netty5/codec-http
Frédéric Brégier 42dc696c6c Fix behavior of HttpPostMultipartRequestDecoder for Memory based Factory (#11145)
Motivation:
When Memory based Factory is used, if the first chunk starts with Line Break, the HttpData
is not filled with the current available buffer if the delimiter is not found yet, while it may
add some.

Fix JavaDoc to note potential wrong usage of content() or getByteBuf() if HttpDatais has
a huge content with the risk of Out Of Memory Exception.

Fix JavaDoc to explain how to release properly the Factory, whatever it is in Memory,
Disk or Mixed mode.

Fix issue #11143

Modifications:
First, when the delimiter is not found, instead of searching Line Break from readerIndex(), we should search
from readerIndex() + readableBytes() - delimiter size, since this is the only part where usefull
Line Break could be searched for, except if readableBytes is less than delimiter size (then we search from
readerIndex).

Second, when a Memory HttpData is created, it should be assigned an empty buffer to be
consistent with the other implementations (Disk or Mixed mode).
We cannot change the default behavior of the content() or getByteBuf() of the Memory based HttpData
since the ByteBuf is supposed to be null when released, but not empty.
When a new ByteBuf is added, one more check verifies if the current ByteBuf is empty, and if so, it
is released and replaced by the new one, without creating a new CompositeByteBuf.

Result:
In the tests testBIgFileUploadDelimiterInMiddleChunkDecoderMemoryFactory and related for other modes,
the buffers are starting with a CRLF.
When we offer only the prefix part of the multipart (no data at all), the current Partial HttpData has
an empty buffer.
The first time we offer the data starting with CRLF to the decoder, it now
has a correct current Partial HttpData with a buffer not empty.

The Benchmark was re-run against this new version.

Old Benchmark                                                                       Mode  Cnt  Score   Error   Units
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigAdvancedLevel   thrpt    6  4,037 ± 0,358  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigDisabledLevel   thrpt    6  4,226 ± 0,471  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigParanoidLevel   thrpt    6  0,875 ± 0,029  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigSimpleLevel     thrpt    6  4,346 ± 0,275  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighAdvancedLevel  thrpt    6  2,044 ± 0,020  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighDisabledLevel  thrpt    6  2,278 ± 0,159  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighParanoidLevel  thrpt    6  0,174 ± 0,004  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighSimpleLevel    thrpt    6  2,370 ± 0,065  ops/ms

New Benchmark                                                                       Mode  Cnt  Score   Error   Units
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigAdvancedLevel   thrpt    6  5,604 ± 0,415  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigDisabledLevel   thrpt    6  6,058 ± 0,111  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigParanoidLevel   thrpt    6  0,914 ± 0,031  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderBigSimpleLevel     thrpt    6  6,053 ± 0,051  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighAdvancedLevel  thrpt    6  2,636 ± 0,141  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighDisabledLevel  thrpt    6  3,033 ± 0,181  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighParanoidLevel  thrpt    6  0,178 ± 0,006  ops/ms
HttpPostMultipartRequestDecoderBenchmark.multipartRequestDecoderHighSimpleLevel    thrpt    6  2,859 ± 0,189  ops/ms

So +20 to +40% improvement due to not searching for CRLF/LF into the full buffer when no delimiter is found,
but only from the end and delimiter size + 2 (CRLF).
2021-04-16 11:05:09 +02:00
..
src Fix behavior of HttpPostMultipartRequestDecoder for Memory based Factory (#11145) 2021-04-16 11:05:09 +02:00
pom.xml Use http in xmlns URIs to make maven release plugin happy again (#10788) 2020-11-10 10:51:05 +01:00