*
* 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!
* };
*
* if (!strcmp("print_all_by_key", action)) {
* struct long2string k, *e;
- * hashmap_entry_init(&k->ent, memhash(&key, sizeof(long)));
+ * hashmap_entry_init(&k.ent, memhash(&key, sizeof(long)));
* k.key = key;
*
* flags &= ~COMPARE_VALUE;
- * e = hashmap_get_entry(&map, &k, NULL, struct long2string, ent);
+ * e = hashmap_get_entry(&map, &k, ent, NULL);
* if (e) {
* printf("first: %ld %s\n", e->key, e->value);
* while ((e = hashmap_get_next_entry(&map, e,
*
* if (!strcmp("has_exact_match_no_heap_alloc", action)) {
* struct long2string k;
- * hashmap_entry_init(&k->ent, 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->ent, value) ? "" : "not ");
+ * 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.
*/
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
+ */
+#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
*/
-void hashmap_free(struct hashmap *map, int free_entries);
+#define hashmap_free_entries(map, type, member) \
+ hashmap_free_(map, offsetof(type, member));
/* hashmap_entry functions */
struct hashmap_entry *hashmap_put(struct hashmap *map,
struct hashmap_entry *entry);
-#define hashmap_put_entry(map, keyvar, type, member) \
- container_of_or_null(hashmap_put(map, &(keyvar)->member), type, member)
+/*
+ * 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
const struct hashmap_entry *key,
const void *keydata);
-#define hashmap_remove_entry(map, keyvar, keydata, type, member) \
- container_of_or_null(hashmap_remove(map, &(keyvar)->member, keydata), \
- type, member)
+/*
+ * 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.
return hashmap_iter_next(iter);
}
-#define hashmap_iter_next_entry(iter, type, member) \
- container_of_or_null(hashmap_iter_next(iter), type, member)
-
+/*
+ * 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)
-#define hashmap_for_each_entry(map, iter, var, type, member) \
- for (var = hashmap_iter_first_entry(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(iter, type, member))
+ 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 of @type
- * @member is the name of the "struct hashmap_entry" field in @type
+ * 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, keydata, type, member) \
- container_of_or_null(hashmap_get(map, &(keyvar)->member, keydata), \
- type, 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 @type pointer to @var, or NULL if not found.
- * @var is a pointer of @type
- * @member is the name of the "struct hashmap_entry" field in @type
+ * 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, type, member) \
- container_of_or_null(hashmap_get_next(map, &(var)->member), \
- type, member)
+#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, type, member) \
+#define hashmap_for_each_entry_from(map, var, member) \
for (; \
var; \
- var = hashmap_get_next_entry(map, var, type, member))
+ var = hashmap_get_next_entry(map, var, member))
/*
* Disable item counting and automatic rehashing when adding/removing items.