GHash: Add BLI_ghash_ensure_p_ex to copy the key

Needed in cases where the memory from each key is owned by the GHash.

2 files changed, 25 insertions, 2 deletions

diff --git a/source/blender/blenlib/BLI_ghash.h b/source/blender/blenlib/BLI_ghash.h
index a5c397f32f0..f5cc6c6b90c 100644
--- a/source/blender/blenlib/BLI_ghash.h
+++ b/source/blender/blenlib/BLI_ghash.h
@@ -44,8 +44,8 @@ typedef unsigned int  (*GHashHashFP)     (const void *key);
 typedef bool          (*GHashCmpFP)      (const void *a, const void *b);
 typedef void          (*GHashKeyFreeFP)  (void *key);
 typedef void          (*GHashValFreeFP)  (void *val);
-typedef void         *(*GHashKeyCopyFP)  (void *key);
-typedef void         *(*GHashValCopyFP)  (void *val);
+typedef void         *(*GHashKeyCopyFP)  (const void *key);
+typedef void         *(*GHashValCopyFP)  (const void *val);
 
 typedef struct GHash GHash;
 
@@ -80,6 +80,7 @@ void  *BLI_ghash_lookup(GHash *gh, const void *key) ATTR_WARN_UNUSED_RESULT;
 void  *BLI_ghash_lookup_default(GHash *gh, const void *key, void *val_default) ATTR_WARN_UNUSED_RESULT;
 void **BLI_ghash_lookup_p(GHash *gh, const void *key) ATTR_WARN_UNUSED_RESULT;
 bool   BLI_ghash_ensure_p(GHash *gh, void *key, void ***r_val) ATTR_WARN_UNUSED_RESULT;
+bool   BLI_ghash_ensure_p_ex(GHash *gh, const void *key, void ***r_val, GHashKeyCopyFP keycopyfp) ATTR_WARN_UNUSED_RESULT;
 bool   BLI_ghash_remove(GHash *gh, void *key, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp);
 void   BLI_ghash_clear(GHash *gh, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp);
 void   BLI_ghash_clear_ex(GHash *gh, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp,
diff --git a/source/blender/blenlib/intern/BLI_ghash.c b/source/blender/blenlib/intern/BLI_ghash.c
index 950d164bdbe..b0902fe727f 100644
--- a/source/blender/blenlib/intern/BLI_ghash.c
+++ b/source/blender/blenlib/intern/BLI_ghash.c
@@ -767,6 +767,28 @@ bool BLI_ghash_ensure_p(GHash *gh, void *key, void ***r_val)
 }
 
 /**
+ * A version of #BLI_ghash_ensure_p copies the key on insertion.
+ */
+bool BLI_ghash_ensure_p_ex(
+        GHash *gh, const void *key, void ***r_val,
+        GHashKeyCopyFP keycopyfp)
+{
+	const unsigned int hash = ghash_keyhash(gh, key);
+	const unsigned int bucket_index = ghash_bucket_index(gh, hash);
+	GHashEntry *e = (GHashEntry *)ghash_lookup_entry_ex(gh, key, bucket_index);
+	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);
+	}
+
+	*r_val = &e->val;
+	return haskey;
+}
+
+/**
  * Remove \a key from \a gh, or return false if the key wasn't found.
  *
  * \param key  The key to remove.