Commit Graph

5 Commits

Author SHA1 Message Date
Ramsay Jones
3a457a08f2 ewok_rlw.h: add missing 'inline' to function definition
The 'ewok_rlw.h' header file contains the rlw_get_run_bit() function
definition, which is marked as 'static' but not 'inline'. At least when
compiled by gcc, with the default -O2 optimization level, the function
is actually inlined and leaves no static version in the ewah_bitmap.o
and ewah_rlw.o object files. Despite this, add the missing 'inline'
keyword to better describe the intended behaviour.

Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-29 10:14:19 +09:00
Ramsay Jones
9623514aa8 ewah/ewok_rlw.h: add missing include (hdr-check)
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-20 11:50:00 -07:00
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>
2018-06-21 09:39:48 -07:00
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>
2017-11-09 13:21:21 +09:00
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>
2013-12-30 12:17:20 -08:00