summaryrefslogtreecommitdiff
path: root/ewah/ewah_bitmap.c
AgeCommit message (Collapse)AuthorFilesLines
2020-12-08ewah/ewah_bitmap.c: avoid open-coding ALLOC_GROW()Libravatar Taylor Blau1-11/+4
'ewah/ewah_bitmap.c:buffer_grow()' is responsible for growing the buffer used to store the bits of an EWAH bitmap. It is essentially doing the same task as the 'ALLOC_GROW()' macro, so use that instead. This simplifies the callers of 'buffer_grow()', who no longer have to ask for a specific size, but rather specify how much of the buffer they need. They also no longer need to guard 'buffer_grow()' behind an if statement, since 'ALLOC_GROW()' (and, by extension, 'buffer_grow()') is a noop if the buffer is already large enough. But, the most significant change is that this fixes a bug when calling buffer_grow() with both 'alloc_size' and 'new_size' set to 1. In this case, truncating integer math will leave the new size set to 1, causing the buffer to never grow. Instead, let alloc_nr() handle this, which asks for '(new_size + 16) * 3 / 2' instead of 'new_size * 3 / 2'. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-21ewah: delete unused 'rlwit_discharge_empty()'Libravatar Junio C Hamano1-8/+12
Complete the removal of unused 'ewah bitmap' code by removing the now unused 'rlwit_discharge_empty()' function. Also, the 'ewah_clear()' function can now be made a file-scope static symbol. Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-18ewah_bitmap: delete unused 'ewah_or()'Libravatar Derrick Stolee1-69/+0
Reported-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-18ewah_bitmap: delete unused 'ewah_not()'Libravatar Derrick Stolee1-19/+0
Reported-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-18ewah_bitmap: delete unused 'ewah_and_not()'Libravatar Derrick Stolee1-73/+0
Reported-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-18ewah_bitmap: delete unused 'ewah_and()'Libravatar Derrick Stolee1-68/+0
Reported-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-09Replace Free Software Foundation address in license noticesLibravatar Todd Zullinger1-2/+1
The mailing address for the FSF has changed over the years. Rather than updating the address across all files, refer readers to gnu.org, as the GNU GPL documentation now suggests for license notices. The mailing address is retained in the full license files (COPYING and LGPL-2.1). The old address is still present in t/diff-lib/COPYING. This is intentional, as the file is used in tests and the contents are not expected to change. Signed-off-by: Todd Zullinger <tmz@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-10use DIV_ROUND_UPLibravatar René Scharfe1-2/+2
Convert code that divides and rounds up to use DIV_ROUND_UP to make the intent clearer and reduce the number of magic constants. Signed-off-by: Rene Scharfe <l.s.r@web.de> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22ewah: convert to REALLOC_ARRAY, etcLibravatar Jeff King1-3/+2
Now that we're built around xmalloc and friends, we can use helpers like REALLOC_ARRAY, ALLOC_GROW, and so on to make the code shorter and protect against integer overflow. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22convert ewah/bitmap code to use xmallocLibravatar Jeff King1-6/+3
This code was originally written with the idea that it could be spun off into its own ewah library, and uses the overrideable ewah_malloc to do allocations. We plug in xmalloc as our ewah_malloc, of course. But over the years the ewah code itself has become more entangled with git, and the return value of many ewah_malloc sites is not checked. Let's just drop the level of indirection and use xmalloc and friends directly. This saves a few lines, and will let us adapt these sites to our more advanced malloc helpers. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-03ewah: use less generic macro nameLibravatar Jeff King1-11/+11
The ewah/ewok.h header pollutes the global namespace with "BITS_IN_WORD", without any specific notion that we are talking about the bits in an eword_t. We can give this the more specific name "BITS_IN_EWORD". Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-22ewah_bitmap.c: do not assume size_t and eword_t are the same sizeLibravatar Kyle J. McKay1-1/+1
When buffer_grow changes the size of the buffer using realloc, it first computes and saves the rlw pointer's offset into the buffer using (uint8_t *) math before the realloc but then restores it using (eword_t *) math. In order to do this it's necessary to convert the (uint8_t *) offset into an (eword_t *) offset. It was doing this by dividing by the sizeof(size_t). Unfortunately sizeof(size_t) is not same as sizeof(eword_t) on all platforms. This causes illegal memory accesses and other bad things to happen when attempting to use bitmaps on those platforms. Fix this by dividing by the sizeof(eword_t) instead which will always be correct for all platforms. Signed-off-by: Kyle J. McKay <mackyle@gmail.com> Acked-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-30ewah: compressed bitmap implementationLibravatar Vicent Marti1-0/+714
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>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 18:32:04 +0000