From 23a276a9c4c8945aadbc323e12c970816eb43c27 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Wed, 11 Nov 2020 20:02:19 +0000 Subject: [PATCH] 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 Signed-off-by: Junio C Hamano --- strmap.c | 35 +++++++++++++++++++---------------- strmap.h | 1 + 2 files changed, 20 insertions(+), 16 deletions(-) diff --git a/strmap.c b/strmap.c index 139afb9d4b..4fb9f6100e 100644 --- a/strmap.c +++ b/strmap.c @@ -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) diff --git a/strmap.h b/strmap.h index 8745b7ceb1..c4c104411b 100644 --- a/strmap.h +++ b/strmap.h @@ -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,