diff options
Diffstat (limited to 'hashmap.h')
-rw-r--r-- | hashmap.h | 31 |
1 files changed, 29 insertions, 2 deletions
@@ -236,13 +236,40 @@ void hashmap_init(struct hashmap *map, void hashmap_free_(struct hashmap *map, ssize_t offset); /* - * Frees a hashmap structure and allocated memory, leaves entries undisturbed + * Frees a hashmap structure and allocated memory for the table, but does not + * free the entries nor anything they point to. + * + * Usage note: + * + * Many callers will need to iterate over all entries and free the data each + * entry points to; in such a case, they can free the entry itself while at it. + * Thus, you might see: + * + * hashmap_for_each_entry(map, hashmap_iter, e, hashmap_entry_name) { + * free(e->somefield); + * free(e); + * } + * hashmap_free(map); + * + * instead of + * + * hashmap_for_each_entry(map, hashmap_iter, e, hashmap_entry_name) { + * free(e->somefield); + * } + * hashmap_free_entries(map, struct my_entry_struct, hashmap_entry_name); + * + * to avoid the implicit extra loop over the entries. However, if there are + * no special fields in your entry that need to be freed beyond the entry + * itself, it is probably simpler to avoid the explicit loop and just call + * hashmap_free_entries(). */ #define hashmap_free(map) hashmap_free_(map, -1) /* * Frees @map and all entries. @type is the struct type of the entry - * where @member is the hashmap_entry struct used to associate with @map + * where @member is the hashmap_entry struct used to associate with @map. + * + * See usage note above hashmap_free(). */ #define hashmap_free_entries(map, type, member) \ hashmap_free_(map, offsetof(type, member)); |