Merge branch 'en/strmap'

A specialization of hashmap that uses a string as key has been
introduced.  Hopefully it will see wider use over time.

* en/strmap:
  shortlog: use strset from strmap.h
  Use new HASHMAP_INIT macro to simplify hashmap initialization
  strmap: take advantage of FLEXPTR_ALLOC_STR when relevant
  strmap: enable allocations to come from a mem_pool
  strmap: add a strset sub-type
  strmap: split create_entry() out of strmap_put()
  strmap: add functions facilitating use as a string->int map
  strmap: enable faster clearing and reusing of strmaps
  strmap: add more utility functions
  strmap: new utility functions
  hashmap: provide deallocation function names
  hashmap: introduce a new hashmap_partial_clear()
  hashmap: allow re-use after hashmap_free()
  hashmap: adjust spacing to fix argument alignment
  hashmap: add usage documentation explaining hashmap_free[_entries]()

1 files changed, 51 insertions, 23 deletions

diff --git a/hashmap.c b/hashmap.c
index 09813e1a46..5009471800 100644
--- a/hashmap.c
+++ b/hashmap.c
@@ -92,8 +92,9 @@ static void alloc_table(struct hashmap *map, unsigned int size)
 }
 
 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 &&
@@ -101,7 +102,7 @@ static inline int entry_equals(const struct hashmap *map,
 }
 
 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);
 }
@@ -113,6 +114,7 @@ int hashmap_bucket(const struct hashmap *map, unsigned int hash)
 
 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;
 
@@ -133,6 +135,7 @@ static void rehash(struct hashmap *map, unsigned int newsize)
 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;
@@ -148,7 +151,7 @@ static int always_equal(const void *unused_cmp_data,
 }
 
 void hashmap_init(struct hashmap *map, hashmap_cmp_fn equals_function,
-		const void *cmpfn_data, size_t initial_size)
+		  const void *cmpfn_data, size_t initial_size)
 {
 	unsigned int size = HASHMAP_INITIAL_SIZE;
 
@@ -171,22 +174,37 @@ void hashmap_init(struct hashmap *map, hashmap_cmp_fn equals_function,
 	map->do_count_items = 1;
 }
 
-void hashmap_free_(struct hashmap *map, ssize_t entry_offset)
+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_partial_clear_(struct hashmap *map, ssize_t entry_offset)
 {
 	if (!map || !map->table)
 		return;
-	if (entry_offset >= 0) { /* called by hashmap_free_entries */
-		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_free_entries)
-			 */
-			free((char *)e - entry_offset);
-	}
+	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));
 }
@@ -195,11 +213,13 @@ 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);
 }
 
 struct hashmap_entry *hashmap_get_next(const struct hashmap *map,
-			const struct hashmap_entry *entry)
+				       const struct hashmap_entry *entry)
 {
 	struct hashmap_entry *e = entry->next;
 	for (; e; e = e->next)
@@ -210,8 +230,12 @@ struct hashmap_entry *hashmap_get_next(const struct hashmap *map,
 
 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 */
 	entry->next = map->table[b];
 	map->table[b] = entry;
@@ -225,11 +249,15 @@ void hashmap_add(struct hashmap *map, struct hashmap_entry *entry)
 }
 
 struct hashmap_entry *hashmap_remove(struct hashmap *map,
-					const struct hashmap_entry *key,
-					const void *keydata)
+				     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;
 
@@ -249,7 +277,7 @@ struct hashmap_entry *hashmap_remove(struct hashmap *map,
 }
 
 struct hashmap_entry *hashmap_put(struct hashmap *map,
-				struct hashmap_entry *entry)
+				  struct hashmap_entry *entry)
 {
 	struct hashmap_entry *old = hashmap_remove(map, entry, NULL);
 	hashmap_add(map, entry);