vppinfra: bihash walk cb typedef and continue/stop controls

Type: feature

Change-Id: I28f7a658be3f3beec9ea32635b60d1d3a10d9b06
Signed-off-by: Neale Ranns <nranns@cisco.com>

3 files changed, 24 insertions, 7 deletions

diff --git a/src/vppinfra/bihash_doc.h b/src/vppinfra/bihash_doc.h
index a7e70e9695c..da8c832f160 100644
--- a/src/vppinfra/bihash_doc.h
+++ b/src/vppinfra/bihash_doc.h
@@ -165,17 +165,25 @@ void clib_bihash_prefetch_data (clib_bihash * h, u64 hash);
 int clib_bihash_search_inline_2
   (clib_bihash * h, clib_bihash_kv * search_key, clib_bihash_kv * valuep);
 
+/* Calback function for walking a bihash table
+ *
+ * @param kv - KV pair visited
+ * @param ctx - Context passed to the walk
+ * @return BIHASH_WALK_CONTINUE to continue BIHASH_WALK_STOP to stop
+ */
+typedef int (*clib_bihash_foreach_key_value_pair_cb) (clib_bihash_kv * kv,
+						      void *ctx);
+
 /** Visit active (key,value) pairs in a bi-hash table
 
     @param h - the bi-hash table to search
     @param callback - function to call with each active (key,value) pair
     @param arg - arbitrary second argument passed to the callback function
     First argument is the (key,value) pair to visit
-    @note Trying to supply a proper function prototype for the
-    callback function appears to be a fool's errand.
 */
 void clib_bihash_foreach_key_value_pair (clib_bihash * h,
-					 void *callback, void *arg);
+					 clib_bihash_foreach_key_value_pair_cb
+					 * callback, void *arg);
 
 /*
  * fd.io coding-style-patch-verification: ON
diff --git a/src/vppinfra/bihash_template.c b/src/vppinfra/bihash_template.c
index 97c4cd08eb1..b090041ad29 100644
--- a/src/vppinfra/bihash_template.c
+++ b/src/vppinfra/bihash_template.c
@@ -906,12 +906,12 @@ u8 *BV (format_bihash) (u8 * s, va_list * args)
 }
 
 void BV (clib_bihash_foreach_key_value_pair)
-  (BVT (clib_bihash) * h, void *callback, void *arg)
+  (BVT (clib_bihash) * h,
+   BV (clib_bihash_foreach_key_value_pair_cb) cb, void *arg)
 {
   int i, j, k;
   BVT (clib_bihash_bucket) * b;
   BVT (clib_bihash_value) * v;
-  void (*fp) (BVT (clib_bihash_kv) *, void *) = callback;
 
   if (PREDICT_FALSE (alloc_arena (h) == 0))
     return;
@@ -930,7 +930,8 @@ void BV (clib_bihash_foreach_key_value_pair)
 	      if (BV (clib_bihash_is_free) (&v->kvp[k]))
 		continue;
 
-	      (*fp) (&v->kvp[k], arg);
+	      if (BIHASH_WALK_STOP == cb (&v->kvp[k], arg))
+		return;
 	      /*
 	       * In case the callback deletes the last entry in the bucket...
 	       */
diff --git a/src/vppinfra/bihash_template.h b/src/vppinfra/bihash_template.h
index ebd70c03371..f11e6d506ab 100644
--- a/src/vppinfra/bihash_template.h
+++ b/src/vppinfra/bihash_template.h
@@ -328,8 +328,16 @@ int BV (clib_bihash_search) (BVT (clib_bihash) * h,
 			     BVT (clib_bihash_kv) * search_v,
 			     BVT (clib_bihash_kv) * return_v);
 
+#define BIHASH_WALK_STOP 0
+#define BIHASH_WALK_CONTINUE 1
+
+typedef
+  int (*BV (clib_bihash_foreach_key_value_pair_cb)) (BVT (clib_bihash_kv) *,
+						     void *);
 void BV (clib_bihash_foreach_key_value_pair) (BVT (clib_bihash) * h,
-					      void *callback, void *arg);
+					      BV
+					      (clib_bihash_foreach_key_value_pair_cb)
+					      cb, void *arg);
 void *clib_all_bihash_set_heap (void);
 void clib_bihash_copied (void *dst, void *src);