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Huge rewrite of buffer reading in rzip.c. We use a wrapper instead of

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accessing the buffer directly, thus allowing us to have window sizes larger than
available ram. This is implemented through the use of a "sliding mmap"
implementation. Sliding mmap uses two mmapped buffers, one large one as
previously, and one page sized smaller one. When an attempt is made to read
beyond the end of the large buffer, the small buffer is remapped to the file
area that's being accessed. While this implementation is 100x slower than direct
mmapping, it allows us to implement unlimited sized compression windows.
Implement the -U option with unlimited sized windows.
Rework the selection of compression windows. Instead of trying to guess how
much ram the machine might be able to access, we try to safely buffer as much
ram as we can, and then use that to determine the file buffer size. Do not
choose an arbitrary upper window limit unless -w is specified.
Rework the -M option to try to buffer the entire file, reducing the buffer
size until we succeed.
Align buffer sizes to page size.
Clean up lots of unneeded variables.
Fix lots of minor logic issues to do with window sizes accepted/passed to rzip
and the compression backends.
More error handling.
Change -L to affect rzip compression level directly as well as backend
compression level and use 9 by default now.
More cleanups of information output.
Use 3 point release numbering in case one minor version has many subversions.
Numerous minor cleanups and tidying.
Updated docs and manpages.
This commit is contained in:
Con Kolivas 2010-11-04 21:14:55 +11:00
parent c106128d1a
commit 29b166629a
12 changed files with 400 additions and 256 deletions
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34
ChangeLog
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@ -1,4 +1,38 @@
lrzip ChangeLog
NOVEMBER 2010, version 0.5.1 Con Kolivas
* Fix Darwin build - Darwin doesn't support mremap so introduce a fake wrapper
for it.
* Fix the memopen routines, a wrongly implemented wrapper for Darwin equivalents
was also using the faked versions on all builds.
* Fix dodgy ordered includes.
* Clean up excessive use of #ifdefs
* Huge rewrite of buffer reading in rzip.c. We use a wrapper instead of
accessing the buffer directly, thus allowing us to have window sizes larger than
available ram. This is implemented through the use of a "sliding mmap"
implementation. Sliding mmap uses two mmapped buffers, one large one as
previously, and one page sized smaller one. When an attempt is made to read
beyond the end of the large buffer, the small buffer is remapped to the file
area that's being accessed. While this implementation is 100x slower than direct
mmapping, it allows us to implement unlimited sized compression windows.
* Implement the -U option with unlimited sized windows.
* Rework the selection of compression windows. Instead of trying to guess how
much ram the machine might be able to access, we try to safely buffer as much
ram as we can, and then use that to determine the file buffer size. Do not
choose an arbitrary upper window limit unless -w is specified.
* Rework the -M option to try to buffer the entire file, reducing the buffer
size until we succeed.
* Align buffer sizes to page size.
* Clean up lots of unneeded variables.
* Fix lots of minor logic issues to do with window sizes accepted/passed to rzip
and the compression backends.
* More error handling.
* Change -L to affect rzip compression level directly as well as backend
compression level and use 9 by default now.
* More cleanups of information output.
* Use 3 point release numbering in case one minor version has many subversions.
* Numerous minor cleanups and tidying.
* Updated docs and manpages.
NOVEMBER 2010, version 0.5 Con Kolivas
* Changed offset encoding in rzip stage to use variable byte width offsets
instead of 64 bits wide. Makes for better compression and slightly faster.