From: Alan T. DeKok <aland@freeradius.org>
Date: Tue, 28 Sep 2021 19:26:45 +0000 (-0400)
Subject: add iteration functions
X-Git-Tag: release_3_0_24~5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=124f0a628c680ea518315a9273666858d4c5a5ae;p=thirdparty%2Ffreeradius-server.git

add iteration functions
---

diff --git a/src/include/hash.h b/src/include/hash.h
index 54259d70dd..71c8658995 100644
--- 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 d509388841..f9d088196f 100644
--- 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
 /*