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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 09:25:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 09:25:10 +0000 |
commit | 5dced3d1b3deca80e01415a2e35dc7972dcbfae7 (patch) | |
tree | 6a403684e0978f0287d7f0ec0e5aab1fd31a59e1 /lib/ext2fs/hashmap.c | |
parent | Initial commit. (diff) | |
download | e2fsprogs-5dced3d1b3deca80e01415a2e35dc7972dcbfae7.tar.xz e2fsprogs-5dced3d1b3deca80e01415a2e35dc7972dcbfae7.zip |
Adding upstream version 1.47.0.upstream/1.47.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/ext2fs/hashmap.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/lib/ext2fs/hashmap.c b/lib/ext2fs/hashmap.c new file mode 100644 index 0000000..697b2bc --- /dev/null +++ b/lib/ext2fs/hashmap.c @@ -0,0 +1,109 @@ +#include "hashmap.h" +#include <string.h> + +struct ext2fs_hashmap { + uint32_t size; + uint32_t(*hash)(const void *key, size_t len); + void(*free)(void*); + struct ext2fs_hashmap_entry *first; + struct ext2fs_hashmap_entry *last; +#if __GNUC_PREREQ (4, 8) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wpedantic" +#endif + struct ext2fs_hashmap_entry *entries[0]; +#if __GNUC_PREREQ (4, 8) +#pragma GCC diagnostic pop +#endif +}; + +uint32_t ext2fs_djb2_hash(const void *str, size_t size) +{ + int c; + const char *s = str; + uint32_t hash = 5381; + + while (size-- > 0) { + c = *s++; + hash = ((hash << 5) + hash) + c; + } + return hash; +} + +struct ext2fs_hashmap *ext2fs_hashmap_create( + uint32_t(*hash_fct)(const void*, size_t), + void(*free_fct)(void*), size_t size) +{ + struct ext2fs_hashmap *h = calloc(sizeof(struct ext2fs_hashmap) + + sizeof(struct ext2fs_hashmap_entry) * size, 1); + if (!h) + return NULL; + + h->size = size; + h->free = free_fct; + h->hash = hash_fct; + h->first = h->last = NULL; + return h; +} + +int ext2fs_hashmap_add(struct ext2fs_hashmap *h, + void *data, const void *key, size_t key_len) +{ + uint32_t hash = h->hash(key, key_len) % h->size; + struct ext2fs_hashmap_entry *e = malloc(sizeof(*e)); + + if (!e) + return -1; + + e->data = data; + e->key = key; + e->key_len = key_len; + e->next = h->entries[hash]; + h->entries[hash] = e; + + e->list_prev = NULL; + e->list_next = h->first; + if (h->first) + h->first->list_prev = e; + h->first = e; + if (!h->last) + h->last = e; + + return 0; +} + +void *ext2fs_hashmap_lookup(struct ext2fs_hashmap *h, const void *key, + size_t key_len) +{ + struct ext2fs_hashmap_entry *iter; + uint32_t hash = h->hash(key, key_len) % h->size; + + for (iter = h->entries[hash]; iter; iter = iter->next) + if (iter->key_len == key_len && !memcmp(iter->key, key, key_len)) + return iter->data; + return NULL; +} + +void *ext2fs_hashmap_iter_in_order(struct ext2fs_hashmap *h, + struct ext2fs_hashmap_entry **it) +{ + *it = *it ? (*it)->list_next : h->first; + return *it ? (*it)->data : NULL; +} + +void ext2fs_hashmap_free(struct ext2fs_hashmap *h) +{ + size_t i; + + for (i = 0; i < h->size; ++i) { + struct ext2fs_hashmap_entry *it = h->entries[i]; + while (it) { + struct ext2fs_hashmap_entry *tmp = it->next; + if (h->free) + h->free(it->data); + free(it); + it = tmp; + } + } + free(h); +} |