util/hash_table: Add _mesa_hash_table_init function

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

2 files changed, 34 insertions, 13 deletions

diff --git a/src/util/hash_table.c b/src/util/hash_table.c
index fc152f84a4d..4f510612a8f 100644
--- 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;
diff --git a/src/util/hash_table.h b/src/util/hash_table.h
index d89fc1dc1c8..40acda1fd1e 100644
--- a/src/util/hash_table.h
+++ b/src/util/hash_table.h
@@ -62,6 +62,14 @@ _mesa_hash_table_create(void *mem_ctx,
                         uint32_t (*key_hash_function)(const void *key),
                         bool (*key_equals_function)(const void *a,
                                                     const void *b));
+
+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));
+
 struct hash_table *
 _mesa_hash_table_clone(struct hash_table *src, void *dst_mem_ctx);
 void _mesa_hash_table_destroy(struct hash_table *ht,