From e1273106f62927e3efdb1cfa107cb1a9f913274c Mon Sep 17 00:00:00 2001 From: Vicent Marti Date: Thu, 14 Nov 2013 07:43:51 -0500 Subject: 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 Signed-off-by: Jeff King Helped-by: Ramsay Jones Signed-off-by: Junio C Hamano --- Makefile | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 48ff0bdb18..64a1ed7877 100644 --- a/Makefile +++ b/Makefile @@ -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) -- cgit v1.2.3