Cleanup: add resource manager for cryptomatte session.

Auto frees cryptomatte session when it the pointer is collected from the
stack.

Reviewed By: Jacques Lucke

Differential Revision: https://developer.blender.org/D10667

source/blender/blenkernel/BKE_cryptomatte.hh

@@ -29,6 +29,8 @@
 #include "BLI_map.hh"
 #include "BLI_string_ref.hh"
 
+#include "BKE_cryptomatte.h"
+
 struct ID;
 
 namespace blender::bke::cryptomatte {
@@ -103,4 +105,13 @@ struct CryptomatteStampDataCallbackData {
   static void extract_layer_manifest(void *_data, const char *propname, char *propvalue, int len);
 };
 
+struct CryptomatteSessionDeleter {
+  void operator()(CryptomatteSession *session)
+  {
+    BKE_cryptomatte_free(session);
+  }
+};
+
+using CryptomatteSessionPtr = std::unique_ptr<CryptomatteSession, CryptomatteSessionDeleter>;
+
 }  // namespace blender::bke::cryptomatte

source/blender/blenkernel/intern/cryptomatte_test.cc

@@ -157,8 +157,8 @@ TEST(cryptomatte, session_from_stamp_data)
   BKE_render_result_stamp_data(render_result, "cryptomatte/uiop/name", "layer2");
   BKE_render_result_stamp_data(
       render_result, "cryptomatte/uiop/manifest", "{\"Object2\":\"87654321\"}");
-  CryptomatteSession *session = BKE_cryptomatte_init_from_render_result(render_result);
-  EXPECT_NE(session, nullptr);
+  CryptomatteSessionPtr session(BKE_cryptomatte_init_from_render_result(render_result));
+  EXPECT_NE(session.get(), nullptr);
   RE_FreeRenderResult(render_result);
 
   /* Create StampData from CryptomatteSession. */
@@ -166,14 +166,13 @@ TEST(cryptomatte, session_from_stamp_data)
   BLI_strncpy(view_layer.name, "viewlayername", sizeof(view_layer.name));
   RenderResult *render_result2 = static_cast<RenderResult *>(
       MEM_callocN(sizeof(RenderResult), __func__));
-  BKE_cryptomatte_store_metadata(session, render_result2, &view_layer);
+  BKE_cryptomatte_store_metadata(session.get(), render_result2, &view_layer);
 
   /* Validate StampData. */
   BKE_stamp_info_callback(
       nullptr, render_result2->stamp_data, validate_cryptomatte_session_from_stamp_data, false);
 
   RE_FreeRenderResult(render_result2);
-  BKE_cryptomatte_free(session);
 }
 
 }  // namespace blender::bke::cryptomatte::tests