From a889928d85ac8ba7e1a7fe15393858a9422cf750 Mon Sep 17 00:00:00 2001
From: Zack Rusin <zack@tungstengraphics.com>
Date: Thu, 13 Mar 2008 16:41:12 -0400
Subject: add a way of removing an exact iterator from the hash

---
 src/gallium/auxiliary/cso_cache/cso_hash.c | 25 ++++++++++++++++++++++---
 src/gallium/auxiliary/cso_cache/cso_hash.h | 16 ++++++++++++++--
 2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/src/gallium/auxiliary/cso_cache/cso_hash.c b/src/gallium/auxiliary/cso_cache/cso_hash.c
index 5cad5d3be7..ddce3822f7 100644
--- a/src/gallium/auxiliary/cso_cache/cso_hash.c
+++ b/src/gallium/auxiliary/cso_cache/cso_hash.c
@@ -99,7 +99,7 @@ static void *cso_data_allocate_node(struct cso_hash_data *hash)
    return MALLOC(hash->nodeSize);
 }
 
-static void cso_data_free_node(struct cso_node *node)
+static void cso_free_node(struct cso_node *node)
 {
    FREE(node);
 }
@@ -248,7 +248,7 @@ void cso_hash_delete(struct cso_hash *hash)
       struct cso_node *cur = *bucket++;
       while (cur != e_for_x) {
          struct cso_node *next = cur->next;
-         cso_data_free_node(cur);
+         cso_free_node(cur);
          cur = next;
       }
    }
@@ -367,7 +367,7 @@ void * cso_hash_take(struct cso_hash *hash,
    if (*node != hash->data.e) {
       void *t = (*node)->value;
       struct cso_node *next = (*node)->next;
-      cso_data_free_node(*node);
+      cso_free_node(*node);
       *node = next;
       --hash->data.d->size;
       cso_data_has_shrunk(hash->data.d);
@@ -393,3 +393,22 @@ int cso_hash_size(struct cso_hash *hash)
 {
    return hash->data.d->size;
 }
+
+struct cso_hash_iter cso_hash_erase(struct cso_hash *hash, struct cso_hash_iter iter)
+{
+   struct cso_hash_iter ret = iter;
+   struct cso_node *node = iter.node;
+   struct cso_node **node_ptr;
+
+   if (node == hash->data.e)
+      return iter;
+
+   ret = cso_hash_iter_next(ret);
+   node_ptr = (struct cso_node**)(&hash->data.d->buckets[node->key % hash->data.d->numBuckets]);
+   while (*node_ptr != node)
+      node_ptr = &(*node_ptr)->next;
+   *node_ptr = node->next;
+   cso_free_node(node);
+   --hash->data.d->size;
+   return ret;
+}
diff --git a/src/gallium/auxiliary/cso_cache/cso_hash.h b/src/gallium/auxiliary/cso_cache/cso_hash.h
index a3a65b68c8..73c4742006 100644
--- a/src/gallium/auxiliary/cso_cache/cso_hash.h
+++ b/src/gallium/auxiliary/cso_cache/cso_hash.h
@@ -68,14 +68,26 @@ int              cso_hash_size(struct cso_hash *hash);
 
 
 /**
- * Create a list of objects and just add entry with the same key to the list.
+ * Adds a data with the given key to the hash. If entry with the given
+ * key is already in the hash, this current entry is instered before it
+ * in the collision list.
+ * Function returns iterator pointing to the inserted item in the hash.
  */
 struct cso_hash_iter cso_hash_insert(struct cso_hash *hash, unsigned key,
                                      void *data);
+/**
+ * Removes the item pointed to by the current iterator from the hash.
+ * Note that the data itself is not erased and if it was a malloc'ed pointer
+ * it will have to be freed after calling this function by the callee.
+ * Function returns iterator pointing to the item after the removed one in
+ * the hash.
+ */
+struct cso_hash_iter cso_hash_erase(struct cso_hash *hash, struct cso_hash_iter iter);
 
 void  *cso_hash_take(struct cso_hash *hash, unsigned key);
 
 
+
 struct cso_hash_iter cso_hash_first_node(struct cso_hash *hash);
 
 /**
@@ -97,7 +109,7 @@ struct cso_hash_iter cso_hash_iter_prev(struct cso_hash_iter iter);
  * Convenience routine to iterate over the collision list while doing a memory 
  * comparison to see which entry in the list is a direct copy of our template
  * and returns that entry.
- */ 
+ */
 void *cso_hash_find_data_from_template( struct cso_hash *hash,
 				        unsigned hash_key, 
 				        void *templ,
-- 
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