strmap: take advantage of FLEXPTR_ALLOC_STR when relevant

By default, we do not use a mempool and strdup_strings is true; in this
case, we can avoid both an extra allocation and an extra free by just
over-allocating for the strmap_entry leaving enough space at the end to
copy the key.  FLEXPTR_ALLOC_STR exists for exactly this purpose, so
make use of it.

Also, adjust the case when we are using a memory pool and strdup_strings
is true to just do one allocation from the memory pool instead of two so
that the strmap_clear() and strmap_remove() code can just avoid freeing
the key in all cases.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Elijah Newren 2020-11-11 20:02:19 +00:00 committed by Junio C Hamano
parent a208ec1f0b
commit 23a276a9c4
2 changed files with 20 additions and 16 deletions

View File

@ -59,11 +59,8 @@ static void strmap_free_entries_(struct strmap *map, int free_values)
hashmap_for_each_entry(&map->map, &iter, e, ent) {
if (free_values)
free(e->value);
if (!map->pool) {
if (map->strdup_strings)
free((char*)e->key);
if (!map->pool)
free(e);
}
}
}
@ -84,16 +81,25 @@ static struct strmap_entry *create_entry(struct strmap *map,
void *data)
{
struct strmap_entry *entry;
const char *key = str;
entry = map->pool ? mem_pool_alloc(map->pool, sizeof(*entry))
: xmalloc(sizeof(*entry));
if (map->strdup_strings) {
if (!map->pool) {
FLEXPTR_ALLOC_STR(entry, key, str);
} else {
size_t len = st_add(strlen(str), 1); /* include NUL */
entry = mem_pool_alloc(map->pool,
st_add(sizeof(*entry), len));
memcpy(entry + 1, str, len);
entry->key = (void *)(entry + 1);
}
} else if (!map->pool) {
entry = xmalloc(sizeof(*entry));
} else {
entry = mem_pool_alloc(map->pool, sizeof(*entry));
}
hashmap_entry_init(&entry->ent, strhash(str));
if (map->strdup_strings)
key = map->pool ? mem_pool_strdup(map->pool, str)
: xstrdup(str);
entry->key = key;
if (!map->strdup_strings)
entry->key = str;
entry->value = data;
return entry;
}
@ -139,11 +145,8 @@ void strmap_remove(struct strmap *map, const char *str, int free_value)
return;
if (free_value)
free(ret->value);
if (!map->pool) {
if (map->strdup_strings)
free((char*)ret->key);
if (!map->pool)
free(ret);
}
}
void strintmap_incr(struct strintmap *map, const char *str, intptr_t amt)

View File

@ -14,6 +14,7 @@ struct strmap_entry {
struct hashmap_entry ent;
const char *key;
void *value;
/* strmap_entry may be allocated extra space to store the key at end */
};
int cmp_strmap_entry(const void *hashmap_cmp_fn_data,