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Diffstat (limited to 'src/libbasic/include/basic/hash-funcs.h')
-rw-r--r-- | src/libbasic/include/basic/hash-funcs.h | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/libbasic/include/basic/hash-funcs.h b/src/libbasic/include/basic/hash-funcs.h new file mode 100644 index 0000000000..299189d143 --- /dev/null +++ b/src/libbasic/include/basic/hash-funcs.h @@ -0,0 +1,65 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + Copyright 2014 Michal Schmidt + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "macro.h" +#include "siphash24.h" + +typedef void (*hash_func_t)(const void *p, struct siphash *state); +typedef int (*compare_func_t)(const void *a, const void *b); + +struct hash_ops { + hash_func_t hash; + compare_func_t compare; +}; + +void string_hash_func(const void *p, struct siphash *state); +int string_compare_func(const void *a, const void *b) _pure_; +extern const struct hash_ops string_hash_ops; + +/* This will compare the passed pointers directly, and will not + * dereference them. This is hence not useful for strings or + * suchlike. */ +void trivial_hash_func(const void *p, struct siphash *state); +int trivial_compare_func(const void *a, const void *b) _const_; +extern const struct hash_ops trivial_hash_ops; + +/* 32bit values we can always just embed in the pointer itself, but + * in order to support 32bit archs we need store 64bit values + * indirectly, since they don't fit in a pointer. */ +void uint64_hash_func(const void *p, struct siphash *state); +int uint64_compare_func(const void *a, const void *b) _pure_; +extern const struct hash_ops uint64_hash_ops; + +/* On some archs dev_t is 32bit, and on others 64bit. And sometimes + * it's 64bit on 32bit archs, and sometimes 32bit on 64bit archs. Yuck! */ +#if SIZEOF_DEV_T != 8 +void devt_hash_func(const void *p, struct siphash *state) _pure_; +int devt_compare_func(const void *a, const void *b) _pure_; +extern const struct hash_ops devt_hash_ops = { + .hash = devt_hash_func, + .compare = devt_compare_func +}; +#else +#define devt_hash_func uint64_hash_func +#define devt_compare_func uint64_compare_func +#define devt_hash_ops uint64_hash_ops +#endif |