hash_table: Add new hash_table_remove function.

To allow for the removal of a single element from a hash table.

2 files changed, 21 insertions, 0 deletions

diff --git a/src/mesa/shader/hash_table.c b/src/mesa/shader/hash_table.c
index 933e300abd..f7ef366c1a 100644
--- a/src/mesa/shader/hash_table.c
+++ b/src/mesa/shader/hash_table.c
@@ -142,6 +142,23 @@ hash_table_insert(struct hash_table *ht, void *data, const void *key)
     insert_at_head(& ht->buckets[bucket], & node->link);
 }
 
+void
+hash_table_remove(struct hash_table *ht, const void *key)
+{
+    const unsigned hash_value = (*ht->hash)(key);
+    const unsigned bucket = hash_value % ht->num_buckets;
+    struct node *node;
+
+    foreach(node, & ht->buckets[bucket]) {
+       struct hash_node *hn = (struct hash_node *) node;
+
+       if ((*ht->compare)(hn->key, key) == 0) {
+	  remove_from_list(node);
+	  free(node);
+	  return;
+       }
+    }
+}
 
 unsigned
 hash_table_string_hash(const void *key)
diff --git a/src/mesa/shader/hash_table.h b/src/mesa/shader/hash_table.h
index 0552691464..228ab948ff 100644
--- a/src/mesa/shader/hash_table.h
+++ b/src/mesa/shader/hash_table.h
@@ -94,6 +94,10 @@ extern void *hash_table_find(struct hash_table *ht, const void *key);
 extern void hash_table_insert(struct hash_table *ht, void *data,
     const void *key);
 
+/**
+ * Remove a specific element from a hash table.
+ */
+extern void hash_table_remove(struct hash_table *ht, const void *key);
 
 /**
  * Compute hash value of a string