hashmap: hashmap_{put,remove} return hashmap_entry *

And add *_entry variants to perform container_of as necessary
to simplify most callers.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

hashmap.c

@@ -219,7 +219,8 @@ void hashmap_add(struct hashmap *map, struct hashmap_entry *entry)
 	}
 }
 
-void *hashmap_remove(struct hashmap *map, const struct hashmap_entry *key,
+struct hashmap_entry *hashmap_remove(struct hashmap *map,
+					const struct hashmap_entry *key,
 					const void *keydata)
 {
 	struct hashmap_entry *old;
@@ -242,7 +243,8 @@ void *hashmap_remove(struct hashmap *map, const struct hashmap_entry *key,
 	return old;
 }
 
-void *hashmap_put(struct hashmap *map, struct hashmap_entry *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);

hashmap.h

@@ -349,7 +349,11 @@ void hashmap_add(struct hashmap *map, struct hashmap_entry *entry);
  * `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, struct hashmap_entry *entry);
+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)
 
 /*
  * Removes a hashmap entry matching the specified key. If the hashmap contains
@@ -358,9 +362,14 @@ void *hashmap_put(struct hashmap *map, struct hashmap_entry *entry);
  *
  * Argument explanation is the same as in `hashmap_get`.
  */
-void *hashmap_remove(struct hashmap *map, const struct hashmap_entry *key,
+struct hashmap_entry *hashmap_remove(struct hashmap *map,
+					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)
+
 /*
  * Returns the `bucket` an entry is stored in.
  * Useful for multithreaded read access.

range-diff.c

@@ -229,7 +229,9 @@ static void find_exact_matches(struct string_list *a, struct string_list *b)
 		util->patch = b->items[i].string;
 		util->diff = util->patch + util->diff_offset;
 		hashmap_entry_init(&util->e, strhash(util->diff));
-		other = hashmap_remove(&map, &util->e, NULL);
+		other = hashmap_remove_entry(&map, util, NULL,
+					struct patch_util,
+					e /* member name */);
 		if (other) {
 			if (other->matching >= 0)
 				BUG("already assigned!");

remote.c

@@ -162,7 +162,8 @@ static struct remote *make_remote(const char *name, int len)
 	remotes[remotes_nr++] = ret;
 
 	hashmap_entry_init(&ret->ent, lookup_entry.hash);
-	replaced = hashmap_put(&remotes_hash, &ret->ent);
+	replaced = hashmap_put_entry(&remotes_hash, ret, struct remote,
+					ent /* member name */);
 	assert(replaced == NULL);  /* no previous entry overwritten */
 	return ret;
 }

submodule-config.c

@@ -141,7 +141,9 @@ static void cache_remove_path(struct submodule_cache *cache,
 	struct submodule_entry *removed;
 	hashmap_entry_init(&e.ent, hash);
 	e.config = submodule;
-	removed = hashmap_remove(&cache->for_path, &e.ent, NULL);
+	removed = hashmap_remove_entry(&cache->for_path, &e, NULL,
+					struct submodule_entry,
+					ent /* member name */);
 	free(removed);
 }
 

t/helper/test-hashmap.c

@@ -189,7 +189,9 @@ int cmd__hashmap(int argc, const char **argv)
 			entry = alloc_test_entry(hash, p1, p2);
 
 			/* add / replace entry */
-			entry = hashmap_put(&map, &entry->ent);
+			entry = hashmap_put_entry(&map, entry,
+						struct test_entry,
+						ent /* member name */);
 
 			/* print and free replaced entry, if any */
 			puts(entry ? get_value(entry) : "NULL");
@@ -212,10 +214,13 @@ int cmd__hashmap(int argc, const char **argv)
 
 			/* setup static key */
 			struct hashmap_entry key;
+			struct hashmap_entry *rm;
 			hashmap_entry_init(&key, hash);
 
 			/* remove entry from hashmap */
-			entry = hashmap_remove(&map, &key, p1);
+			rm = hashmap_remove(&map, &key, p1);
+			entry = rm ? container_of(rm, struct test_entry, ent)
+					: NULL;
 
 			/* print result and free entry*/
 			puts(entry ? get_value(entry) : "NULL");