Instead of switching directly from the lazy compressor at level 7 to the
near-optimal compressor at level 8, use the lazy2 compressor at levels
8-9 and don't switch to near-optimal until level 10.
This avoids poor compression ratio and bad performance (both
significantly worse than level 7, and significantly worse than zlib) at
levels 8-9 on data where the near-optimal compressor doesn't do well
until the parameters are cranked up.
On data where the near-optimal compressor *does* do well, this change
worsens the compression ratio of levels 8-9, but also speeds them up a
lot, thus positioning them similarly vs. zlib as the lower levels (i.e.
much faster and slightly stronger, rather than slightly faster and much
stronger). The difference between levels 9 and 10 is increased, but
that's perhaps the least bad place to have a discontinuity.
Resolves https://github.com/ebiggers/libdeflate/issues/85
Use a lower max_search_depth but a higher nice_match_length. This seems
to turn out a bit better, on average. This is consistent with what the
other compression levels do; level 4 was the only one that had
nice_match_length <= max_search_depth.
The new match scoring method in the lazy compressor has improved the
compression ratio slightly. Therefore, for levels 5-6 decrease
max_search_depth slightly to get a bit more performance.
We pull the version out of libdeflate.h into the
Makefile, and then sed a few macros out of the new
file libdeflate.pc.in. Set the necessary Cflags
and Libs (CFLAGS and LFLAGS) based off compile-time
definitions. Depend on the Makefile to pick up
version changes. Update uninstall target.
Signed-off-by: nick black <dankamongmen@gmail.com>
Environment variable DISABLE_SHARED (following convention of --disable-shared
of ./configure script) disables building of shared library and shared lib
symlink. It makes life of downstream maintainer easier when maintaining package
for environment that supports only static libraries.
See https://github.com/NixOS/nixpkgs/pull/144438
The '-t' option of GNU gzip allows checking whether a gzip file is valid
without writing the data anywhere. It's relatively straightforward to
support in libdeflate-gzip too, so add support for it.
Resolves https://github.com/ebiggers/libdeflate/issues/125
[EB - updated commit message]
A lot of the internal library headers don't have include guards because
they aren't needed. It might look like a bug, though, and it doesn't
hurt to add them. So do this.
Update https://github.com/ebiggers/libdeflate/issues/117
I saw this tweet claiming this flag makes libdeflate run 20% faster on
WebAssembly: https://twitter.com/Algunenano/status/1317098341377900550.
Indeed, when tried even in a complex PNG compression benchmark I've
observed 10-15% improvement when this flag is enabled.
Even though WebAssembly might be running on top of a variety of
underlying platforms, the spec requires it to support unaligned access,
and on majority of platforms it will translate to a faster code.
Hence, I think it makes sense to enable this flag by default.
Include sys/types.h to avoid the following build failure on uclibc:
In file included from programs/gzip.c:28:0:
programs/prog_util.h:159:1: error: unknown type name ‘ssize_t’
ssize_t xread(struct file_stream *strm, void *buf, size_t count);
^
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
