libdeflate VS zstd

zune-inflate is a port of libdeflate to safe Rust.

> The QOI benchmarks shows it only lagging a small bit behind PNG in compression ratio, while performing much faster (multiples) in both encoding and decoding.

Presumably that’s with stock libpng, which uses zlib. I wonder if anyone tried patching it to use the substantially faster (on x86) libdeflate[1] instead? It doesn’t do streaming, but you shouldn’t really need it for PNG textures.

[1] https://github.com/ebiggers/libdeflate

Eric biggers libdeflate https://github.com/ebiggers/libdeflate/blob/master/lib/deflate_decompress.c

Note that libdeflate has used essentially the same method since 2016 (https://github.com/ebiggers/libdeflate/blob/v0.4/lib/adler32...), though I recently switched it to use a slightly different method (https://github.com/ebiggers/libdeflate/blob/v1.12/lib/x86/ad...) that performs more consistently across different families of x86 CPUs.

Going away from Zlib proper but staying with its format, there’s libdeflate[1], an implementation that’s substantially faster on modern machines but can’t stream, and of course Zopfli[2], a glacially slow compressor that’s somewhat better (and occasionally much more so).

[1] https://github.com/ebiggers/libdeflate

[2] https://github.com/google/zopfli

This VFS will read a sqlite file after it has been compressed using [zstd seekable format](https://github.com/facebook/zstd/blob/dev/contrib/seekable_f...). Built to support read-only databases for full-text search. Benchmarks are provided in README.

Of course, you may get different results with another dataset.

gzip (zlib -6) [ratio=32%] [compr=35Mo/s] [dec=407Mo/s]

zstd (zstd -2) [ratio=32%] [compr=356Mo/s] [dec=1067Mo/s]

NB1: The default for zstd is -3, but the table only had -2. The difference is probably small. The range is 1-22 for zstd and 1-9 for gzip.

NB2: The default program for gzip (at least with Debian) is the executable from zlib. With my workflows, libdeflate-gzip iscompatible and noticably faster.

NB3: This benchmark is 2 years old. The latest releases of zstd are much better, see https://github.com/facebook/zstd/releases

For a high compression, according to this benchmark xz can do slightly better, if you're willing to pay a 10× penalty on decompression.

xz -9 [ratio=23%] [compr=2.6Mo/s] [dec=88Mo/s]

zstd -9 [ratio=23%] [compr=2.6Mo/s] [dec=88Mo/s]

Compression, synchronization and backup systems often use rolling hash to implement "content-defined chunking", an effective form of deduplication.

In optimized implementations, Rabin-Karp is likely to be the bottleneck. See for instance https://github.com/facebook/zstd/pull/2483 which replaces a Rabin-Karp variant by a >2x faster Gear-Hashing.

Get the data https://publicdistst.blob.core.windows.net/data/root.tar.zst magnet:?xt=urn:btih:84931cd80409ba6331f2fcfbe64ba64d4381aec5&dn=root.tar.zst How to extract https://github.com/facebook/zstd Linux (debian): `sudo apt install zstd` ``` tar -I 'zstd -d -T0' -xvf root.tar.zst ```

I've done that experiment with zstd before.

https://github.com/facebook/zstd/blob/dev/programs/zstd.1.md...

Not sure about brotli though.

If you want this functionality in zstd itself, check this out: https://github.com/facebook/zstd/pull/2349