GHash: BLI_ghash_ensure_p_ex now takes a pointer-to-key arg

This is an alternative to passing a copy callback which is some times inconvenient.
Instead the caller can write to the key - needed when the key is duplicated memory.

Allows for minor optimization in ghash/gset use.

Also add BLI_gset_ensure_p_ex

1 files changed, 29 insertions, 5 deletions

diff --git a/source/blender/blenlib/intern/BLI_ghash.c b/source/blender/blenlib/intern/BLI_ghash.c
index 21b0a5860af..0cb30208642 100644
--- a/source/blender/blenlib/intern/BLI_ghash.c
+++ b/source/blender/blenlib/intern/BLI_ghash.c
@@ -836,11 +836,13 @@ bool BLI_ghash_ensure_p(GHash *gh, void *key, void ***r_val)
 }
 
 /**
- * A version of #BLI_ghash_ensure_p copies the key on insertion.
+ * A version of #BLI_ghash_ensure_p that allows caller to re-assign the key.
+ * Typically used when the key is to be duplicated.
+ *
+ * \warning Caller _must_ write to \a r_key when returning false.
  */
 bool BLI_ghash_ensure_p_ex(
-        GHash *gh, const void *key, void ***r_val,
-        GHashKeyCopyFP keycopyfp)
+        GHash *gh, const void *key, void ***r_key, void ***r_val)
 {
 	const unsigned int hash = ghash_keyhash(gh, key);
 	const unsigned int bucket_index = ghash_bucket_index(gh, hash);
@@ -848,11 +850,11 @@ bool BLI_ghash_ensure_p_ex(
 	const bool haskey = (e != NULL);
 
 	if (!haskey) {
-		/* keycopyfp(key) is the only difference to BLI_ghash_ensure_p */
 		e = BLI_mempool_alloc(gh->entrypool);
-		ghash_insert_ex_keyonly_entry(gh, keycopyfp(key), bucket_index, (Entry *)e);
+		ghash_insert_ex_keyonly_entry(gh, NULL, bucket_index, (Entry *)e);
 	}
 
+	*r_key = &e->e.key;
 	*r_val = &e->val;
 	return haskey;
 }
@@ -1391,6 +1393,28 @@ bool BLI_gset_add(GSet *gs, void *key)
 }
 
 /**
+ * Set counterpart to #BLI_ghash_ensure_p_ex.
+ * similar to BLI_gset_add, except it returns the key pointer.
+ *
+ * \warning Caller _must_ write to \a r_key when returning false.
+ */
+bool BLI_gset_ensure_p_ex(GSet *gs, const void *key, void ***r_key)
+{
+	const unsigned int hash = ghash_keyhash((GHash *)gs, key);
+	const unsigned int bucket_index = ghash_bucket_index((GHash *)gs, hash);
+	GSetEntry *e = (GSetEntry *)ghash_lookup_entry_ex((GHash *)gs, key, bucket_index);
+	const bool haskey = (e != NULL);
+
+	if (!haskey) {
+		e = BLI_mempool_alloc(((GHash *)gs)->entrypool);
+		ghash_insert_ex_keyonly_entry((GHash *)gs, NULL, bucket_index, (Entry *)e);
+	}
+
+	*r_key = &e->key;
+	return haskey;
+}
+
+/**
  * Adds the key to the set (duplicates are managed).
  * Matching #BLI_ghash_reinsert
  *