*
* struct hashmap map;
* struct long2string {
- * struct hashmap_entry ent; // must be the first member!
+ * struct hashmap_entry ent;
* long key;
* char value[FLEX_ARRAY]; // be careful with allocating on stack!
* };
* #define COMPARE_VALUE 1
*
* static int long2string_cmp(const void *hashmap_cmp_fn_data,
- * const struct long2string *e1,
- * const struct long2string *e2,
+ * const struct hashmap_entry *eptr,
+ * const struct hashmap_entry *entry_or_key,
* const void *keydata)
* {
* const char *string = keydata;
* unsigned flags = *(unsigned *)hashmap_cmp_fn_data;
+ * const struct long2string *e1, *e2;
+ *
+ * e1 = container_of(eptr, const struct long2string, ent);
+ * e2 = container_of(entry_or_key, const struct long2string, ent);
*
* if (flags & COMPARE_VALUE)
* return e1->key != e2->key ||
* char value[255], action[32];
* unsigned flags = 0;
*
- * hashmap_init(&map, (hashmap_cmp_fn) long2string_cmp, &flags, 0);
+ * hashmap_init(&map, long2string_cmp, &flags, 0);
*
* while (scanf("%s %ld %s", action, &key, value)) {
*
* if (!strcmp("add", action)) {
* struct long2string *e;
* FLEX_ALLOC_STR(e, value, value);
- * hashmap_entry_init(e, memhash(&key, sizeof(long)));
+ * hashmap_entry_init(&e->ent, memhash(&key, sizeof(long)));
* e->key = key;
- * hashmap_add(&map, e);
+ * hashmap_add(&map, &e->ent);
* }
*
* if (!strcmp("print_all_by_key", action)) {
* struct long2string k, *e;
- * hashmap_entry_init(&k, memhash(&key, sizeof(long)));
+ * hashmap_entry_init(&k->ent, memhash(&key, sizeof(long)));
* k.key = key;
*
* flags &= ~COMPARE_VALUE;
- * e = hashmap_get(&map, &k, NULL);
+ * e = hashmap_get_entry(&map, &k, ent, NULL);
* if (e) {
* printf("first: %ld %s\n", e->key, e->value);
- * while ((e = hashmap_get_next(&map, e)))
+ * while ((e = hashmap_get_next_entry(&map, e,
+ * struct long2string, ent))) {
* printf("found more: %ld %s\n", e->key, e->value);
+ * }
* }
* }
*
* if (!strcmp("has_exact_match", action)) {
* struct long2string *e;
* FLEX_ALLOC_STR(e, value, value);
- * hashmap_entry_init(e, memhash(&key, sizeof(long)));
+ * hashmap_entry_init(&e->ent, memhash(&key, sizeof(long)));
* e->key = key;
*
* flags |= COMPARE_VALUE;
- * printf("%sfound\n", hashmap_get(&map, e, NULL) ? "" : "not ");
+ * printf("%sfound\n",
+ * hashmap_get(&map, &e->ent, NULL) ? "" : "not ");
* free(e);
* }
*
* if (!strcmp("has_exact_match_no_heap_alloc", action)) {
* struct long2string k;
- * hashmap_entry_init(&k, memhash(&key, sizeof(long)));
+ * hashmap_entry_init(&k->ent, memhash(&key, sizeof(long)));
* k.key = key;
*
* flags |= COMPARE_VALUE;
- * printf("%sfound\n", hashmap_get(&map, &k, value) ? "" : "not ");
+ * printf("%sfound\n",
+ * hashmap_get(&map, &k->ent, value) ? "" : "not ");
* }
*
* if (!strcmp("end", action)) {
- * hashmap_free(&map, 1);
+ * hashmap_free_entries(&map, struct long2string, ent);
* break;
* }
* }
/*
* struct hashmap_entry is an opaque structure representing an entry in the
- * hash table, which must be used as first member of user data structures.
+ * hash table.
* Ideally it should be followed by an int-sized member to prevent unused
* memory on 64-bit systems due to alignment.
*/
* The `hashmap_cmp_fn_data` entry is the pointer given in the init function.
*/
typedef int (*hashmap_cmp_fn)(const void *hashmap_cmp_fn_data,
- const void *entry, const void *entry_or_key,
+ const struct hashmap_entry *entry,
+ const struct hashmap_entry *entry_or_key,
const void *keydata);
/*
const void *equals_function_data,
size_t initial_size);
+/* internal function for freeing hashmap */
+void hashmap_free_(struct hashmap *map, ssize_t offset);
+
/*
- * Frees a hashmap structure and allocated memory.
- *
- * If `free_entries` is true, each hashmap_entry in the map is freed as well
- * using stdlibs free().
+ * Frees a hashmap structure and allocated memory, leaves entries undisturbed
*/
-void hashmap_free(struct hashmap *map, int 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
+ */
+#define hashmap_free_entries(map, type, member) \
+ hashmap_free_(map, offsetof(type, member));
/* hashmap_entry functions */
* your structure was allocated with xmalloc(), you can just free(3) it,
* and if it is on stack, you can just let it go out of scope).
*/
-static inline void hashmap_entry_init(void *entry, unsigned int hash)
+static inline void hashmap_entry_init(struct hashmap_entry *e,
+ unsigned int hash)
{
- struct hashmap_entry *e = entry;
e->hash = hash;
e->next = NULL;
}
* If an entry with matching hash code is found, `key` and `keydata` are passed
* to `hashmap_cmp_fn` to decide whether the entry matches the key.
*/
-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);
/*
* Returns the hashmap entry for the specified hash code and key data,
* `entry_or_key` parameter of `hashmap_cmp_fn` points to a hashmap_entry
* structure that should not be used in the comparison.
*/
-static inline void *hashmap_get_from_hash(const struct hashmap *map,
- unsigned int hash,
- const void *keydata)
+static inline struct hashmap_entry *hashmap_get_from_hash(
+ const struct hashmap *map,
+ unsigned int hash,
+ const void *keydata)
{
struct hashmap_entry key;
hashmap_entry_init(&key, hash);
* `entry` is the hashmap_entry to start the search from, obtained via a previous
* call to `hashmap_get` or `hashmap_get_next`.
*/
-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);
/*
* Adds a hashmap entry. This allows to add duplicate entries (i.e.
* `map` is the hashmap structure.
* `entry` is the entry to add.
*/
-void hashmap_add(struct hashmap *map, void *entry);
+void hashmap_add(struct hashmap *map, struct hashmap_entry *entry);
/*
* Adds or replaces a hashmap entry. If the hashmap contains duplicate
* `entry` is the entry to add or replace.
* Returns the replaced entry, or NULL if not found (i.e. the entry was added).
*/
-void *hashmap_put(struct hashmap *map, void *entry);
+struct hashmap_entry *hashmap_put(struct hashmap *map,
+ struct hashmap_entry *entry);
+
+/*
+ * Adds or replaces a hashmap entry contained within @keyvar,
+ * where @keyvar is a pointer to a struct containing a
+ * "struct hashmap_entry" @member.
+ *
+ * Returns the replaced pointer which is of the same type as @keyvar,
+ * or NULL if not found.
+ */
+#define hashmap_put_entry(map, keyvar, member) \
+ container_of_or_null_offset(hashmap_put(map, &(keyvar)->member), \
+ OFFSETOF_VAR(keyvar, member))
/*
* Removes a hashmap entry matching the specified key. If the hashmap contains
*
* Argument explanation is the same as in `hashmap_get`.
*/
-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);
+
+/*
+ * Removes a hashmap entry contained within @keyvar,
+ * where @keyvar is a pointer to a struct containing a
+ * "struct hashmap_entry" @member.
+ *
+ * See `hashmap_get` for an explanation of @keydata
+ *
+ * Returns the replaced pointer which is of the same type as @keyvar,
+ * or NULL if not found.
+ */
+#define hashmap_remove_entry(map, keyvar, member, keydata) \
+ container_of_or_null_offset( \
+ hashmap_remove(map, &(keyvar)->member, keydata), \
+ OFFSETOF_VAR(keyvar, member))
/*
* Returns the `bucket` an entry is stored in.
void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter);
/* Returns the next hashmap_entry, or NULL if there are no more entries. */
-void *hashmap_iter_next(struct hashmap_iter *iter);
+struct hashmap_entry *hashmap_iter_next(struct hashmap_iter *iter);
/* Initializes the iterator and returns the first entry, if any. */
-static inline void *hashmap_iter_first(struct hashmap *map,
+static inline struct hashmap_entry *hashmap_iter_first(struct hashmap *map,
struct hashmap_iter *iter)
{
hashmap_iter_init(map, iter);
return hashmap_iter_next(iter);
}
+/*
+ * returns the first entry in @map using @iter, where the entry is of
+ * @type (e.g. "struct foo") and @member is the name of the
+ * "struct hashmap_entry" in @type
+ */
+#define hashmap_iter_first_entry(map, iter, type, member) \
+ container_of_or_null(hashmap_iter_first(map, iter), type, member)
+
+/* internal macro for hashmap_for_each_entry */
+#define hashmap_iter_next_entry_offset(iter, offset) \
+ container_of_or_null_offset(hashmap_iter_next(iter), offset)
+
+/* internal macro for hashmap_for_each_entry */
+#define hashmap_iter_first_entry_offset(map, iter, offset) \
+ container_of_or_null_offset(hashmap_iter_first(map, iter), offset)
+
+/*
+ * iterate through @map using @iter, @var is a pointer to a type
+ * containing a @member which is a "struct hashmap_entry"
+ */
+#define hashmap_for_each_entry(map, iter, var, member) \
+ for (var = hashmap_iter_first_entry_offset(map, iter, \
+ OFFSETOF_VAR(var, member)); \
+ var; \
+ var = hashmap_iter_next_entry_offset(iter, \
+ OFFSETOF_VAR(var, member)))
+
+/*
+ * returns a pointer of type matching @keyvar, or NULL if nothing found.
+ * @keyvar is a pointer to a struct containing a
+ * "struct hashmap_entry" @member.
+ */
+#define hashmap_get_entry(map, keyvar, member, keydata) \
+ container_of_or_null_offset( \
+ hashmap_get(map, &(keyvar)->member, keydata), \
+ OFFSETOF_VAR(keyvar, member))
+
+#define hashmap_get_entry_from_hash(map, hash, keydata, type, member) \
+ container_of_or_null(hashmap_get_from_hash(map, hash, keydata), \
+ type, member)
+/*
+ * returns the next equal pointer to @var, or NULL if not found.
+ * @var is a pointer of any type containing "struct hashmap_entry"
+ * @member is the name of the "struct hashmap_entry" field
+ */
+#define hashmap_get_next_entry(map, var, member) \
+ container_of_or_null_offset(hashmap_get_next(map, &(var)->member), \
+ OFFSETOF_VAR(var, member))
+
+/*
+ * iterate @map starting from @var, where @var is a pointer of @type
+ * and @member is the name of the "struct hashmap_entry" field in @type
+ */
+#define hashmap_for_each_entry_from(map, var, member) \
+ for (; \
+ var; \
+ var = hashmap_get_next_entry(map, var, member))
+
/*
* Disable item counting and automatic rehashing when adding/removing items.
*
projects / thirdparty / git.git / blobdiff