add iteration functions

diff --git a/src/include/hash.h b/src/include/hash.h
index 54259d70dd27dbdf896bf74f6a418938bf05999f..71c8658995bfc620cf4af173222cebd4bde6775f 100644 (file)
--- a/src/include/hash.h
+++ b/src/include/hash.h
@@ -58,6 +58,16 @@ int          fr_hash_table_walk(fr_hash_table_t *ht,
                                     fr_hash_table_walk_t callback,
                                     void *ctx);
 
+typedef struct fr_hash_entry_s fr_hash_entry_t;
+
+typedef struct fr_hash_iter_s {
+       uint32_t                bucket;
+       fr_hash_entry_t         *node;
+} fr_hash_iter_t;
+
+void           *fr_hash_table_iter_init(fr_hash_table_t *ht, fr_hash_iter_t *iter);
+void           *fr_hash_table_iter_next(fr_hash_table_t *ht, fr_hash_iter_t *iter);
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/src/lib/hash.c b/src/lib/hash.c
index d509388841e9194c5228d4bcb0a420d6d009efa9..f9d088196f294b1cf1df4a64bdc7d8715bc69220 100644 (file)
--- a/src/lib/hash.c
+++ b/src/lib/hash.c
@@ -40,12 +40,12 @@ RCSID("$Id$")
  */
 #define FR_HASH_NUM_BUCKETS (64)
 
-typedef struct fr_hash_entry_t {
-       struct fr_hash_entry_t *next;
+struct fr_hash_entry_s {
+       fr_hash_entry_t *next;
        uint32_t        reversed;
        uint32_t        key;
        void const      *data;
-} fr_hash_entry_t;
+};
 
 
 struct fr_hash_table_t {
@@ -620,6 +620,81 @@ int fr_hash_table_walk(fr_hash_table_t *ht,
        return 0;
 }
 
+/** Iterate over entries in a hash table
+ *
+ * @note If the hash table is modified the iterator should be considered invalidated.
+ *
+ * @param[in] ht       to iterate over.
+ * @param[in] iter     Pointer to an iterator struct, used to maintain
+ *                     state between calls.
+ * @return
+ *     - User data.
+ *     - NULL if at the end of the list.
+ */
+void *fr_hash_table_iter_next(fr_hash_table_t *ht, fr_hash_iter_t *iter)
+{
+       fr_hash_entry_t *node;
+       uint32_t        i;
+       void            *out;
+
+       /*
+        *      Return the next element in the bucket
+        */
+       if (iter->node != &ht->null) {
+               node = iter->node;
+               iter->node = node->next;
+
+               memcpy(&out, &node->data, sizeof(out)); /* const issues */
+               return out;
+       }
+
+       if (iter->bucket == 0) return NULL;
+
+       /*
+        *      We might have to go through multiple empty
+        *      buckets to find one that contains something
+        *      we should return
+        */
+       i = iter->bucket - 1;
+       for (;;) {
+               if (!ht->buckets[i]) fr_hash_table_fixup(ht, i);
+
+               node = ht->buckets[i];
+               if (node == &ht->null) {
+                       if (i == 0) break;
+                       i--;
+                       continue;       /* This bucket was empty too... */
+               }
+
+               iter->node = node->next;                /* Store the next one to examine */
+               iter->bucket = i;
+
+               memcpy(&out, &node->data, sizeof(out)); /* const issues */
+               return out;
+       }
+       iter->bucket = i;
+
+       return NULL;
+}
+
+/** Initialise an iterator
+ *
+ * @note If the hash table is modified the iterator should be considered invalidated.
+ *
+ * @param[in] ht       to iterate over.
+ * @param[out] iter    to initialise.
+ * @return
+ *     - The first entry in the hash table.
+ *     - NULL if the hash table is empty.
+ */
+void *fr_hash_table_iter_init(fr_hash_table_t *ht, fr_hash_iter_t *iter)
+{
+       iter->bucket = ht->num_buckets;
+       iter->node = &ht->null;
+
+       return fr_hash_table_iter_next(ht, iter);
+}
+
 
 #ifdef TESTING
 /*