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| author | Vicent Marti <tanoku@gmail.com> | 2013-11-14 07:43:51 -0500 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2013-12-30 12:17:20 -0800 |
| commit | e1273106f62927e3efdb1cfa107cb1a9f913274c (patch) | |
| tree | 9a23af0dbec1791e1a0d8b3137e614744ee14f19 /Makefile | |
| parent | 7e3dae494370b5596a6ea76af1191829ce11bce2 (diff) | |
| download | git-e1273106f62927e3efdb1cfa107cb1a9f913274c.tar.gz git-e1273106f62927e3efdb1cfa107cb1a9f913274c.tar.xz | |
ewah: compressed bitmap implementation
EWAH is a word-aligned compressed variant of a bitset (i.e. a data
structure that acts as a 0-indexed boolean array for many entries).
It uses a 64-bit run-length encoding (RLE) compression scheme,
trading some compression for better processing speed.
The goal of this word-aligned implementation is not to achieve
the best compression, but rather to improve query processing time.
As it stands right now, this EWAH implementation will always be more
efficient storage-wise than its uncompressed alternative.
EWAH arrays will be used as the on-disk format to store reachability
bitmaps for all objects in a repository while keeping reasonable sizes,
in the same way that JGit does.
This EWAH implementation is a mostly straightforward port of the
original `javaewah` library that JGit currently uses. The library is
self-contained and has been embedded whole (4 files) inside the `ewah`
folder to ease redistribution.
The library is re-licensed under the GPLv2 with the permission of Daniel
Lemire, the original author. The source code for the C version can
be found on GitHub:
https://github.com/vmg/libewok
The original Java implementation can also be found on GitHub:
https://github.com/lemire/javaewah
[jc: stripped debug-only code per Peff's $gmane/239768]
Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 11 |
1 files changed, 9 insertions, 2 deletions
@@ -667,6 +667,8 @@ LIB_H += diff.h LIB_H += diffcore.h LIB_H += dir.h LIB_H += exec_cmd.h +LIB_H += ewah/ewok.h +LIB_H += ewah/ewok_rlw.h LIB_H += fetch-pack.h LIB_H += fmt-merge-msg.h LIB_H += fsck.h @@ -800,6 +802,10 @@ LIB_OBJS += dir.o LIB_OBJS += editor.o LIB_OBJS += entry.o LIB_OBJS += environment.o +LIB_OBJS += ewah/bitmap.o +LIB_OBJS += ewah/ewah_bitmap.o +LIB_OBJS += ewah/ewah_io.o +LIB_OBJS += ewah/ewah_rlw.o LIB_OBJS += exec_cmd.o LIB_OBJS += fetch-pack.o LIB_OBJS += fsck.o @@ -2474,8 +2480,9 @@ profile-clean: $(RM) $(addsuffix *.gcno,$(addprefix $(PROFILE_DIR)/, $(object_dirs))) clean: profile-clean coverage-clean - $(RM) *.o *.res block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o xdiff/*.o vcs-svn/*.o \ - builtin/*.o $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB) + $(RM) *.o *.res block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o + $(RM) xdiff/*.o vcs-svn/*.o ewah/*.o builtin/*.o + $(RM) $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB) $(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X $(RM) $(TEST_PROGRAMS) $(NO_INSTALL) $(RM) -r bin-wrappers $(dep_dirs) |