From ae20bf1ad98bdc716879a8da99e7f329e3cc2730 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Mon, 2 Nov 2020 18:55:06 +0000 Subject: strmap: new utility functions Add strmap as a new struct and associated utility functions, specifically for hashmaps that map strings to some value. The API is taken directly from Peff's proposal at https://lore.kernel.org/git/20180906191203.GA26184@sigill.intra.peff.net/ Note that similar string-list, I have a strdup_strings setting. However, unlike string-list, strmap_init() does not take a parameter for this setting and instead automatically sets it to 1; callers who want to control this detail need to instead call strmap_init_with_options(). (Future patches will add additional parameters to strmap_init_with_options()). Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- strmap.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) create mode 100644 strmap.c (limited to 'strmap.c') diff --git a/strmap.c b/strmap.c new file mode 100644 index 0000000000..53f284eb20 --- /dev/null +++ b/strmap.c @@ -0,0 +1,99 @@ +#include "git-compat-util.h" +#include "strmap.h" + +int cmp_strmap_entry(const void *hashmap_cmp_fn_data, + const struct hashmap_entry *entry1, + const struct hashmap_entry *entry2, + const void *keydata) +{ + const struct strmap_entry *e1, *e2; + + e1 = container_of(entry1, const struct strmap_entry, ent); + e2 = container_of(entry2, const struct strmap_entry, ent); + return strcmp(e1->key, e2->key); +} + +static struct strmap_entry *find_strmap_entry(struct strmap *map, + const char *str) +{ + struct strmap_entry entry; + hashmap_entry_init(&entry.ent, strhash(str)); + entry.key = str; + return hashmap_get_entry(&map->map, &entry, ent, NULL); +} + +void strmap_init(struct strmap *map) +{ + strmap_init_with_options(map, 1); +} + +void strmap_init_with_options(struct strmap *map, + int strdup_strings) +{ + hashmap_init(&map->map, cmp_strmap_entry, NULL, 0); + map->strdup_strings = strdup_strings; +} + +static void strmap_free_entries_(struct strmap *map, int free_values) +{ + struct hashmap_iter iter; + struct strmap_entry *e; + + if (!map) + return; + + /* + * We need to iterate over the hashmap entries and free + * e->key and e->value ourselves; hashmap has no API to + * take care of that for us. Since we're already iterating over + * the hashmap, though, might as well free e too and avoid the need + * to make some call into the hashmap API to do that. + */ + hashmap_for_each_entry(&map->map, &iter, e, ent) { + if (free_values) + free(e->value); + if (map->strdup_strings) + free((char*)e->key); + free(e); + } +} + +void strmap_clear(struct strmap *map, int free_values) +{ + strmap_free_entries_(map, free_values); + hashmap_clear(&map->map); +} + +void *strmap_put(struct strmap *map, const char *str, void *data) +{ + struct strmap_entry *entry = find_strmap_entry(map, str); + void *old = NULL; + + if (entry) { + old = entry->value; + entry->value = data; + } else { + const char *key = str; + + entry = xmalloc(sizeof(*entry)); + hashmap_entry_init(&entry->ent, strhash(str)); + + if (map->strdup_strings) + key = xstrdup(str); + entry->key = key; + entry->value = data; + hashmap_add(&map->map, &entry->ent); + } + return old; +} + +void *strmap_get(struct strmap *map, const char *str) +{ + struct strmap_entry *entry = find_strmap_entry(map, str); + return entry ? entry->value : NULL; +} + +int strmap_contains(struct strmap *map, const char *str) +{ + return find_strmap_entry(map, str) != NULL; +} -- cgit v1.2.3