.
Changed Http2CodecUtil.toHttp2Exception() to avoid NPE when creating
an exception with cause.getMessage().
Refactored Http2ConnectionHandler to more cleanly separate inbound and
outbound flows (Http2ConnectionDecoder/Http2ConnectionEncoder).
Added a test for verifying that a pipeline exception closes the
connection.
Result:
Exception handling logic is tidied up.
Motivation:
A discovered typo in LzmaFrameEncoder constructor when we check `lc + lp` for better compatibility.
Modifications:
Changed `lc + pb` to `lc + lp`.
Result:
Correct check of `lc + lp` value.
Motivation:
The HTTP/2 spec does not restrict headers to being String. The current
implementation of the HTTP/2 codec uses Strings as header keys and
values. We should change this so that header keys and values allow
binary values.
Modifications:
Making Http2Headers based on AsciiString, which is a wrapper around a
byte[].
Various changes throughout the HTTP/2 codec to use the new interface.
Result:
HTTP/2 codec no longer requires string headers.
Motivation:
LZMA compression algorithm has a very good compression ratio.
Modifications:
- Added `lzma-java` library which implements LZMA algorithm.
- Implemented LzmaFrameEncoder which extends MessageToByteEncoder and provides compression of outgoing messages.
- Added tests to verify the LzmaFrameEncoder and how it can compress data for the next uncompression using the original library.
Result:
LZMA encoder which can compress data using LZMA algorithm.
Motivation:
ExtensionRegistry is a subclass of ExtensionRegistryLite. The ProtobufDecoder
doesn't use the registry directly, it simply passes it through to the Protobuf
API. The Protobuf calls in question are themselves written in terms
ExtensionRegistryLite not ExtensionRegistry.
Modifications:
Require ExtensionRegistryLite instead of ExtensionRegistry in ProtobufDecoder.
Result:
Consumers can use ExtensionRegistryLite with ProtobufDecoder.
Motivation:
The priority information reported by the HTTP/2 to HTTP tranlsation layer is not correct in all situations.
The HTTP translation layer is not using the Http2Connection.Listener interface to track tree restructures.
This incorrect information is being sent up to clients and is misleading.
Modifications:
-Restructure InboundHttp2ToHttpAdapter to allow a default data/header mode
-Extend this interface to provide an optional priority translation layer
Result:
-Priority information being correctly reported in HTTP/2 to HTTP translation layer
-Cleaner code with seperation of concerns (optional priority conversion).
Related issue: #2821
Motivation:
There's no way for a user to change the default ZlibEncoder
implementation.
It is already possible to change the default ZlibDecoder implementation.
Modification:
Add a new system property 'io.netty.noJdkZlibEncoder'.
Result:
A user can disable JDK ZlibEncoder, just like he or she can disable JDK
ZlibDecoder.
Motivation:
HTTP/2 draft 14 came out a couple of weeks ago and we need to keep up
with the spec.
Modifications:
-Revert back to dispatching FullHttpMessage objects instead of individual HttpObjects
-Corrections to HttpObject comparitors to support test cases
-New test cases to support sending headers immediatley
-Bug fixes cleaned up to ensure the message flow is terminated properly
Result:
Netty HTTP/2 to HTTP/1.x translation layer will support the HTTP/2 draft message flow.
Motivation:
We have some duplicated code that can be reused.
Modifications:
Create package private class called CodecUtil that now contains the shared code / helper method.
Result:
Less code-duplication
Motivation:
ByteToMessageCodec miss to check for @Sharable annotation in one of its constructors.
Modifications:
Ensure we call checkForSharableAnnotation in all constructors.
Result:
After your change, what will change.
Motivation:
LZ4 compression codec provides sending and receiving data encoded by very fast LZ4 algorithm.
Modifications:
- Added `lz4` library which implements LZ4 algorithm.
- Implemented Lz4FramedEncoder which extends MessageToByteEncoder and provides compression of outgoing messages.
- Added tests to verify the Lz4FramedEncoder and how it can compress data for the next uncompression using the original library.
- Implemented Lz4FramedDecoder which extends ByteToMessageDecoder and provides uncompression of incoming messages.
- Added tests to verify the Lz4FramedDecoder and how it can uncompress data after compression using the original library.
- Added integration tests for Lz4FramedEncoder/Decoder.
Result:
Full LZ4 compression codec which can compress/uncompress data using LZ4 algorithm.
Motivation:
ByteToMessageDecoder and ReplayingDecoder have incorrect javadocs in some places.
Modifications:
Fix incorrect javadocs for both classes.
Result:
Correct javadocs for both classes
Motivation:
FastLZ compression codec provides sending and receiving data encoded by fast FastLZ algorithm using block mode.
Modifications:
- Added part of `jfastlz` library which implements FastLZ algorithm. See FastLz class.
- Implemented FastLzFramedEncoder which extends MessageToByteEncoder and provides compression of outgoing messages.
- Implemented FastLzFramedDecoder which extends ByteToMessageDecoder and provides uncompression of incoming messages.
- Added integration tests for `FastLzFramedEncoder/Decoder`.
Result:
Full FastLZ compression codec which can compress/uncompress data using FastLZ algorithm.
Motivation:
The HTTP/2 codec currently provides direct callbacks to access stream events/data. The HTTP/2 codec provides the protocol support for HTTP/2 but it does not pass messages up the context pipeline. It would be nice to have a decoder which could collect the data framed by HTTP/2 and translate this into traditional HTTP type objects. This would allow the traditional Netty context pipeline to be used to separate processing concerns (i.e. HttpContentDecompressor). It would also be good to have a layer which can translate FullHttp[Request|Response] objects into HTTP/2 frame outbound events.
Modifications:
Introduce a new InboundHttp2ToHttpAdapter and supporting classes which will translate HTTP/2 stream events/data into HttpObject objects. Introduce a new DelegatingHttp2HttpConnectionHandler which will translate FullHttp[Request|Response] objects to HTTP/2 frame events.
Result:
Introduced HTTP/2 frame events to HttpObject layer.
Introduced FullHttp[Request|Response] to HTTP/2 frame events.
Introduced new unit tests to support new code.
Updated HTTP/2 client example to use new code.
Miscelaneous updates and bug fixes made to support new code.
Motivation:
It is often very expensive to instantiate an exception. TextHeader
should not raise an exception when it failed to find a header or when
its header value is not valid.
Modification:
- Change the return type of the getter methods to Integer and Long so
that null is returned when no header is found or its value is invalid
- Update Javadoc
Result:
- Fixes#2758
- No unnecessary instantiation of exceptions
Related issue: #2649 and #2745
Motivation:
At the moment there is no way to get and remove a header with one call.
This means you need to search the headers two times. We should add
getAndRemove(...) to allow doing so with one call.
Modifications:
Add getAndRemove(...) and getUnconvertedAndRemove(...) and their
variants
Result:
More efficient API
Motivation:
Before this changes Bzip2BitReader and Bzip2BitWriter accessed to ByteBuf byte by byte. So tests for Bzip2 compression codec takes a lot of time if we ran them with paranoid level of resource leak detection. For more information see comments to #2681 and #2689.
Modifications:
- Increased size of bit buffers from 8 to 64 bits.
- Improved reading and writing operations.
- Save link to incoming ByteBuf inside Bzip2BitReader.
- Added methods to check possible readable bits and bytes in Bzip2BitReader.
- Updated Bzip2 classes to use new API of Bzip2BitReader.
- Added new constants to Bzip2Constants.
Result:
Increased size of bit buffers and improved performance of Bzip2 compression codec (for general work by 13% and for tests with paranoid level of resource leak detection by 55%).
Motivation:
In ReplayingDecoder / ByteToMessageDecoder channelInactive(...) method we try to decode a last time and fire all decoded messages throw the pipeline before call ctx.fireChannelInactive(...). To keep the correct order of events we also need to call ctx.fireChannelReadComplete() if we read anything.
Modifications:
- Channel channelInactive(...) to call ctx.fireChannelReadComplete() if something was decoded
- Move out.recycle() to finally block
Result:
Correct order of events.
Motivation:
Complicated code of Bzip2 tests with some unnecessary actions.
Modifications:
- Reduce size of BYTES_LARGE array of random test data for Bzip2 tests.
- Removed unnecessary creations of EmbeddedChannel instances in Bzip2 tests.
- Simplified tests in Bzip2DecoderTest which expect exception.
- Removed unnecessary testStreamInitialization() from Bzip2EncoderTest.
Result:
Reduced time to test the 'codec' package by 7 percent, simplified code of Bzip2 tests.
Motivation:
Duplicated code of integration tests for different compression codecs.
Modifications:
- Added abstract class IntegrationTest which contains common tests for any compression codec.
- Removed common tests from Bzip2IntegrationTest and LzfIntegrationTest.
- Implemented abstract methods of IntegrationTest in Bzip2IntegrationTest, LzfIntegrationTest and SnappyIntegrationTest.
Result:
Removed duplicated code of integration tests for compression codecs and simplified an addition of integration tests for new compression codecs.
Motivation:
Sometimes we have a 'build time out' error because tests for bzip2 codec take a long time.
Modifications:
Removed cycles from Bzip2EncoderTest.testCompression(byte[]) and Bzip2DecoderTest.testDecompression(byte[]).
Result:
Reduced time to test the 'codec' package by 30 percent.
Motivation:
Fixed founded mistakes in compression codecs.
Modifications:
- Changed return type of ZlibUtil.inflaterException() from CompressionException to DecompressionException
- Updated @throws in javadoc of JZlibDecoder to throw DecompressionException instead of CompressionException
- Fixed JdkZlibDecoder to throw DecompressionException instead of CompressionException
- Removed unnecessary empty lines in JdkZlibEncoder and JZlibEncoder
- Removed public modifier from Snappy class
- Added MAX_UNCOMPRESSED_DATA_SIZE constant in SnappyFramedDecoder
- Used in.readableBytes() instead of (in.writerIndex() - in.readerIndex()) in SnappyFramedDecoder
- Added private modifier for enum ChunkType in SnappyFramedDecoder
- Fixed potential bug (sum overflow) in Bzip2HuffmanAllocator.first(). For more info, see http://googleresearch.blogspot.ru/2006/06/extra-extra-read-all-about-it-nearly.html
Result:
Fixed sum overflow in Bzip2HuffmanAllocator, improved exceptions in ZlibDecoder implementations, hid Snappy class
Motivation:
We create a new CompactObjectInputStream with ByteBufInputStream in ObjectDecoder.decode(...) method and don't close this InputStreams before return statement.
Modifications:
Save link to the ObjectInputStream and close it before return statement.
Result:
Close InputStreams and clean up unused resources. It will be better for GC.
