#bzip2
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studio8502.ca
Adding something Finder on macOS can't do on its own: handle creating and extracting tarballs compressed with gzip, bzip2, and xz.
November 4, 2026 at 10:18 PM
permutans.bsky.social
🆕 mibz2 blog ⠶Reading the BWT's runs off bzip2's move-to-front codes lmmx.github.io/mibz2/blog/2...
lmmx.github.io
November 8, 2026 at 5:33 PM
permutans.bsky.social
🆕 mibz2 blog ⠶ A new way back from the BWT lmmx.github.io/mibz2/blog/2...
A new way back from the BWT
An experimental mibz2 kernel rebuilds bzip2 text without a row-by-row walk, from reusable word rules that form the block's Lyndon tree.
lmmx.github.io
November 10, 2026 at 3:51 PM
onedroid.ai
A swarm cutting instructions from a bzip2 decoder, reviewed by agents inside the same loop. Who checks the decoded bytes still match reference bzip2 on files none of them picked? mibz2 is public: say yes and we'll point a separate tester at it and send you what it finds.
November 4, 2026 at 4:14 PM
permutans.bsky.social
🆕 mibz2 blog ⠶ Call on mibz2: cutting instructions from bzip2 decoding with an autonomous swarm lmmx.github.io/mibz2/blog/2...
Call on mibz2: cutting instructions from bzip2 decoding with an autonomous swarm
Each of four agents does one part of the research. A GitHub doorbell lets them hand work to each other directly, without me acting as their message bus.
lmmx.github.io
November 4, 2026 at 3:43 PM
permutans.bsky.social
🆕 mibz2 blog ⠶ Building a smaller bzip2 decoding table: from 49 instructions to 12 lmmx.github.io/mibz2/blog/2...
Building a smaller bzip2 decoding table: from 49 instructions to 12
Writing a cheap placeholder for each row, and finishing each 30-row group once, shrank the inner loop. It still builds too slowly.
lmmx.github.io
November 4, 2026 at 9:35 AM
tweakers.net.web.brid.gy
Software-update - 7-Zip 26.06
Versie 26.06 van het open source archiveringsprogramma 7-Zip is uitgebracht, een stabiele uitgave. Dit programma kan overweg met een groot aantal compressieformaten, waaronder ZIP, CAB, RAR, ARJ, LZH, CHM, gzip, bzip2, z, tar, cpio, RPM, deb en uiteraard het zelfontwikkelde 7z. Verder is de software in staat om ISO-bestanden en NSIS-installatiepakketten te openen. In deze uitgave zijn de volgende verbeteringen aangebracht: What's new in 7-Zip 26.06:
tweakers.net
November 7, 2026 at 8:53 PM
portableapps.com.web.brid.gy
7-Zip Portable 26.05 (file archiver) Released
A new version of 7-Zip Portable has been released. It's the popular 7-Zip packaged as a portable app, so you can take your file archiver with you and work with your compressed 7z, ZIP, GZIP, BZIP2, TAR, RAR files and more on the go. It's packaged in PortableApps.com Format for easy use from any portable device and integration with the PortableApps.com Platform. And it's open source and completely free. _Update automatically or install from the portable app store in the PortableApps.com Platform._
portableapps.com
November 6, 2026 at 12:04 AM
permutans.bsky.social
📄 Weißenberger & Schmidt (2024) Massively Parallel Inverse Block-sorting Transforms for bzip2 Decompression on GPUs dl.acm.org/doi/10.1145/...
bzip2gpu github.com/weissenberge...
Massively Parallel Inverse Block-sorting Transforms for bzip2 Decompression on GPUs | Proceedings of the 53rd International Conference on Parallel Processing
dl.acm.org
October 30, 2026 at 8:12 AM
permutans.bsky.social
mibz2: a high-performance bz2 decoding library built around memory-level parallelism lmmx.github.io/mibz2/

Speeds up bzip2 decoding by interleaving independent inverse-BWT traversals, keeping multiple memory accesses in flight, plus SIMD and block-level parallelism boosters 💫
Screenshot of the mibz2 documentation homepage, featuring a large translucent 3D sculpture of three interlocking rectangular loops in coral, blue and mint green. Beside it, the heading “mibz2” and subtitle “A bzip2 decoder built for memory-level parallelism.” Below are details of its interleaved inverse-BWT traversal, correctness checks and portable SIMD support.
October 27, 2026 at 1:30 PM
apt-get-gnu.bsky.social
WinRAR Version 7.30 beta 2
and Windows for ARM ARM64 version will also be released.

This release mainly focuses on security fixes.

Thanks RARLAB

www.rarlab.com/download.htm
WinRAR archiver, a powerful tool to process RAR and ZIP files
WinRAR is a Windows data compression tool that focuses on the RAR and ZIP data compression formats for all Windows users. Supports RAR, ZIP, CAB, ARJ, LZH, TAR, GZip, UUE, ISO, BZIP2, Z and 7-Zip
www.rarlab.com
October 28, 2026 at 5:16 PM
network.dongzhim.in.ap.brid.gy
要建一个`package.use`

app-alternatives/awk gawk
app-alternatives/lex flex
app-alternatives/yacc bison
app-alternatives/tar gnu
app-alternatives/gzip reference
app-alternatives/bzip2 reference
October 28, 2026 at 6:09 AM
permutans.bsky.social
Counterintuitive approach to perf hunting: look for where the CPU is waiting, not (just) where it is working

Claude came up with a trick to create a bz2 decoder 1.76× as fast as lbzip2 via memory-level parallelism (had identified "memory-latency bound" & then rolled its own PMU measurements)
Screenshot of a technical explanation of how a faster bzip2 decoder was developed. It describes the bottleneck in reversing the Burrows–Wheeler transform: approximately 900,000 dependent memory accesses that leave the CPU waiting for data. By following multiple independent chains concurrently, reversal cost fell from 28.5 cycles per byte with one chain to 4.4 with 16 chains, a 6.5× speedup for that operation. The decoder combines 12 concurrent chains with AVX2 and carry-less multiplication, achieving 1.76× faster decompression than lbzip2, with byte-identical output and verified checksums. Screenshot continuing the explanation of the bzip2 decoder optimisation. Interleaving whole blocks initially achieved only 1.03–1.27× speedup because their lookup tables exceeded cache capacity. Instead, the decoder creates independent chains within a single block by selecting 256 random segment starts, processing 12 chains concurrently and reassembling the segments in order. This reduced reversal cost from 31 to approximately 14 cycles per byte. Further SIMD optimisations accelerated CRC calculation, run-length decoding and move-to-front operations. Combined, the optimisations reduced decompression cost from 42.7 to 24.3 cycles per byte.
October 27, 2026 at 6:34 AM
permutans.bsky.social
mibz2 now faster than several alternatives on all samples (libsais TBC), barring repetition-oriented corpora [onebyte, runs] where interleaved inverse BWT traversal chains become unnecessary overhead lmmx.github.io/mibz2/benchm...
Screenshot of the mibz2 documentation’s “Alternatives” benchmark chart, comparing bzip2 decoders across seven datasets: Wikidata, onebyte, pattern, random, records, runs, and text. The chart shows wall-time ratios relative to mibz2 using four threads, on a logarithmic scale with 95% confidence intervals. Values above 1× indicate that mibz2 is faster. On Wikidata, mibz2 outperforms every alternative, including pbz2 (1.45×), lbzip2 (2.12×), and indexed_bzip2 (2.71×). The only alternatives faster than mibz2 are pbz2 on the highly repetitive onebyte (0.76×) and runs (0.60×) datasets. Controls allow switching between wall time, CPU time, peak memory usage, and thread counts.
October 27, 2026 at 5:40 PM
permutans.bsky.social
Common ordinary language philosophy W
Screenshot of a ChatGPT response titled “My proposed goal structure,” presenting two goals for the mibz2 project. Goal A — A published, usable mibz2 library focuses on an independent repository, trustworthy Rust and Python packages, streaming APIs, correctness tests, documentation, journals, release infrastructure, and integration with wikidata-pq. It emphasizes publishing early rather than waiting for all infrastructure to be finished. Goal B — A measured, ambitious performance advance focuses on benchmarking, profiling, exploring optimisation techniques, releasing the best-known implementation, and preserving a complete experimental record. The text describes a decisive performance lead as an ambition, while allowing the campaign to end without achieving one. It concludes that Goal A produces a usable library, while Goal B produces an experimentally improved version, and neither should block the other. Screenshot of a Claude conversation headed “The two /goal commands.” Claude explains that the commands are ChatGPT’s drafts with factual corrections, preserving the user’s intentions, and provides a link to a saved Markdown file. Below, a large code block displays the first /goal command, specifying the finished state of mibz2: an independently published Rust/Python bzip2 decoder with preserved Git history, verified correctness, streaming APIs, portable SIMD acceleration, documentation, CI, release automation, and development journals. The visible text also begins sections titled “NEGOTIABLE” and “NOT AIMED AT.”
October 27, 2026 at 10:09 AM
euvd-bot.bsky.social
🚨 EUVD-2026-109410
📊 7.2/10
🏢 ImageMagick

📝 ImageMagick before 6.9.13-58 and 7.x before 7.1.2-33 contains a stack-based buffer overflow in the handling of bzip2 compressed images. Attackers ca...

🔗 https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-109410

#cybersecurity #infosec #cve #euvd
October 25, 2026 at 2:07 PM
permutans.bsky.social
tl;dr ordered inputs = free perf
Screenshot of a performance analysis headed “🐋 🐋 🐋 🐋 🐋 THIS is a big fish.” It describes evidence that Wikidata’s 103 GB compressed dump contains eight sequential shards, with entity assignment predicted by a SHA-1 rule, nearly ascending IDs, and recoverable bzip2 blocks. A table summarises findings from remote sampling of over 100,000 IDs. A blue bar chart compares modelled full-release processing times at 7 MB/s upload: 12h01m currently, 7h21m with progressive finalisation, and 6h50m with smaller output parts. Green figures highlight potential savings of 4h40m in elapsed time and approximately 105 GB in peak disk usage. The text explains that progressive finalisation could eliminate the need to create, upload, download and reprocess intermediate group files. All projected savings are explicitly labelled as modelled, not measured full-release results.
October 26, 2026 at 9:44 AM
killercup.de
github.com/Softleif/bz2... seems to have worked nicely :) added a bunch of tooling to keep it in check but haven't tried it in the real software
GitHub - Softleif/bz2ngrs: Fast bzip2 decompression in Rust: one call decodes a whole stream from a byte slice into a buffer.
Fast bzip2 decompression in Rust: one call decodes a whole stream from a byte slice into a buffer. - Softleif/bz2ngrs
github.com
October 14, 2026 at 6:05 PM
euvd-bot.bsky.social
🚨 EUVD-2019-4478
📊 9.8/10

📝 BZ2_decompress in decompress.c in bzip2 through 1.0.6 has an out-of-bounds write when there are many selectors.

🔗 https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-4478

#cybersecurity #infosec #cve #euvd
October 14, 2026 at 8:03 AM
tfenne.bsky.social
It honors bzip2's memory contracts, produces identical output unless input (at block scale) is entirely repetitive (i.e. multiple valid minimal rotations), and has been subjected to dozens of CPU-hours of fuzz testing!
October 13, 2026 at 10:29 PM
tfenne.bsky.social
I realize bzip2 isn't the most in-vogue compression these days, but part of that is that it's so slow. Over the space of about a week, I was able to get Claude to build a drop-in replacement that is substantially faster. Drop-in in the way zlib-ng is for zlib - no recompile, just swap the library.
October 13, 2026 at 10:29 PM
tbone.se
🥩🥩Mr T-Bone tip ✨ Chef's pick · Community!🥩🥩

Need a handy PowerShell trick for archives? 📦 This community post shows how PSCompression can create and extract ZIP, tar, RAR, gzip, bzip2 and more, making file wrangling way easier. Nice one, Harm Veenstra 🙌
👉👉 tip.tbone.se/pqgY80
Image
October 12, 2026 at 7:05 AM
harmveenstra.bsky.social
PowerShell has built-in support for compressing files, but it only supports ZIP files. The PSCompression module supports a lot more with more options, in this blog post I will show you how it works.

#PowerShell #Compression
powershellisfun.com/2026/10/09/u...
PowerShell is fun :)Using the PowerShell PSCompression module to create or extract ZIP, tar, RAR, gzip, bzip2, etc
PowerShell has built-in support for compressing files, but it only supports ZIP files. The PSCompression module supports a lot more with more options, in this blog post I will show you how it works…
powershellisfun.com
October 9, 2026 at 7:15 PM
portableapps.com.web.brid.gy
7-Zip Portable 26.04 (file archiver) Released
A new version of 7-Zip Portable has been released. It's the popular 7-Zip packaged as a portable app, so you can take your file archiver with you and work with your compressed 7z, ZIP, GZIP, BZIP2, TAR, RAR files and more on the go. It's packaged in PortableApps.com Format for easy use from any portable device and integration with the PortableApps.com Platform. And it's open source and completely free. _Update automatically or install from the portable app store in the PortableApps.com Platform._
portableapps.com
October 9, 2026 at 8:23 PM