libcamera: request: Make metadata_ a class instance

The metadata_ member variable is a pointer, for no specific reason.
Make it an instance and simplify the class constructor and destructor.

Suggested-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>

include/libcamera/internal/request.h

@@ -36,7 +36,7 @@ public:
 	Camera *camera() const { return camera_; }
 	bool hasPendingBuffers() const;
 
-	ControlList &metadata() { return *metadata_; }
+	ControlList &metadata() { return metadata_; }
 
 	bool completeBuffer(FrameBuffer *buffer);
 	void complete();
@@ -63,7 +63,7 @@ private:
 	std::unordered_set<FrameBuffer *> pending_;
 	std::map<FrameBuffer *, EventNotifier> notifiers_;
 	std::unique_ptr<Timer> timer_;
-	ControlList *metadata_;
+	ControlList metadata_;
 };
 
 } /* namespace libcamera */

src/libcamera/request.cpp

@@ -53,20 +53,17 @@ LOG_DEFINE_CATEGORY(Request)
 /**
  * \brief Create a Request::Private
  * \param camera The Camera that creates the request
+ *
+ * \todo Add a validator for metadata controls.
  */
 Request::Private::Private(Camera *camera)
-	: camera_(camera), cancelled_(false)
+	: camera_(camera), cancelled_(false), metadata_(controls::controls)
 {
-	/**
-	 * \todo Add a validator for metadata controls.
-	 */
-	metadata_ = new ControlList(controls::controls);
 }
 
 Request::Private::~Private()
 {
 	doCancelRequest();
-	delete metadata_;
 }
 
 /**
@@ -410,7 +407,7 @@ void Request::reuse(ReuseFlag flags)
 	status_ = RequestPending;
 
 	controls_->clear();
-	_d()->metadata_->clear();
+	_d()->metadata_.clear();
 }
 
 /**
@@ -435,7 +432,7 @@ void Request::reuse(ReuseFlag flags)
  */
 const ControlList &Request::metadata() const
 {
-	return *_d()->metadata_;
+	return _d()->metadata_;
 }
 
 /**