zlib-ng VS LZ4

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.

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.

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.

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

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.

zlib-ng: https://github.com/zlib-ng/zlib-ng/blob/develop/functable.c

(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

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.

LZ4 is a bit more complicated, but seems faster: https://github.com/lz4/lz4/blob/dev/doc/lz4_Block_format.md

According to these https://github.com/lz4/lz4 values you need around ten (10) quite modern cores in parallel to accomplish around 8GB/s.

The popular NoSQL database Cassandra utilizes a compression algorithm called LZ4 to reduce the footprint of data at rest. LZ4 is characterized by very fast compression speed at the cost of a higher compression ratio. This is a design choice that allows Cassandra to maintain high write throughput while also benefiting from compression in some capacity.

Yeah, sure, when you have monster core counts. on regular systems, not so much, here's from their own github page. it achieves, eh, 5GB/s on memory to memory transfers, i.e. best case scenario. so, uh, no? i'm not even sure it's any better than the CPU decompressor one Nvidia used.

> The downside of lz4 is that it can’t be configured to run at higher & slower compression ratios.

lz4 has some level of configurability? https://github.com/lz4/lz4/blob/v1.9.4/lib/lz4frame.h#L194

There's also LZ4_HC.

Since nobody mentioned it, I'll add lz4 (https://github.com/lz4/lz4).

Get your bootloader unlocked via Download mode and then obtain your stock firmware, preferably for your current region https://samfw.com (Download mode: CARRIER_CODE). Get the boot image from AP with 7zip, unpack from LZ4 with https://github.com/lz4/lz4/releases (drag and drop), patch with Magisk https://github.com/topjohnwu/magisk/releases/latest, grab the new image, name it "boot.img" and pack it into a .tar with 7zip and flash to AP with odin https://odindownload.com

After some investigations and experiments, I found out that it was the PNG compression (well, decompression I should say) that took a while. So I've made some experiments using the LZ4 compression library, which is focused on decompression speed, and it turned out to be an excellent solution!

Root with magisk: whether you use OneUI ≤3 or 4, patch the specific image needed for it (pre 4: boot, after 4: recovery) and flash it to the device. Boot it and enjoy root. https://github.com/lz4/lz4/releases can help extracting it from the AP tarball.