Changeset 892022a1 in mainline

Timestamp:

2011-10-07T12:42:11Z (13 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

f51b1d3

Parents:

f98bec0f

Message:

hash table improvements cherrypicked from lp:~helenos-nicf/helenos/nicf

Location:

uspace/lib/c

Files:

• generic/adt/hash_table.c (modified) (2 diffs)
• include/adt/hash_table.h (modified) (1 diff)

uspace/lib/c/generic/adt/hash_table.c

@@ -76 +76 @@
         
         return true;
+}
+
+/** Remove all elements from the hash table
+ *
+ * @param h Hash table to be cleared
+ */
+void hash_table_clear(hash_table_t *h)
+{
+        for (hash_count_t chain = 0; chain < h->entries; ++chain) {
+                link_t *cur;
+                link_t *next;
+                
+                for (cur = h->entry[chain].head.next;
+                    cur != &h->entry[chain].head;
+                    cur = next) {
+                        next = cur->next;
+                        list_remove(cur);
+                        h->op->remove_callback(cur);
+                }
+        }
 }
 
@@ -198 +218 @@
  */
 void hash_table_apply(hash_table_t *h, void (*f)(link_t *, void *), void *arg)
-{
-        hash_index_t bucket;
-        
-        for (bucket = 0; bucket < h->entries; bucket++) {
-                list_foreach(h->entry[bucket], cur) {
+{       
+        for (hash_index_t bucket = 0; bucket < h->entries; bucket++) {
+                link_t *cur;
+                link_t *next;
+
+                for (cur = h->entry[bucket].head.next; cur != &h->entry[bucket].head;
+                    cur = next) {
+                        /*
+                         * The next pointer must be stored prior to the functor
+                         * call to allow using destructor as the functor (the
+                         * free function could overwrite the cur->next pointer).
+                         */
+                        next = cur->next;
                         f(cur, arg);
                 }

uspace/lib/c/include/adt/hash_table.h

@@ -86 +86 @@
 extern bool hash_table_create(hash_table_t *, hash_count_t, hash_count_t,
     hash_table_operations_t *);
+extern void hash_table_clear(hash_table_t *);
 extern void hash_table_insert(hash_table_t *, unsigned long [], link_t *);
 extern link_t *hash_table_find(hash_table_t *, unsigned long []);