/* SPDX-License-Identifier: LGPL-2.1+ */ #include #include "hash-funcs.h" #include "path-util.h" void string_hash_func(const char *p, struct siphash *state) { siphash24_compress(p, strlen(p) + 1, state); } DEFINE_HASH_OPS(string_hash_ops, char, string_hash_func, string_compare_func); DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(string_hash_ops_free, char, string_hash_func, string_compare_func, free); DEFINE_HASH_OPS_FULL(string_hash_ops_free_free, char, string_hash_func, string_compare_func, free, char, free); void path_hash_func(const char *q, struct siphash *state) { size_t n; assert(q); assert(state); /* Calculates a hash for a path in a way this duplicate inner slashes don't make a differences, and also * whether there's a trailing slash or not. This fits well with the semantics of path_compare(), which does * similar checks and also doesn't care for trailing slashes. Note that relative and absolute paths (i.e. those * which begin in a slash or not) will hash differently though. */ n = strspn(q, "/"); if (n > 0) { /* Eat up initial slashes, and add one "/" to the hash for all of them */ siphash24_compress(q, 1, state); q += n; } for (;;) { /* Determine length of next component */ n = strcspn(q, "/"); if (n == 0) /* Reached the end? */ break; /* Add this component to the hash and skip over it */ siphash24_compress(q, n, state); q += n; /* How many slashes follow this component? */ n = strspn(q, "/"); if (q[n] == 0) /* Is this a trailing slash? If so, we are at the end, and don't care about the slashes anymore */ break; /* We are not add the end yet. Hash exactly one slash for all of the ones we just encountered. */ siphash24_compress(q, 1, state); q += n; } } DEFINE_HASH_OPS(path_hash_ops, char, path_hash_func, path_compare); DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(path_hash_ops_free, char, path_hash_func, path_compare, free); void trivial_hash_func(const void *p, struct siphash *state) { siphash24_compress(&p, sizeof(p), state); } int trivial_compare_func(const void *a, const void *b) { return CMP(a, b); } const struct hash_ops trivial_hash_ops = { .hash = trivial_hash_func, .compare = trivial_compare_func, }; void uint64_hash_func(const uint64_t *p, struct siphash *state) { siphash24_compress(p, sizeof(uint64_t), state); } int uint64_compare_func(const uint64_t *a, const uint64_t *b) { return CMP(*a, *b); } DEFINE_HASH_OPS(uint64_hash_ops, uint64_t, uint64_hash_func, uint64_compare_func); #if SIZEOF_DEV_T != 8 void devt_hash_func(const dev_t *p, struct siphash *state) { siphash24_compress(p, sizeof(dev_t), state); } int devt_compare_func(const dev_t *a, const dev_t *b) { return CMP(*a, *b); } DEFINE_HASH_OPS(devt_hash_ops, dev_t, devt_hash_func, devt_compare_func); #endif