[ovs-dev] [PATCH] sset: Add sset_at_position() function.

Justin Pettit jpettit at nicira.com
Thu Nov 1 06:15:18 UTC 2012


This will be useful in a future commit.

Suggested-by: Ben Pfaff <blp at nicira.com>
Signed-off-by: Justin Pettit <jpettit at nicira.com>
---
 lib/sset.c |   19 +++++++++++++++++++
 lib/sset.h |    2 ++
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/lib/sset.c b/lib/sset.c
index ee4224a..04039a7 100644
--- a/lib/sset.c
+++ b/lib/sset.c
@@ -251,3 +251,22 @@ sset_equals(const struct sset *a, const struct sset *b)
 
     return true;
 }
+
+/* Returns the next node in 'set' in hash order, or NULL if no nodes remain in
+ * 'set'.  Uses '*bucketp' and '*offsetp' to determine where to begin
+ * iteration, and stores new values to pass on the next iteration into them
+ * before returning.
+ *
+ * It's better to use plain SSET_FOR_EACH and related functions, since they are
+ * faster and better at dealing with ssets that change during iteration.
+ *
+ * Before beginning iteration, store 0 into '*bucketp' and '*offsetp'.
+ */
+struct sset_node *
+sset_at_position(const struct sset *set, uint32_t *bucketp, uint32_t *offsetp)
+{
+    struct hmap_node *hmap_node;
+
+    hmap_node = hmap_at_position(&set->map, bucketp, offsetp);
+    return SSET_NODE_FROM_HMAP_NODE(hmap_node);
+}
diff --git a/lib/sset.h b/lib/sset.h
index f63f4ab..327074c 100644
--- a/lib/sset.h
+++ b/lib/sset.h
@@ -64,6 +64,8 @@ char *sset_pop(struct sset *);
 struct sset_node *sset_find(const struct sset *, const char *);
 bool sset_contains(const struct sset *, const char *);
 bool sset_equals(const struct sset *, const struct sset *);
+struct sset_node *sset_at_position(const struct sset *,
+                                   uint32_t *bucketp, uint32_t *offsetp);
 
 /* Iteration macros. */
 #define SSET_FOR_EACH(NAME, SSET)               \
-- 
1.7.5.4




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