util: Helper to create sets and hashes with pointer keys

[mesa.git] / src / util / hash_table.c

diff --git a/src/util/hash_table.c b/src/util/hash_table.c
index fc152f84a4dde7d7a2c7d1229234d9bde2eef149..57a5f247edcec89be20374b4dfbed320c9f36390 100644 (file)
--- a/src/util/hash_table.c
+++ b/src/util/hash_table.c
@@ -110,6 +110,27 @@ entry_is_present(const struct hash_table *ht, struct hash_entry *entry)
    return entry->key != NULL && entry->key != ht->deleted_key;
 }
 
+bool
+_mesa_hash_table_init(struct hash_table *ht,
+                      void *mem_ctx,
+                      uint32_t (*key_hash_function)(const void *key),
+                      bool (*key_equals_function)(const void *a,
+                                                  const void *b))
+{
+   ht->size_index = 0;
+   ht->size = hash_sizes[ht->size_index].size;
+   ht->rehash = hash_sizes[ht->size_index].rehash;
+   ht->max_entries = hash_sizes[ht->size_index].max_entries;
+   ht->key_hash_function = key_hash_function;
+   ht->key_equals_function = key_equals_function;
+   ht->table = rzalloc_array(mem_ctx, struct hash_entry, ht->size);
+   ht->entries = 0;
+   ht->deleted_entries = 0;
+   ht->deleted_key = &deleted_key_value;
+
+   return ht->table != NULL;
+}
+
 struct hash_table *
 _mesa_hash_table_create(void *mem_ctx,
                         uint32_t (*key_hash_function)(const void *key),
@@ -118,22 +139,14 @@ _mesa_hash_table_create(void *mem_ctx,
 {
    struct hash_table *ht;
 
+   /* mem_ctx is used to allocate the hash table, but the hash table is used
+    * to allocate all of the suballocations.
+    */
    ht = ralloc(mem_ctx, struct hash_table);
    if (ht == NULL)
       return NULL;
 
-   ht->size_index = 0;
-   ht->size = hash_sizes[ht->size_index].size;
-   ht->rehash = hash_sizes[ht->size_index].rehash;
-   ht->max_entries = hash_sizes[ht->size_index].max_entries;
-   ht->key_hash_function = key_hash_function;
-   ht->key_equals_function = key_equals_function;
-   ht->table = rzalloc_array(ht, struct hash_entry, ht->size);
-   ht->entries = 0;
-   ht->deleted_entries = 0;
-   ht->deleted_key = &deleted_key_value;
-
-   if (ht->table == NULL) {
+   if (!_mesa_hash_table_init(ht, ht, key_hash_function, key_equals_function)) {
       ralloc_free(ht);
       return NULL;
    }
@@ -287,7 +300,7 @@ _mesa_hash_table_rehash(struct hash_table *ht, unsigned new_size_index)
    if (new_size_index >= ARRAY_SIZE(hash_sizes))
       return;
 
-   table = rzalloc_array(ht, struct hash_entry,
+   table = rzalloc_array(ralloc_parent(ht->table), struct hash_entry,
                          hash_sizes[new_size_index].size);
    if (table == NULL)
       return;
@@ -534,6 +547,16 @@ _mesa_key_pointer_equal(const void *a, const void *b)
    return a == b;
 }
 
+/**
+ * Helper to create a hash table with pointer keys.
+ */
+struct hash_table *
+_mesa_pointer_hash_table_create(void *mem_ctx)
+{
+   return _mesa_hash_table_create(mem_ctx, _mesa_hash_pointer,
+                                  _mesa_key_pointer_equal);
+}
+
 /**
  * Hash table wrapper which supports 64-bit keys.
  *