Motivation:
We should make use of the Inflater methods that allows us to use a ByteBuffer to be able to reduce memory copies when running on Java11+.
Modifications:
Add new class that uses MethodHandles to call the right methods when running on Java11
Result:
Replaces parts of https://github.com/netty/netty/pull/10228
Motivation:
We had multiple bugs in JdkZlibDecoder which could lead to decoding errors when the data was received in a fragmentated manner.
Modifications:
- Correctly handle skipping of comments
- Correctly handle footer / header decoding
- Add unit test that verifies the correct handling of fragmentation
Result:
Fixes https://github.com/netty/netty/issues/10875
Motivation:
We need to carefully check for null before we pass the cumulation buffer into decodeLast as callDecode(...) may have removed the codec already and so set cumulation to null.
Modifications:
- Check for null and if we see null use Unpooled.EMPTY_BUFFEr
- Only call decodeLast(...) if callDecode(...) didnt remove the handler yet.
Result:
Fixes https://github.com/netty/netty/issues/10802
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:
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:
Avoid implicit conversions to narrower types in
AbstractMemoryHttpData and Bzip2HuffmanStageEncoder classes
reported by LGTM.
Modifications:
Updated the classes to avoid implicit casting to narrower types.
It doesn't look like that an integer overflow is possible there,
therefore no checks for overflows were added.
Result:
No warnings about implicit conversions to narrower types.
Motivation:
We should provide details about why an IOOBE was thrown
Modification:
Add IndexOutOfBoundsException error information in io.netty.util.internal.AppendableCharSequence and io.netty.handler.codec.CodecOutputList class
Result:
Easier to debug
Motivation:
`Date`, `Expires`, and `Set-Cookie` headers are being generated with a 1-digit day of month,
e.g. `Sun, 6 Nov 1994 08:49:37 GMT`. RFC 2616 specifies that `Date` and `Expires` headers should
use "a fixed-length subset of that defined by RFC 1123" which includes a 2-digit day of month.
RFC6265 is lax in it's specification of the `Set-Cookie` header and permits a 2-digit day of month.
See: https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html
See: https://tools.ietf.org/html/rfc1123#page-55
See: https://tools.ietf.org/html/rfc6265#section-5.1.1
Modifications:
- Update `DateFormatter` to correctly implement RFC 2616 headers
Result:
```
Date: Sun, 06 Nov 1994 08:49:37 GMT
Expires: Sun, 06 Nov 1994 08:49:37 GMT
Set-Cookie: id=a3fWa; Expires=Sun, 06 Nov 1994 08:49:37 GMT
```
Motivation:
`io.netty.channel.ChannelHandler` is never used in JsonObjectDecoder.java.
Modification:
Just remove this unused import.
Result:
Make the JsonObjectDecoder.java's imports simple and clean.
Motivation:
To ensure we always recycle the CodecOutputList we should better do it in a finally block
Modifications:
Call CodecOutputList.recycle() in finally
Result:
Less chances of non-recycled lists. Related to https://github.com/netty/netty/issues/10183
Motivation:
In the code example of ReplayingDecoder, an input parameter List<Object> out is missing.
Modification:
Just add this parameter.
Result:
The right doc.
Motivation:
Since the LZF support non-compress and compress format, we can let LzfEncoder support length aware ability. It can let the user control compress.
Modification:
When the data length over compressThreshold, LzfEncoder use compress format to compress data. Otherwise, only use non-compress format. Whatever compress format the encoder use, the LzfDecoder can decompress data well.
Result:
Gives users control over compression capabilities
Motivation:
The Snappy crc32c checksum produced by SnappyFrameEncoder maybe failed to be validated on other languages snappy decoder, such as golang/snappy.
Modification:
- make the 4-byte cast later after the mask operation. Because whether retaining the higher 4-7 bytes in a long java type will make difference in (checksum >> 15 | checksum << 17) + 0xa282ead8 result.
Result:
Checksum correctly calculated
Motivation:
It is impossible to know in advance how much memory will be needed to
decompress a stream of bytes that was compressed using the DEFLATE
algorithm. In theory, up to 1032 times the compressed size could be
needed. For untrusted input, an attacker could exploit this to exhaust
the memory pool.
Modifications:
ZlibDecoder and its subclasses now support an optional limit on the size
of the decompressed buffer. By default, if the limit is reached,
decompression stops and a DecompressionException is thrown. Behavior
upon reaching the limit is modifiable by subclasses in case they desire
something else.
Result:
The decompressed buffer can now be limited to a configurable size, thus
mitigating the possibility of memory pool exhaustion.
Motivation:
We should close encoder when `LzfEncoder` was removed from pipeline.
Modification:
call `encoder.close` when `handlerRemoved` triggered.
Result:
Close encoder to release internal buffer.
Motivation
This PR is a reduced-scope replacement for #8931. It doesn't include the
changes related to how/when discarding read bytes is done, which we plan
to address in subsequent updates.
Modifications
- Avoid copying bytes in COMPOSITE_CUMULATOR in all cases, performing a
shallow copy where necessary; also guard against (unusual) case where
input buffer is composite with writer index != capacity
- Ensure we don't pass a non-contiguous buffer when MERGE_CUMULATOR is
used
- Manually inline some calls to ByteBuf#writeBytes(...) to eliminate
redundant checks and reduce stack depth
Also includes prior minor review comments from @trustin
Result
More correct handling of merge/composite cases and
more efficient handling of composite case.
Motivation:
ByteToMessageDecoder's default MERGE_CUMULATOR will allocate a new buffer and
copy if the refCnt() of the cumulation is > 1. However this is overly
conservative because we maybe able to avoid allocate/copy if the current
cumulation can accommodate the input buffer without a reallocation. Also when the
reallocation and copy does occur the new buffer is sized just large enough to
accommodate the current the current amount of data. If some data remains in the
cumulation after decode this will require a new allocation/copy when more data
arrives.
Modifications:
- Use maxFastWritableBytes to avoid allocation/copy if the current buffer can
accommodate the input data without a reallocation operation.
- Use ByteBufAllocator#calculateNewCapacity(..) to get the size of the buffer
when a reallocation/copy operation is necessary.
Result:
ByteToMessageDecoder MERGE_CUMULATOR won't allocate/copy if the cumulation
buffer can accommodate data without a reallocation, and when a reallocation
occurs we are more likely to leave additional space for future data in an effort
to reduce overall reallocations.
Motivation:
The buffer which the decoder allocates for the expansion can be
leaked if there is a subsequent issue writing to it.
Modifications:
The error handling has been improved so that the new buffer always
is released on failure in the expand.
Result:
The decoder will not leak in this scenario any more.
Fixes: https://github.com/netty/netty/issues/9812
Motivation:
Data flowing in from the decoder flows out in sequence，Whether decoder removed or not.
Modification:
fire data in out and clear out when hander removed
before call method handlerRemoved(ctx)
Result:
Fixes#9668 .
Motivation:
At the moment we do a ByteBuf.readBytes(...) on removal of the ByteToMessageDecoder if there are any bytes left and forward the returned ByteBuf to the next handler in the pipeline. This is not really needed as we can just forward the cumulation buffer directly and so eliminate the extra memory copy
Modifications:
Just forward the cumulation buffer directly on removal of the ByteToMessageDecoder
Result:
Less memory copies
Motivation:
We can use the `@SuppressJava6Requirement` annotation to be more precise about when we use Java6+ APIs. This helps us to ensure we always protect these places.
Modifications:
Make use of `@SuppressJava6Requirement` explicit
Result:
Fixes https://github.com/netty/netty/issues/2509.
Motivation:
In the current implementation of Base64 decoder an invalid
character `\u00BD` treated as `=`.
Also character `\u007F` leads to ArrayIndexOutOfBoundsException.
Modification:
Explicitly checks that all input bytes are ASCII characters
(greater than zero). Fix `decodabet` tables.
Result:
Correctly validation input bytes in Base64 decoder.
Motivation:
There is some manual coping of elements of Collections which can be replaced by Collections.addAll(...) and also some unnecessary semicolons.
Modifications:
- Simplify branches
- Use Collections.addAll
- Code cleanup
Result:
Code cleanup
Motivation:
ByteToMessageDecoder only looks at the last channelRead() in the batch
of channelRead()-s when determining whether or not it should call
ChannelHandlerContext#read() to consume more data when !isAutoRead. This
will lead to read() calls issued unnecessaily and unprompted if the very
last channelRead() didn't result in at least one decoded message, even
if there have been messages decoded from other channelRead()-s in the
current batch.
Modifications:
Track decode outcomes for the entire batch of channelRead() calls and
only issue a read in BTMD if the entire batch of channelRead() calls
yielded no complete messages.
Result:
ByteToMessageDecoder will no longer overread when the very last read
yielded no message, but the batch of reads did.
Motivation:
Lz4FrameEncoder and Lz4FrameDecoder in their default configuration use
an extremely inefficient way to checksum direct byte buffers. In
particular, for every byte checksummed, a single-element byte array is
being allocated and a JNI cal is made, which in some internal testing
makes a 25x difference in total throughput and allocates *a lot* of
garbage.
Modifications:
Lz4XXHash32, an implementation of ByteBufChecksum specifically for use
by Lz4FrameEncoder and Lz4FrameDecoder, is introduced. It utilises
xxHash32 block API which provides a hash() method that accepts a
ByteBuffer as an argument. Lz4FrameEncoder and Lz4FrameDecoder are
modified to use this implementation by default.
Result:
Lz4FrameEncoder and Lz4FrameDecoder perform well again when operating
on direct byte buffers with default checksum configuration; a public
implementation is provided for those who need to override the seed.
Motivation:
ReflectiveByteBufChecksum#update(buf, off, len) ignores provided offset
and length arguments when operating on direct buffers, leading to wrong
byte sequences being checksummed and ultimately incorrect checksum
values (unless checksumming the entire buffer).
Modifications:
Use the provided offset and length arguments to get the correct nio
buffer to checksum; add test coverage exercising the four meaningfully
different offset and length combinations.
Result:
Offset and length are respected and a correct checksum gets calculated;
simple unit test should prevent regressions in the future.
Motivation:
Because of a simple bug in ByteBufChecksum#updateByteBuffer(Checksum),
ReflectiveByteBufChecksum is never used for CRC32 and Adler32, resulting
in direct ByteBuffers being checksummed byte by byte, which is
undesriable.
Modification:
Fix ByteBufChecksum#updateByteBuffer(Checksum) method to pass the
correct argument to Method#invoke(Checksum, ByteBuffer).
Result:
ReflectiveByteBufChecksum will now be used for Adler32 and CRC32 on
Java8+ and direct ByteBuffers will no longer be checksummed on slow
byte-by-byte basis.
Motivation:
It is valid to use null as sender so we should support it when DatagramPacketEncoder checks if it supports the message.
Modifications:
- Add null check
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9199.
Motivation:
At the moment ByteToMessageDecoder always calls fireChannelReadComplete() when the handler is removed from the pipeline and the cumulation buffer is not null. We should only call it when we also call fireChannelRead(...), which only happens if the cumulation buffer is not null and readable.
Modifications:
Only call fireChannelReadComplete() if fireChannelRead(...) is called before during removal of the handler.
Result:
More correct semantics
Motivation:
OOME is occurred by increasing suppressedExceptions because other libraries call Throwable#addSuppressed. As we have no control over what other libraries do we need to ensure this can not lead to OOME.
Modifications:
Only use static instances of the Exceptions if we can either dissable addSuppressed or we run on java6.
Result:
Not possible to OOME because of addSuppressed. Fixes https://github.com/netty/netty/issues/9151.
Motivation:
DefaultHeaders entries maintains two linked lists. 1 for overall insertion order
and 1 for "in bucket" order. DefaultHeaders#valueIterator removal (introduced in 1d9090aab2) only reliably
removes the entry from the overall insertion order, but may not remove from the
bucket unless the element is the first entry.
Modifications:
- DefaultHeaders$ValueIterator should track 2 elements behind the next entry so
that the single linked "in bucket" list can be patched up when removing the
previous entry.
Result:
More correct DefaultHeaders#valueIterator removal.
Motivation:
While iterating values it is often desirable to be able to remove individual
entries. The existing mechanism to do this involves removal of all entries and
conditional re-insertion which is heavy weight in order to remove a single
value.
Modifications:
- DefaultHeaders$ValueIterator supports removal
Result:
It is possible to remove entries while iterating the values in DefaultHeaders.
Motivation:
32563bfcc1 introduced a regression in which we did now not longer discard the messages after we handled an oversized message.
Modifications:
- Do not set aggregating to false after handleOversizedMessage is called
- Adjust unit tests to verify the behaviour is correct again.
Result:
Fixes https://github.com/netty/netty/issues/9007.
Motivation:
PromiseCombiner is not thread-safe and even assumes all added Futures are using the same EventExecutor. This is kind of fragile as we do not enforce this. We need to enforce this contract to ensure it's safe to use and easy to spot concurrency problems.
Modifications:
- Add new contructor to PromiseCombiner that takes an EventExecutor and deprecate the old non-arg constructor.
- Check if methods are called from within the EventExecutor thread and if not fail
- Correctly dispatch on the right EventExecutor if the Future uses a different EventExecutor to eliminate concurrency issues.
Result:
More safe use of PromiseCombiner + enforce correct usage / contract.
Motivation:
Just was looking through code and found 1 interesting place DateFormatter.tryParseMonth that was not very effective, so I decided to optimize it a bit.
Modification:
Changed DateFormatter.tryParseMonth method. Instead of invocation regionMatch() for every month - compare chars one by one.
Result:
DateFormatter.parseHttpDate method performance improved from ~3% to ~15%.
Benchmark (DATE_STRING) Mode Cnt Score Error Units
DateFormatter2Benchmark.parseHttpHeaderDateFormatter Sun, 27 Jan 2016 19:18:46 GMT thrpt 6 4142781.221 ± 82155.002 ops/s
DateFormatter2Benchmark.parseHttpHeaderDateFormatter Sun, 27 Dec 2016 19:18:46 GMT thrpt 6 3781810.558 ± 38679.061 ops/s
DateFormatter2Benchmark.parseHttpHeaderDateFormatterNew Sun, 27 Jan 2016 19:18:46 GMT thrpt 6 4372569.705 ± 30257.537 ops/s
DateFormatter2Benchmark.parseHttpHeaderDateFormatterNew Sun, 27 Dec 2016 19:18:46 GMT thrpt 6 4339785.100 ± 57542.660 ops/s
Motivation
Implementations of MessageAggregator (HttpObjectAggregator in particular) may wish to
selectively aggrerage requests and responses on a case-by-case basis such as for example
only POST requests or only responses of a certain content-type.
Modifications
Adding a flag to MessageAggregator that toggles between true/false depending on if aggregation
is desired for the current message or not.
Result
Fixes#8772
Motivation:
We have a utility method to check for > 0 and >0 arguments. We should use it.
Modification:
use checkPositive/checkPositiveOrZero instead of if statement.
Result:
Re-use utility method.
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:
LineBasedFrameDecoder, JsonObjectDecoder and XmlFrameDecoder upon investigation of the
sourcecode appeared to only support ASCII or UTF-8 input. It is an important characteristic
and ont reflected in any documentation. This could lead to improper usage and bugs.
Modifications:
Javadoc comment is addedd to all three classes to state that implementation is only
compatible with UTF-8 or ASCII input streams and brifly touches on implementaion details.
Result:
The end user of the netty library would not have to study sorcecode to deterime character
encoding limitations for given classes.
Motivation:
We had some typo (most likely caused by copy-and-paste) in the api docs which should be fixed.
Modifications:
Replace encoder by decoder word.
Result:
Correct apidocs.
Motivation:
If the encoder needs to flush more than one outbound message it will
create a new ChannelPromise for all but the last write which will
swallow failures.
Modification:
Use a PromiseCombiner in the case of multiple messages and the parent
promise isn't the `VoidPromise`.
Result:
Intermediate failures are propagated to the original ChannelPromise.
Motivation:
There are currently many more places where this could be used which were
possibly not considered when the method was added.
If https://github.com/netty/netty/pull/8388 is included in its current
form, a number of these places could additionally make use of the same
BYTE_ARRAYS threadlocal.
There's also a couple of adjacent places where an optimistically-pooled
heap buffer is used for temp byte storage which could use the
threadlocal too in preference to allocating a temp heap bytebuf wrapper.
For example
https://github.com/netty/netty/blob/4.1/buffer/src/main/java/io/netty/buffer/ByteBufUtil.java#L1417.
Modifications:
Replace new byte[] with PlatformDependent.allocateUninitializedArray()
where appropriate; make use of ByteBufUtil.getBytes() in some places
which currently perform the equivalent logic, including avoiding copy of
backing array if possible (although would be rare).
Result:
Further potential speed-up with java9+ and appropriate compile flags.
Many of these places could be on latency-sensitive code paths.
