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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:16:24 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:16:24 +0000 |
commit | 9221dca64f0c8b5de72727491e41cf63e902eaab (patch) | |
tree | d8cbbf520eb4b5c656a54b2e36947008dcb751ad /gl/lib/hash-pjw.c | |
parent | Initial commit. (diff) | |
download | man-db-9221dca64f0c8b5de72727491e41cf63e902eaab.tar.xz man-db-9221dca64f0c8b5de72727491e41cf63e902eaab.zip |
Adding upstream version 2.8.5.upstream/2.8.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gl/lib/hash-pjw.c')
-rw-r--r-- | gl/lib/hash-pjw.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/gl/lib/hash-pjw.c b/gl/lib/hash-pjw.c new file mode 100644 index 0000000..74f8b1c --- /dev/null +++ b/gl/lib/hash-pjw.c @@ -0,0 +1,40 @@ +/* hash-pjw.c -- compute a hash value from a NUL-terminated string. + + Copyright (C) 2001, 2003, 2006, 2009-2019 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +#include "hash-pjw.h" + +#include <limits.h> + +#define SIZE_BITS (sizeof (size_t) * CHAR_BIT) + +/* A hash function for NUL-terminated char* strings using + the method described by Bruno Haible. + See https://www.haible.de/bruno/hashfunc.html. */ + +size_t +hash_pjw (const void *x, size_t tablesize) +{ + const char *s; + size_t h = 0; + + for (s = x; *s; s++) + h = *s + ((h << 9) | (h >> (SIZE_BITS - 9))); + + return h % tablesize; +} |