[dependabot]

Bumps isal from 1.8.0 to 1.9.1.

Release notes

Sourced from isal's releases.

version 1.9.1

• Fix BrokenPipeError when piping python -m isal.igzip into head, less or similar programs.

version 1.9.0

By far most of the work on this release has been done by @​ptweezy. Almost all bug fixes and improvements are their work.

Major changes:

• Updated included ISA-L library to 2.32.1.
• Python 3.10 and PyPy 3.10 are no longer supported. Added support for PyPy 3.12 and Python 3.15.
• Restore PyPy wheel builds.
• Fix builds on macOS with Apple Silicon, which used the portable C code of ISA-L rather than its optimized aarch64 assembly. On an Apple M4, decompression is 1.6 to 3 times faster, CRC-32 is 50 times faster, and Adler-32 is 7 times faster.

Optimizations and features:

• isal_zlib.compressobj supports strategy=Z_FIXED at compression level 0. Level 0 then uses fixed Huffman codes instead of starting each block with a Huffman table of about 110 bytes. This shrinks small flushed writes, such as websocket messages: JSON messages of about 440 bytes, each followed by flush(Z_SYNC_FLUSH), compress to an average of 75 instead of 188 bytes. Blocks of a few KiB or more can be larger: about 5% for JSON and 10% for Python source code at 64 KiB. Other strategies, and Z_FIXED at levels 1 to 3, still give a warning and use the default strategy.
• Speed up import isal.igzip and import isal.igzip_threaded by importing argparse and shutil only when the command line interface runs, and by dropping the multiprocessing import.
• Speed up reading lines from binary igzip files through iteration, readlines(), and readline(). On an Apple M4, reading FASTQ data is 1.13 times faster, and reading lines of a few bytes is 1.5 times faster.
• Speed up each write() call to binary igzip files on CPython. On an AMD Ryzen 7 9800X3D with Python 3.14.8, writing FASTQ data or Python source code one line at a time is 1.1 times faster.
• Speed up many small writes to igzip.IGzipFile on Python 3.12 and later. IGzipFile collects these writes in the write buffer of gzip.GzipFile and compresses them in large chunks, which makes writing lines 1.4 times faster.

Bug fixes:

• Fix zlib streams compressed with a preset dictionary so they can be decoded by standard zlib, including builds linked against older ISA-L releases.
• Fix backward seeking in igzip files by discarding buffered compressed data when rewinding the underlying file.

... (truncated)

Changelog

Sourced from isal's changelog.

version 1.9.1

• Fix BrokenPipeError when piping python -m isal.igzip into head, less or similar programs.

version 1.9.0

By far most of the work on this release has been done by @ptweezy <https://github.com/ptweezy>_. Almost all bug fixes and improvements are their work.

Major changes:

• Updated included ISA-L library to 2.32.1.
• Python 3.10 and PyPy 3.10 are no longer supported. Added support for PyPy 3.12 and Python 3.15.
• Restore PyPy wheel builds.
• Fix builds on macOS with Apple Silicon, which used the portable C code of ISA-L rather than its optimized aarch64 assembly. On an Apple M4, decompression is 1.6 to 3 times faster, CRC-32 is 50 times faster, and Adler-32 is 7 times faster.

Optimizations and features:

• isal_zlib.compressobj supports strategy=Z_FIXED at compression level 0. Level 0 then uses fixed Huffman codes instead of starting each block with a Huffman table of about 110 bytes. This shrinks small flushed writes, such as websocket messages: JSON messages of about 440 bytes, each followed by flush(Z_SYNC_FLUSH), compress to an average of 75 instead of 188 bytes. Blocks of a few KiB or more can be larger: about 5% for JSON and 10% for Python source code at 64 KiB. Other strategies, and Z_FIXED at levels 1 to 3, still give a warning and use the default strategy.
• Speed up import isal.igzip and import isal.igzip_threaded by importing argparse and shutil only when the command line interface runs, and by dropping the multiprocessing import.
• Speed up reading lines from binary igzip files through iteration, readlines(), and readline(). On an Apple M4, reading FASTQ data is 1.13 times faster, and reading lines of a few bytes is 1.5 times faster.
• Speed up each write() call to binary igzip files on CPython. On an AMD Ryzen 7 9800X3D with Python 3.14.8, writing FASTQ data or Python source code one line at a time is 1.1 times faster.
• Speed up many small writes to igzip.IGzipFile on Python 3.12 and later. IGzipFile collects these writes in the write buffer of gzip.GzipFile and compresses them in large chunks, which makes writing lines 1.4 times faster.

Bug fixes:

... (truncated)

Commits

• 2498167 Merge pull request #317 from pycompression/release_1.9.1
• 75d0c6d Set version to 1.9.1
• 4f26169 Merge pull request #315 from pycompression/brokenpipe
• a3f07e3 Fix linting
• 305bc59 Fix BrokenPipeError
• 66a0cc5 Add test for broken pipe
• 6202da6 Merge pull request #314 from pycompression/fixupload
• 33d41a4 Upload with cibw name
• f810849 Use recommended pypa flow for publishing packages
• b6dad52 Ensure twine is installed
• Additional commits viewable in compare view

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[github-code-quality]

Code coverage overview

Languages: Python

Python / code-coverage/pytest

main 1d5df56	dependabot/uv/isal-1... bdd024a	+/-
68%	68%	0%

ℹ️ Calculations represent line coverage. Results may change as calculations are updated.