kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Derrick Stolee	ed03a58b65	bitmap: implement bitmap_is_subset() The bitmap_is_subset() function checks if the 'self' bitmap contains any bitmaps that are not on in the 'other' bitmap. Up until this patch, it had a declaration, but no implementation or callers. A subsequent patch will want this function, so implement it here. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jeff King	ccae08e822	ewah: add bitmap_dup() function There's no easy way to make a copy of a bitmap. Obviously a caller can iterate over the bits and set them one by one in a new bitmap, but we can go much faster by copying whole words with memcpy(). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Jeff King	cc4aa28506	bitmap: add bitmap_unset() function We've never needed to unset an individual bit in a bitmap until now. Typically they start with all bits unset and we bitmap_set() them, or we are applying another bitmap as a mask. But the easiest way to apply an object filter to a bitmap result will be to unset the individual bits. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Jeff King	14fbd26044	ewah/bitmap: introduce bitmap_word_alloc() In a following commit we will need to allocate a variable number of bitmap words, instead of always 32, so let's add bitmap_word_alloc() for this purpose. Note that we have to adjust the block growth in bitmap_set(), since a caller could now use an initial size of "0" (we don't plan to do that, but it doesn't hurt to be defensive). Helped-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Junio C Hamano	c806278e0c	ewah: delete unused 'rlwit_discharge_empty()' 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>	7 years ago
Jeff King	26675087a5	ewah: drop ewah_serialize_native function We don't call this function, and never have. The on-disk bitmap format uses network-byte-order integers, meaning that we cannot use the native-byte-order format written here. Let's drop it in the name of simplicity. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Jeff King	caa88140d4	ewah: drop ewah_deserialize function We don't call this function, and in fact never have since it was added (at least not in iterations of the ewah patches that got merged). Instead we use ewah_read_mmap(). Let's drop the unused code. Note to anybody who later wants to resurrect this: it does not check for integer overflow in the ewah data size, meaning it may be possible to convince the code to allocate a too-small buffer and read() into it. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Derrick Stolee	83ea4e1e59	ewah_io: delete unused 'ewah_serialize()' 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>	7 years ago
Derrick Stolee	a9fda811fc	ewah_bitmap: delete unused 'ewah_or()' 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>	7 years ago
Derrick Stolee	44301d2b76	ewah_bitmap: delete unused 'ewah_not()' 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>	7 years ago
Derrick Stolee	19436fe03a	ewah_bitmap: delete unused 'ewah_and_not()' 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>	7 years ago
Derrick Stolee	01b4a63f55	ewah_bitmap: delete unused 'ewah_and()' 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>	7 years ago
Derrick Stolee	48dc98344f	ewah/bitmap.c: delete unused 'bitmap_each_bit()' 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>	7 years ago
Derrick Stolee	b36c3134bb	ewah/bitmap.c: delete unused 'bitmap_clear()' 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>	7 years ago
Jeff King	9d2e330b17	ewah_read_mmap: bounds-check mmap reads The on-disk ewah format tells us how big the ewah data is, and we blindly read that much from the buffer without considering whether the mmap'd data is long enough, which can lead to out-of-bound reads. Let's make sure we have data available before reading it, both for the ewah header/footer as well as for the bit data itself. In particular: - keep our ptr/len pair in sync as we move through the buffer, and check it before each read - check the size for integer overflow (this should be impossible on 64-bit, as the size is given as a 32-bit count of 8-byte words, but is possible on a 32-bit system) - return the number of bytes read as an ssize_t instead of an int, again to prevent integer overflow - compute the return value using a pointer difference; this should yield the same result as the existing code, but makes it more obvious that we got our computations right The included test is far from comprehensive, as it just picks a static point at which to truncate the generated bitmap. But in practice this will hit in the middle of an ewah and make sure we're at least exercising this code. Reported-by: Luat Nguyen <root@l4w.io> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Todd Zullinger	484257925f	Replace Free Software Foundation address in license notices 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>	7 years ago
Jeff King	fb7dbf3e7a	convert ewah/bitmap code to use xmalloc 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>	9 years ago
Jeff King	34b935c01f	ewah: use less generic macro name 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>	10 years ago
Nguyễn Thái Ngọc Duy	be0d9d5323	ewah: add convenient wrapper ewah_serialize_strbuf() Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	10 years ago
Tom G. Christensen	bd4e8822da	ewah: fix building with gcc < 3.4.0 The __builtin_ctzll function was added in gcc 3.4.0. This extends the check for gcc so that use of __builtin_ctzll is only enabled if gcc >= 3.4.0. Signed-off-by: Tom G. Christensen <tgc@statsbiblioteket.dk> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	10 years ago
Nguyễn Thái Ngọc Duy	16fc2b7a9c	ewah: delete unused ewah_read_mmap_native declaration Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	11 years ago
Nguyễn Thái Ngọc Duy	a0a2f7d79c	ewah: fix constness of ewah_read_mmap Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	11 years ago
Vicent Marti	e1273106f6	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>	11 years ago

26 Commits (e9e8adf1a871d22d9df7498256681685459b2507)