Add iterator API

include/ucore/htable.h

@@ -39,6 +39,15 @@ struct UHTable {
     struct UHNode **buckets;
 };
 
+/** Iterator for the iterator API */
+struct UHIter {
+    //internal fields
+    struct UHNode **it;
+    struct UHNode **next;
+    size_t cur_bucket;
+    size_t cur_hash;
+};
+
 /**
  * Initialize a hash table.
  * @param table hash table to initialize
@@ -246,4 +255,32 @@ void uc_htable_remove(struct UHTable *table, struct UHNode *node);
 int uc_htable_resize(struct UHTable *table, size_t buckets);
 
 
+/** Get the first node with the given hash.
+ *  
+ *  @param table table
+ *  @param iter opaque iterator
+ *  @param hash hash to find
+ *  @return the first node found or NULL
+ */
+struct UHNode *uc_htable_iter_first_hash(struct UHTable *table,
+                                         struct UHIter *iter, size_t hash);
+/** Get the next node with the given hash, the iterator
+ * must previously have been passed to uc_htable_iter_first_hash
+ * which returned a non-NULL value
+ *  
+ *  @param iter opaque iterator
+ *  @return the next node found or NULL
+ */
+struct UHNode *uc_htable_iter_next_hash(struct UHIter *iter);
+
+/** Remove the node pointed to by the current iterator,
+ * uc_htable_iter_first_hash or uc_htable_iter_next_hash
+ * must previously have returned non-NULL. The node
+ * returned by the previous call is the one removed.
+ * It is safe to continue iterating after this
+ *
+ * @param iter indicated node to remove
+ */
+void uc_htable_iter_remove(struct UHIter *iter);
+
 #endif

src/htable.c

@@ -171,3 +171,47 @@ int uc_htable_resize(struct UHTable *table, size_t buckets)
 }
 
 
+struct UHNode *uc_htable_iter_first_hash(struct UHTable *table,
+                                         struct UHIter *iter, size_t hash)
+{
+    size_t bucket = uc_htable_bucket(table, hash);
+    struct UHNode **it= &table->buckets[bucket];
+
+    while (*it) {
+        if ((*it)->hash == hash) {
+            iter->it = it;
+            iter->cur_bucket = bucket;
+            iter->cur_hash = (*it)->hash;
+            iter->next = &(*it)->next;
+            return *it;
+        }
+
+        it = &(*it)->next;
+    }
+
+    return NULL;
+}
+
+struct UHNode *uc_htable_iter_next_hash(struct UHIter *iter)
+{
+    struct UHNode **it = iter->next;
+
+    while (*it) {
+        if ((*it)->hash == iter->cur_hash) {
+            iter->it = it;
+            iter->next = &(*it)->next;
+            return *it;
+        }
+        it = &(*it)->next;
+    }
+
+    return NULL;
+}
+
+void uc_htable_iter_remove(struct UHIter *iter)
+{
+    if (*iter->it) {
+        *iter->it = *iter->next;
+        iter->it = NULL;
+    }
+}