zlib-ng
rapidgzip
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zlib-ng | rapidgzip | |
---|---|---|
13 | 14 | |
1,445 | 317 | |
2.1% | - | |
9.3 | 9.5 | |
5 days ago | 7 days ago | |
C | C++ | |
zlib License | Apache License 2.0 |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
zlib-ng
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Show HN: Pzip- blazing fast concurrent zip archiver and extractor
Please note that allowing for 2% bigger resulting file could mean huge speedup in these circumstances even with the same compression routines, seeing these benchmarks of zlib and zlib-ng for different compression levels:
https://github.com/zlib-ng/zlib-ng/discussions/871
IMO the fair comparison of the real speed improvement brought by a new program is only between the almost identical resulting compressed sizes.
- Intel QuickAssist Technology Zstandard Plugin for Zstandard
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Introducing zune-inflate: The fastest Rust implementation of gzip/Zlib/DEFLATE
It is much faster than miniz_oxide and all other safe-Rust implementations, and consistently beats even Zlib. The performance is roughly on par with zlib-ng - sometimes faster, sometimes slower. It is not (yet) as fast as the original libdeflate in C.
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Zlib Critical Vulnerability
Zlib-ng doesn't contain the same code, but it appears that their equivalent inflate() when used with their inflateGetHeader() implementation was affected by a similar problem: https://github.com/zlib-ng/zlib-ng/pull/1328
Also similarly, most client code will be unaffected because `state->head` will be NULL, because they (most client code) won't have used inflateGetHeader() at all.
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Git’s database internals II: commit history queries
I wonder if zlib-ng would make a difference, since it has a lot of optimizations for modern hardware.
https://github.com/zlib-ng/zlib-ng/discussions/871
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Computing Adler32 Checksums at 41 GB/s
zlib-ng also has adler32 implementations optimized for various architectures: https://github.com/zlib-ng/zlib-ng
Might be interesting to benchmark their implementation too to see how it compares.
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Convenient CPU feature detection and dispatch in the Magnum Engine
zlib-ng: https://github.com/zlib-ng/zlib-ng/blob/develop/functable.c
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games-emulation/dolphin-9999 is failing to build because devs switched to minizip-ng and zlib uses minizip. I'm not sure how to get it to build now, details in post.
(2) There are many packages that rely upon zlib and minizip and switching those underlying dependencies is easier said than done. We can't drop zlib completely and switch: "The idea of zlib-ng is not to replace zlib, but to co-exist as a drop-in replacement with a lower threshold for code change." - https://github.com/zlib-ng/zlib-ng
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Re: Zlib memory corruption on deflate (i.e. compress)
There are already active zlib forks (e.g. https://github.com/zlib-ng/zlib-ng), the problem is with having people move to them. It takes a lot of effort to move mindshare from the original version to a fork, there's some historical examples of it happening, but not a ton.
rapidgzip
- Show HN: Rapidgzip – Parallel Gzip Decompressing with 10 GB/S
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Ebiggers/libdeflate: Heavily optimized DEFLATE/zlib/gzip library
I also did benchmarks with zlib and libarchivemount via their library interface here [0]. It has been a while that I have run them, so I forgot. Unfortunately, I did not add libdeflate.
[0] https://github.com/mxmlnkn/rapidgzip/blob/master/src/benchma...
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Rapidgzip – Parallel Decompression and Seeking in Gzip (Knespel, Brunst – 2023) [pdf]
Hi, author here.
You are right in the index being the easy-mode. Over the years there have been lots of implementations trying to add an index like that to the gzip metadata itself or as a sidecar file, with bgzip probably being the most known one. None of them really did stick, hence the necessity for some generic multi-threaded decompressor. A probably incomplete list of such implementations can be found in this issue: https://github.com/mxmlnkn/rapidgzip/issues/8
The index makes it so easy that I can simply delegate decompression to zlib. And since paper publication I've actually improved upon this by delegating to ISA-l / igzip instead, which is twice as fast. This is already in the 0.8.0 release.
As derived from table 1, the false positive rate is 1 Tbit / 202 = 5 Gbit or 625 MB for deflate blocks with dynamic Huffman code. For non-compressed blocks, the false positive rate is roughly one per 500 KB, however non-compressed blocks can basically be memcpied or skipped over and then the next deflate header can be checked without much latency. On the other hand, for dynamic blocks, the whole block needs to be decompressed first to find the next one. So the much higher false positive rate for non-compressed blocks doesn't introduce that much overhead.
I have some profiling built into rapidgzip, which is printed with -v, e.g., rapidgzip -v -d -o /dev/null 20xsilesia.tar.gz :
Time spent in block finder : 0.227751 s
- Intel QuickAssist Technology Zstandard Plugin for Zstandard
- Tool and Library for Parallel Gzip Decompression and Random Access
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Pigz: Parallel gzip for modern multi-processor, multi-core machines
I have not only implemented parallel decompression but also random access to offsets in the stream with https://github.com/mxmlnkn/pragzip I did some benchmarks on some really beefy machines with 128 cores and was able to reach almost 20 GB/s decompression bandwidth. The single-core decoder has lots of potential for optimization because I had to write it from scratch, though.
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Parquet: More than just “Turbo CSV”
Decompression of arbitrary gzip files can be parallelized with pragzip: https://github.com/mxmlnkn/pragzip
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The Cost of Exception Handling
At the very least you are duplicating logic without the exception. The check for eof has to be done implicitly anyway inside read because it has to fill the bit buffer with data from the byte buffer or the byte buffer with data from the file. And if both fail, then we already know the result of eof, so no need to duplicate checking for eof in the outer read calling loop.
Here is the full commit with ad-hoc benchmark results in the commit message:
https://github.com/mxmlnkn/pragzip/commit/0b1af498377838c30f...
and here the benchmarks I ran at that time:
https://github.com/mxmlnkn/pragzip/blob/0b1af498377838c30fea...
As you can see, it's part of my random-seekable multi-threaded gzip and bzip2 parallel decompression libraries.
What you can also see in the commit message is that it wasn't a 50% time reduction but a 50% bandwidth increase, which would translate to a 30% time reduction. It seems I remembered that partly wrong. But it still was a significant optimization for me.
- How Much Faster Is Making a Tar Archive Without Gzip?
- Show HN: Thread-Parallel Decompression and Random Access to Gzip Files (Pragzip)
What are some alternatives?
zstd - Zstandard - Fast real-time compression algorithm
QATzip - Compression Library accelerated by Intel® QuickAssist Technology
ZLib - A massively spiffy yet delicately unobtrusive compression library.
pigz - A parallel implementation of gzip for modern multi-processor, multi-core machines.
Minizip-ng - Fork of the popular zip manipulation library found in the zlib distribution.
nvcomp - Repository for nvCOMP docs and examples. nvCOMP is a library for fast lossless compression/decompression on the GPU that can be downloaded from https://developer.nvidia.com/nvcomp.
libdeflate - Heavily optimized library for DEFLATE/zlib/gzip compression and decompression
parquet-format - Apache Parquet
brotli - Brotli compression format
DirectStorage - DirectStorage for Windows is an API that allows game developers to unlock the full potential of high speed NVMe drives for loading game assets.
uzlib - Radically unbloated DEFLATE/zlib/gzip compression/decompression library. Can decompress any gzip/zlib data, and offers simplified compressor which produces gzip-compatible output, while requiring much less resources (and providing less compression ratio of course).
pixz - Parallel, indexed xz compressor