return hash;
}
+/*
+ * Incorporate another chunk of data into a memihash
+ * computation.
+ */
+unsigned int memihash_cont(unsigned int hash_seed, const void *buf, size_t len)
+{
+ unsigned int hash = hash_seed;
+ unsigned char *ucbuf = (unsigned char *) buf;
+ while (len--) {
+ unsigned int c = *ucbuf++;
+ if (c >= 'a' && c <= 'z')
+ c -= 'a' - 'A';
+ hash = (hash * FNV32_PRIME) ^ c;
+ }
+ return hash;
+}
+
#define HASHMAP_INITIAL_SIZE 64
/* grow / shrink by 2^2 */
#define HASHMAP_RESIZE_BITS 2
}
static inline int entry_equals(const struct hashmap *map,
- const struct hashmap_entry *e1, const struct hashmap_entry *e2,
- const void *keydata)
+ const struct hashmap_entry *e1,
+ const struct hashmap_entry *e2,
+ const void *keydata)
{
- return (e1 == e2) || (e1->hash == e2->hash && !map->cmpfn(e1, e2, keydata));
+ return (e1 == e2) ||
+ (e1->hash == e2->hash &&
+ !map->cmpfn(map->cmpfn_data, e1, e2, keydata));
}
static inline unsigned int bucket(const struct hashmap *map,
- const struct hashmap_entry *key)
+ const struct hashmap_entry *key)
{
return key->hash & (map->tablesize - 1);
}
+int hashmap_bucket(const struct hashmap *map, unsigned int hash)
+{
+ return hash & (map->tablesize - 1);
+}
+
static void rehash(struct hashmap *map, unsigned int newsize)
{
+ /* map->table MUST NOT be NULL when this function is called */
unsigned int i, oldsize = map->tablesize;
struct hashmap_entry **oldtable = map->table;
static inline struct hashmap_entry **find_entry_ptr(const struct hashmap *map,
const struct hashmap_entry *key, const void *keydata)
{
+ /* map->table MUST NOT be NULL when this function is called */
struct hashmap_entry **e = &map->table[bucket(map, key)];
while (*e && !entry_equals(map, *e, key, keydata))
e = &(*e)->next;
return e;
}
-static int always_equal(const void *unused1, const void *unused2, const void *unused3)
+static int always_equal(const void *unused_cmp_data,
+ const struct hashmap_entry *unused1,
+ const struct hashmap_entry *unused2,
+ const void *unused_keydata)
{
return 0;
}
void hashmap_init(struct hashmap *map, hashmap_cmp_fn equals_function,
- size_t initial_size)
+ const void *cmpfn_data, size_t initial_size)
{
unsigned int size = HASHMAP_INITIAL_SIZE;
- map->size = 0;
+
+ memset(map, 0, sizeof(*map));
+
map->cmpfn = equals_function ? equals_function : always_equal;
+ map->cmpfn_data = cmpfn_data;
/* calculate initial table size and allocate the table */
initial_size = (unsigned int) ((uint64_t) initial_size * 100
while (initial_size > size)
size <<= HASHMAP_RESIZE_BITS;
alloc_table(map, size);
+
+ /*
+ * Keep track of the number of items in the map and
+ * allow the map to automatically grow as necessary.
+ */
+ map->do_count_items = 1;
+}
+
+static void free_individual_entries(struct hashmap *map, ssize_t entry_offset)
+{
+ struct hashmap_iter iter;
+ struct hashmap_entry *e;
+
+ hashmap_iter_init(map, &iter);
+ while ((e = hashmap_iter_next(&iter)))
+ /*
+ * like container_of, but using caller-calculated
+ * offset (caller being hashmap_clear_and_free)
+ */
+ free((char *)e - entry_offset);
}
-void hashmap_free(struct hashmap *map, int free_entries)
+void hashmap_partial_clear_(struct hashmap *map, ssize_t entry_offset)
{
if (!map || !map->table)
return;
- if (free_entries) {
- struct hashmap_iter iter;
- struct hashmap_entry *e;
- hashmap_iter_init(map, &iter);
- while ((e = hashmap_iter_next(&iter)))
- free(e);
- }
+ if (entry_offset >= 0) /* called by hashmap_clear_entries */
+ free_individual_entries(map, entry_offset);
+ memset(map->table, 0, map->tablesize * sizeof(struct hashmap_entry *));
+ map->shrink_at = 0;
+ map->private_size = 0;
+}
+
+void hashmap_clear_(struct hashmap *map, ssize_t entry_offset)
+{
+ if (!map || !map->table)
+ return;
+ if (entry_offset >= 0) /* called by hashmap_clear_and_free */
+ free_individual_entries(map, entry_offset);
free(map->table);
memset(map, 0, sizeof(*map));
}
-void *hashmap_get(const struct hashmap *map, const void *key, const void *keydata)
+struct hashmap_entry *hashmap_get(const struct hashmap *map,
+ const struct hashmap_entry *key,
+ const void *keydata)
{
+ if (!map->table)
+ return NULL;
return *find_entry_ptr(map, key, keydata);
}
-void *hashmap_get_next(const struct hashmap *map, const void *entry)
+struct hashmap_entry *hashmap_get_next(const struct hashmap *map,
+ const struct hashmap_entry *entry)
{
- struct hashmap_entry *e = ((struct hashmap_entry *) entry)->next;
+ struct hashmap_entry *e = entry->next;
for (; e; e = e->next)
if (entry_equals(map, entry, e, NULL))
return e;
return NULL;
}
-void hashmap_add(struct hashmap *map, void *entry)
+void hashmap_add(struct hashmap *map, struct hashmap_entry *entry)
{
- unsigned int b = bucket(map, entry);
+ unsigned int b;
+ if (!map->table)
+ alloc_table(map, HASHMAP_INITIAL_SIZE);
+
+ b = bucket(map, entry);
/* add entry */
- ((struct hashmap_entry *) entry)->next = map->table[b];
+ entry->next = map->table[b];
map->table[b] = entry;
/* fix size and rehash if appropriate */
- map->size++;
- if (map->size > map->grow_at)
- rehash(map, map->tablesize << HASHMAP_RESIZE_BITS);
+ if (map->do_count_items) {
+ map->private_size++;
+ if (map->private_size > map->grow_at)
+ rehash(map, map->tablesize << HASHMAP_RESIZE_BITS);
+ }
}
-void *hashmap_remove(struct hashmap *map, const void *key, const void *keydata)
+struct hashmap_entry *hashmap_remove(struct hashmap *map,
+ const struct hashmap_entry *key,
+ const void *keydata)
{
struct hashmap_entry *old;
- struct hashmap_entry **e = find_entry_ptr(map, key, keydata);
+ struct hashmap_entry **e;
+
+ if (!map->table)
+ return NULL;
+ e = find_entry_ptr(map, key, keydata);
if (!*e)
return NULL;
old->next = NULL;
/* fix size and rehash if appropriate */
- map->size--;
- if (map->size < map->shrink_at)
- rehash(map, map->tablesize >> HASHMAP_RESIZE_BITS);
+ if (map->do_count_items) {
+ map->private_size--;
+ if (map->private_size < map->shrink_at)
+ rehash(map, map->tablesize >> HASHMAP_RESIZE_BITS);
+ }
+
return old;
}
-void *hashmap_put(struct hashmap *map, void *entry)
+struct hashmap_entry *hashmap_put(struct hashmap *map,
+ struct hashmap_entry *entry)
{
struct hashmap_entry *old = hashmap_remove(map, entry, NULL);
hashmap_add(map, entry);
iter->next = NULL;
}
-void *hashmap_iter_next(struct hashmap_iter *iter)
+struct hashmap_entry *hashmap_iter_next(struct hashmap_iter *iter)
{
struct hashmap_entry *current = iter->next;
for (;;) {
current = iter->map->table[iter->tablepos++];
}
}
+
+struct pool_entry {
+ struct hashmap_entry ent;
+ size_t len;
+ unsigned char data[FLEX_ARRAY];
+};
+
+static int pool_entry_cmp(const void *unused_cmp_data,
+ const struct hashmap_entry *eptr,
+ const struct hashmap_entry *entry_or_key,
+ const void *keydata)
+{
+ const struct pool_entry *e1, *e2;
+
+ e1 = container_of(eptr, const struct pool_entry, ent);
+ e2 = container_of(entry_or_key, const struct pool_entry, ent);
+
+ return e1->data != keydata &&
+ (e1->len != e2->len || memcmp(e1->data, keydata, e1->len));
+}
+
+const void *memintern(const void *data, size_t len)
+{
+ static struct hashmap map;
+ struct pool_entry key, *e;
+
+ /* initialize string pool hashmap */
+ if (!map.tablesize)
+ hashmap_init(&map, pool_entry_cmp, NULL, 0);
+
+ /* lookup interned string in pool */
+ hashmap_entry_init(&key.ent, memhash(data, len));
+ key.len = len;
+ e = hashmap_get_entry(&map, &key, ent, data);
+ if (!e) {
+ /* not found: create it */
+ FLEX_ALLOC_MEM(e, data, data, len);
+ hashmap_entry_init(&e->ent, key.ent.hash);
+ e->len = len;
+ hashmap_add(&map, &e->ent);
+ }
+ return e->data;
+}
projects / platform / upstream / git.git / blobdiff