Lbzip2

Lbzip2 is an open source pthreads-based parallel bunzip2/bzip2 filter, passable to GNU tar with the --use-compress-program option. Unfortunately, the software isn't restricted to regular files on input, nor output.

In other words, Lbzip2 is a SMP-based, parallel and bzip2-compatible compression utility, which features a command-line very similar to the one from the bzip2 utility.

The application uses the Gnulib library to build and test processes, which are managed by the GNU build system.

Lbzip2 strives to be portable by requiring UNIX 98 APIs only, besides an unmodified libbz2. Its main target is UNIX-like systems, including Linux and BSD variants.

What is new in this release:

• Fix performance bug in sequential compressor code
• src/compress.c (do_collect_seq): Release collect semaphore before compressing block. This improves performance a lot.

What is new in version 2.3:

• This version adds a new feature: When decompressing with both --force and --stdout options given, lbzip2 will copy files which are not in bzip2 format, instead of reporting an invalid file format.
• This release also fixes several minor bugs.

What is new in version 2.0:

• In this release, lbzip2 writes a single compressed stream per bz2 file instead of multiple concatenated streams.
• It doesn't decompress streams embedded within trailing garbage.
• It detects and rejects more kinds of invalid bz2 files.
• Relying on the independent bzip2 stack written by the new maintainer, lbzip2-2.0 features significantly improved (de)compression speed and robustness.
• In verbose mode, the compression ratio and progress information is displayed for each file.
• Decompression failures result in more detailed messages now.
• Lbzip2-2.x is licensed under the GPL v3.0 or any later version.

What is new in version 0.17:

• Uninitialized fields were accessed on the stack in a structure assignment expression.
• Theoretically, this might have entailed read accesses to trap representations.
• Since those fields weren't initialized because they weren't used at all in the first place, this portability bug was fixed by introducing a dedicated structure without those fields.

What is new in version 0.16 RC1:

• Features like settable compression block size and working with file operands were implemented.
• lbzip2 can now be considered a multi-threaded, command-line compatible replacement for bzip2 in most situations. Lbzip2 never deletes or overwrites files, however.
• The workaround for an earlier GNU getconf bug was extended to EGLIBC in the large file support build script.
• The development status was degraded to beta.

What is new in version 0.15:

• A bug has been fixed where the single-worker decompressor could theoretically omit to decompress the last part of the compressed input and wrongfully signify premature EOF instead.
• In this release, logically independent buffer sizes are detached from each other.
• Several buffer sizes should be more IO-friendly now.
• The splitterblock size of the multiple-workers decompressor was recalculated; an effort was made to deduce it formally in comments.
• The"malloc_trace.pl" script tracks peak memory usage.
• The documentation was refined.

What is new in version 0.14:

• The single-worker decompressor's multiplexer, while passing back all accrued released input slots to the splitter, wrote out at most one decompressed sub-block per one iteration of its outermost loop. In case of a slowly progressing muxer, this could lead to skyrocketing memory allocation on part of the worker.
• Now the SWD's muxer writes out all accrued decompressed sub-blocks per iteration. The documentation has been updated.
• The build system has received a minuscule portability improvement.

What is new in version 0.13:

• Besides some code cleanup, various portability and other workarounds were introduced to cope with bugs in C libraries, shells, and upstream bzip2.

What is new in version 0.12:

• The shell script test.sh tests the installed instance of lbzip2, which can be different from the currently built one. pbzip2 is not a requirement for testing anymore, but test.sh will try to measure its performance if it's available.
• The same applies to the bzip2 module of 7za (from p7zip).
• Some GNU/Linux specific hints on enabling SUSv2 conformance (which is required for building and testing) were added to the README.

What is new in version 0.11:

• This release adds support for testing by end-users in a portable way.