1 files changed, 57 insertions, 3 deletions

diff --git a/source/blender/blenlib/intern/BLI_ghash.c b/source/blender/blenlib/intern/BLI_ghash.c
index b30553d0b5e..74d7fdc88cb 100644
--- a/source/blender/blenlib/intern/BLI_ghash.c
+++ b/source/blender/blenlib/intern/BLI_ghash.c
@@ -399,7 +399,7 @@ void *BLI_ghash_lookup_default(GHash *gh, const void *key, void *val_default)
  * \param key  The key to lookup.
  * \returns the pointer to value for \a key or NULL.
  *
- * \note This has 2 main benifits over #BLI_ghash_lookup.
+ * \note This has 2 main benefits over #BLI_ghash_lookup.
  * - A NULL return always means that \a key isn't in \a gh.
  * - The value can be modified in-place without further function calls (faster).
  */
@@ -570,12 +570,12 @@ void BLI_ghashIterator_init(GHashIterator *ghi, GHash *gh)
 	ghi->curEntry = NULL;
 	ghi->curBucket = UINT_MAX;  /* wraps to zero */
 	if (gh->nentries) {
-		while (!ghi->curEntry) {
+		do {
 			ghi->curBucket++;
 			if (UNLIKELY(ghi->curBucket == ghi->gh->nbuckets))
 				break;
 			ghi->curEntry = ghi->gh->buckets[ghi->curBucket];
-		}
+		} while (!ghi->curEntry);
 	}
 }
 
@@ -704,6 +704,11 @@ unsigned int BLI_ghashutil_uinthash_v4(const unsigned int key[4])
 	return hash;
 }
 
+int BLI_ghashutil_uinthash_v4_cmp(const void *a, const void *b)
+{
+	return memcmp(a, b, sizeof(unsigned int[4]));
+}
+
 unsigned int BLI_ghashutil_uinthash(unsigned int key)
 {
 	key += ~(key << 16);
@@ -967,6 +972,17 @@ void BLI_gset_free(GSet *gs, GSetKeyFreeFP keyfreefp)
 {
 	BLI_ghash_free((GHash *)gs, keyfreefp, NULL);
 }
+
+void BLI_gset_flag_set(GSet *gs, unsigned int flag)
+{
+	((GHash *)gs)->flag |= flag;
+}
+
+void BLI_gset_flag_clear(GSet *gs, unsigned int flag)
+{
+	((GHash *)gs)->flag &= ~flag;
+}
+
 /** \} */
 
 
@@ -996,3 +1012,41 @@ GSet *BLI_gset_pair_new(const char *info)
 }
 
 /** \} */
+
+
+/** \name Debugging & Introspection
+ * \{ */
+#ifdef DEBUG
+
+/**
+ * Measure how well the hash function performs
+ * (1.0 is approx as good as random distribution).
+ *
+ * Smaller is better!
+ */
+double BLI_ghash_calc_quality(GHash *gh)
+{
+	uint64_t sum = 0;
+	unsigned int i;
+
+	if (gh->nentries == 0)
+		return -1.0;
+
+	for (i = 0; i < gh->nbuckets; i++) {
+		uint64_t count = 0;
+		Entry *e;
+		for (e = gh->buckets[i]; e; e = e->next) {
+			count += 1;
+		}
+		sum += count * (count + 1);
+	}
+	return ((double)sum * (double)gh->nbuckets /
+	        ((double)gh->nentries * (gh->nentries + 2 * gh->nbuckets - 1)));
+}
+double BLI_gset_calc_quality(GSet *gs)
+{
+	return BLI_ghash_calc_quality((GHash *)gs);
+}
+
+#endif
+/** \} */