Parallel BZIP2

Parallel BZIP2 project is a parallel implementation of the bzip2 block- sorting file compressor that uses pthreads and achieves near-linear speedup on SMP machines. The output of this version is fully compatible with bzip2 1.0.2 (ie: anything compressed with PBZIP2 can be decompressed with bzip2).

PBZIP2 should work on any system that has a pthreads compatible C++ compiler (such as gcc). It has been tested on: Linux, Windows (cygwin & MinGW), Solaris, Tru64/OSF1, HP-UX, and Irix.

What is new in this release:

• Fixed bug - deadlock due to unsynchronized broadcasts (bug #876686)
• Prevent deletion of input files on error (bug #874543)
• Document how to compress/decompress from standard input (bug #820525)
• Added more detailed kernel error messages (bug #874605)
• Fixes for error handling in muliti-file processing (bug #883782)

What is new in version 1.1.5:

• This version fixes excessive output permissions while compress/decompress is in progress.
• It now emulates the same behaviour as bzip2.

What is new in version 1.1.4:

• Fixed hang on decompress with --ignore-trailing-garbage=1 when producer is interrupted on trailing garbage (bug #762464)
• Added example to help for decompression piped to tar (bug #746806)
• Fixed typo in Trailing Garbage printed message (bug #746799)

What is new in version 1.1.3:

• Fixed hang on decompress with --ignore-trailing-garbage=1 and higher numCPU (e.g. > 2) (bug #740502)
• Print trailing garbage errors even when in quiet mode (bug #743635)
• Default extension on decompress of .tbz2 changed to .tar for bzip2 compatibility (bug #743639)

What is new in version 1.1.2:

• Fix directdecompress segfault when destination file can't be opened (e.g. read-only) (bug #717852)
• Implemented --ignore-trailing-garbage feature (bug #594868)
• Fixed hang on decompress of some truncated archives (bug #590225)
• Pulled an error check out of normal logic block for clarity
• Debug print added after BZ2_bzDecompress to track it's return code.
• A debug print fixed in queue::remove
• Increased max memory usage limit from 1GB to 2GB
• If no -m switch given on command line, default max memory limit will now automatically increase from 100 MB to minimum amount of memory required to support the number of CPUs requested
• Improved performance when output buffer is full
• Fixed bug which caused hang while decompressing prematurely truncated bzip2 stream
• Consumer_decompress throttling modified to prevent potential deadlock/infinite loop in certain situations (Thanks to Laszlo Ersek for finding and helping track down the cause of this bug)
• Fixed deadlock bug and performance issue when consumer working with long bzip2 sequences (Thanks to Tanguy Fautre for finding)
• Fixed error message for block size range (max size was wrong)
• Moved #include from pbzip2.cpp to pbzip2.h to fix OS/2 compiler issue

What is new in version 1.1.0:

• Added support for multi-threaded decompression using STDIN/pipes
• Added code to support throttling compression to prevent memory exhaustion with slow output pipe
• Added -m switch to specify amount of max memory usage before throttling starts (default 100MB)
• Fixed bug that did not allow command line parameters to be used when compressing data from stdin
• Added long options to man page and -h output
• Added --loadavg, --read long options
• Added support for CPU detection on Win32
• Major improvements to protection of shared variables, error and signal handling, program termination
• Added -S switch for thread stack size customization on Solaris (needs USE_STACKSIZE_CUSTOMIZATION defined when compiling)
• Fixed command line parsing bug for -b, -p, -m switches
• Fixed infinite loop on when fileWriter fails to create output file at start
• Fixed bug that deleted input filename (with .bz2 extension for compression and without .bz2 extension for decompression) when a user interrupts process with CTRL-C while outputting to STDOUT
• Fixed bug where 0 byte files were not processed properly when data input from STDIN
• Ignores fwrite return and passes chown errors in writeFileMetaData if effective uid root
• OutputBuffer usage redesigned as fixed-size circular buffer
• Lots of minor bugs fixed (see AUTHORS or pbzip2.cpp for full details)
• Special thanks to Javor Nikolov for providing the majority of contributions to this release and a significant amount of testing

What is new in version 1.0.5:

• This release properly complains about trying to read or write compressed data to the terminal, and exits.
• It further fixes the CPU detection crash, and the Makefile has been updated to force deletion when cleaning.

What is new in version 1.0.4:

• Support was added for using pbzip2 with tar and for all remaining bzip2 command line options, so pbzip2 can be used as a drop-in replacement for bzip2.
• A bug was fixed that would cause pbzip2 to crash if detection of the number of processors failed.
• Compiling with uclibc is now supported.

What is new in version 1.0.3:

• The ability to compress, decompress, and test data using stdin and pipes is now supported.
• Support was also added to directly decompress files without using threads when files are small, the system only has 1 CPU, or if the .bz2 file contains 1 bzip2 stream.
• This version can now compress 0 byte files like bzip2.
• Support for pbzcat symlink to automatically specify a decompression mode to stdout, just like bzcat, is now included.

Requirements:

• bzip2