Motivation:
As we have java8 as a minimum target we can use MethodHandles. We should do so when we expect to have a method called multiple times.
Modifications:
- Replace usage of reflection with MethodHandles where it makes sense
- Remove some code which was there to support java < 8
Result:
Faster code
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:
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 lambdas now as we use Java8.
Modification:
use lambda function for all package, #8751 only migrate transport package.
Result:
Code cleanup.
Motivation:
As netty 4.x supported Java 6 we had various if statements to check for java versions < 8. We can remove these now.
Modification:
Remove unnecessary if statements that check for java versions < 8.
Result:
Cleanup code.
Motivation:
We should try to minimize memory copies whenever possible.
Modifications:
- Refactor ByteBufChecksum to work with heap and direct ByteBuf always
- Remove memory copy in Snappy by let Crc32c extend ByteBufChecksum
Result:
Less memory copies when using Snappy
Motivation:
When the user constructs Lz4FrameDecoder with a Checksum implementation like CRC32 or Adler32 and uses Java8 we can directly use a ByteBuffer to do the checksum work. This way we can eliminate memory copies.
Modifications:
Detect if ByteBuffer can be used for checksum work and if so reduce memory copies.
Result:
Less memory copies when using JDK8
Norman Maurer
Aleksey Yeschenko
Aleksey Yeschenko
田欧
kezhenxu94
Nikolay Fedorovskikh