Mesa (glsl2): hash_table: Add new hash_table_remove function.

[Ian Romanick]

Module: Mesa
Branch: glsl2
Commit: d4f239de6e988a59d4ba3783ea325aa1552c3f5a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=d4f239de6e988a59d4ba3783ea325aa1552c3f5a

Author: Carl Worth <cworth at cworth.org>
Date:   Mon Jul 19 18:01:43 2010 -0700

hash_table: Add new hash_table_remove function.

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

---

 src/mesa/shader/hash_table.c |   17 +++++++++++++++++
 src/mesa/shader/hash_table.h |    4 ++++
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/src/mesa/shader/hash_table.c b/src/mesa/shader/hash_table.c
index 933e300..f7ef366 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 0552691..228ab94 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