Smallhash: add support for iterating value pointers

also add reinsert function

2 files changed, 48 insertions, 2 deletions

diff --git a/source/blender/blenlib/BLI_smallhash.h b/source/blender/blenlib/BLI_smallhash.h
index b80044bccff..5bc40a60515 100644
--- a/source/blender/blenlib/BLI_smallhash.h
+++ b/source/blender/blenlib/BLI_smallhash.h
@@ -61,13 +61,16 @@ void    BLI_smallhash_init_ex(SmallHash *sh,
 void    BLI_smallhash_init(SmallHash *sh) ATTR_NONNULL(1);
 void    BLI_smallhash_release(SmallHash *sh) ATTR_NONNULL(1);
 void    BLI_smallhash_insert(SmallHash *sh, uintptr_t key, void *item) ATTR_NONNULL(1);
+bool    BLI_smallhash_reinsert(SmallHash *sh, uintptr_t key, void *item) ATTR_NONNULL(1);
 bool    BLI_smallhash_remove(SmallHash *sh, uintptr_t key) ATTR_NONNULL(1);
 void   *BLI_smallhash_lookup(SmallHash *sh, uintptr_t key) ATTR_NONNULL(1) ATTR_WARN_UNUSED_RESULT;
 void  **BLI_smallhash_lookup_p(SmallHash *sh, uintptr_t key) ATTR_NONNULL(1) ATTR_WARN_UNUSED_RESULT;
 bool    BLI_smallhash_haskey(SmallHash *sh, uintptr_t key) ATTR_NONNULL(1);
 int     BLI_smallhash_count(SmallHash *sh)  ATTR_NONNULL(1);
 void   *BLI_smallhash_iternext(SmallHashIter *iter, uintptr_t *key)  ATTR_NONNULL(1) ATTR_WARN_UNUSED_RESULT;
+void  **BLI_smallhash_iternext_p(SmallHashIter *iter, uintptr_t *key)  ATTR_NONNULL(1) ATTR_WARN_UNUSED_RESULT;
 void   *BLI_smallhash_iternew(SmallHash *sh, SmallHashIter *iter, uintptr_t *key) ATTR_NONNULL(1) ATTR_WARN_UNUSED_RESULT;
+void  **BLI_smallhash_iternew_p(SmallHash *sh, SmallHashIter *iter, uintptr_t *key) ATTR_NONNULL(1) ATTR_WARN_UNUSED_RESULT;
 /* void BLI_smallhash_print(SmallHash *sh); */ /* UNUSED */
 
 #ifdef DEBUG
diff --git a/source/blender/blenlib/intern/smallhash.c b/source/blender/blenlib/intern/smallhash.c
index 0cf9f69b9ae..bb91f48d396 100644
--- a/source/blender/blenlib/intern/smallhash.c
+++ b/source/blender/blenlib/intern/smallhash.c
@@ -246,6 +246,26 @@ void BLI_smallhash_insert(SmallHash *sh, uintptr_t key, void *val)
 	e->val = val;
 }
 
+/**
+ * Inserts a new value to a key that may already be in ghash.
+ *
+ * Avoids #BLI_smallhash_remove, #BLI_smallhash_insert calls (double lookups)
+ *
+ * \returns true if a new key has been added.
+ */
+bool BLI_smallhash_reinsert(SmallHash *sh, uintptr_t key, void *item)
+{
+	SmallHashEntry *e = smallhash_lookup(sh, key);
+	if (e) {
+		e->val = item;
+		return false;
+	}
+	else {
+		BLI_smallhash_insert(sh, key, item);
+		return true;
+	}
+}
+
 #ifdef USE_REMOVE
 bool BLI_smallhash_remove(SmallHash *sh, uintptr_t key)
 {
@@ -290,7 +310,7 @@ int BLI_smallhash_count(SmallHash *sh)
 	return (int)sh->nentries;
 }
 
-void *BLI_smallhash_iternext(SmallHashIter *iter, uintptr_t *key)
+BLI_INLINE SmallHashEntry *smallhash_iternext(SmallHashIter *iter, uintptr_t *key)
 {
 	while (iter->i < iter->sh->nbuckets) {
 		if (smallhash_val_is_used(iter->sh->buckets[iter->i].val)) {
@@ -298,7 +318,7 @@ void *BLI_smallhash_iternext(SmallHashIter *iter, uintptr_t *key)
 				*key = iter->sh->buckets[iter->i].key;
 			}
 
-			return iter->sh->buckets[iter->i++].val;
+			return &iter->sh->buckets[iter->i++];
 		}
 
 		iter->i++;
@@ -307,6 +327,20 @@ void *BLI_smallhash_iternext(SmallHashIter *iter, uintptr_t *key)
 	return NULL;
 }
 
+void *BLI_smallhash_iternext(SmallHashIter *iter, uintptr_t *key)
+{
+	SmallHashEntry *e = smallhash_iternext(iter, key);
+
+	return e ? e->val : NULL;
+}
+
+void **BLI_smallhash_iternext_p(SmallHashIter *iter, uintptr_t *key)
+{
+	SmallHashEntry *e = smallhash_iternext(iter, key);
+
+	return e ? &e->val : NULL;
+}
+
 void *BLI_smallhash_iternew(SmallHash *sh, SmallHashIter *iter, uintptr_t *key)
 {
 	iter->sh = sh;
@@ -315,6 +349,15 @@ void *BLI_smallhash_iternew(SmallHash *sh, SmallHashIter *iter, uintptr_t *key)
 	return BLI_smallhash_iternext(iter, key);
 }
 
+void **BLI_smallhash_iternew_p(SmallHash *sh, SmallHashIter *iter, uintptr_t *key)
+{
+	iter->sh = sh;
+	iter->i = 0;
+
+	return BLI_smallhash_iternext_p(iter, key);
+}
+
+
 /** \name Debugging & Introspection
  * \{ */