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:
SnappyFrameDecoderTest has a few tests which fail to close the EmbeddedChannel
and therefore may leak ByteBuf objects.
Modifications:
- Make sure EmbeddedChannel#finishAndReleaseAll() is called in all tests
Result:
No more leaks from SnappyFrameDecoderTest.
Motivation:
We did not correctly close the `EmbeddedChannel` which would lead to not have `handlerRemoved(...)` called. This can lead to leaks. Beside this we also did not correctly consume produced data which could also show up as a leak.
Modifications:
- Always call `EmbeddedChannel.finish()`
- Ensure we consume all produced data and release it
Result:
No more leaks in test. This showed up in https://github.com/netty/netty/pull/9850#issuecomment-562504863.
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:
Netty homepage(netty.io) serves both "http" and "https".
It's recommended to use https than http.
Modification:
I changed from "http://netty.io" to "https://netty.io"
Result:
No effects.
Motivation:
There are is some unnecessary code (like toString() calls) which can be cleaned up.
Modifications:
- Remove not needed toString() calls
- Simplify subString(...) calls
- Remove some explicit casts when not needed.
Result:
Cleaner code
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
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:
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.
