libcamera: framebuffer: Replace vector with span in constructor

The FrameBuffer constructor takes a list of planes as an std::vector.
The caller may stores the planes in a different type of container,
resulting in the needless allocation of a temporary vector. Replace it
with a span.

Suggested-by: Daniel Rákos <daniel.rakos@rastergrid.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>

src/libcamera/pipeline/ipu3/ipu3.cpp

@@ -680,8 +680,12 @@ int PipelineHandlerIPU3::allocateBuffers(Camera *camera)
 
 	auto pushBuffers = [&](const std::vector<std::unique_ptr<FrameBuffer>> &buffers) {
 		for (const std::unique_ptr<FrameBuffer> &buffer : buffers) {
+			Span<const FrameBuffer::Plane> planes = buffer->planes();
+
 			buffer->setCookie(ipaBufferId++);
-			ipaBuffers_.emplace_back(buffer->cookie(), buffer->planes());
+			ipaBuffers_.emplace_back(buffer->cookie(),
+						 std::vector<FrameBuffer::Plane>{ planes.begin(),
+										  planes.end() });
 		}
 	};
 

src/libcamera/pipeline/mali-c55/mali-c55.cpp

@@ -1137,8 +1137,12 @@ int PipelineHandlerMaliC55::allocateBuffers(Camera *camera)
 			       std::queue<FrameBuffer *> &queue,
 			       std::vector<IPABuffer> &ipaBuffers) {
 		for (const std::unique_ptr<FrameBuffer> &buffer : buffers) {
+			Span<const FrameBuffer::Plane> planes = buffer->planes();
+
 			buffer->setCookie(ipaBufferId++);
-			ipaBuffers.emplace_back(buffer->cookie(), buffer->planes());
+			ipaBuffers.emplace_back(buffer->cookie(),
+						std::vector<FrameBuffer::Plane>{ planes.begin(),
+										 planes.end() });
 			queue.push(buffer.get());
 		}
 	};

src/libcamera/pipeline/rkisp1/rkisp1.cpp

@@ -1031,9 +1031,12 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
 	auto pushBuffers = [&](const std::vector<std::unique_ptr<FrameBuffer>> &buffers,
 			       std::queue<FrameBuffer *> &queue) {
 		for (const std::unique_ptr<FrameBuffer> &buffer : buffers) {
+			Span<const FrameBuffer::Plane> planes = buffer->planes();
+
 			buffer->setCookie(ipaBufferId++);
 			data->ipaBuffers_.emplace_back(buffer->cookie(),
-						       buffer->planes());
+						       std::vector<FrameBuffer::Plane>{ planes.begin(),
+											planes.end() });
 			queue.push(buffer.get());
 		}
 	};

src/libcamera/pipeline/rpi/common/pipeline_base.cpp

@@ -883,8 +883,10 @@ void PipelineHandlerBase::mapBuffers(Camera *camera, const BufferMap &buffers, u
 	 * handler and the IPA.
 	 */
 	for (auto const &[id, buffer] : buffers) {
-		bufferIds.push_back(IPABuffer(mask | id,
-					      buffer.buffer->planes()));
+		Span<const FrameBuffer::Plane> planes = buffer.buffer->planes();
+
+		bufferIds.emplace_back(mask | id,
+				       std::vector<FrameBuffer::Plane>{ planes.begin(), planes.end() });
 		data->bufferIds_.insert(mask | id);
 	}
 

src/libcamera/pipeline/vimc/vimc.cpp

@@ -363,8 +363,11 @@ int PipelineHandlerVimc::start(Camera *camera, [[maybe_unused]] const ControlLis
 	/* Map the mock IPA buffers to VIMC IPA to exercise IPC code paths. */
 	std::vector<IPABuffer> ipaBuffers;
 	for (auto [i, buffer] : utils::enumerate(data->mockIPABufs_)) {
+		Span<const FrameBuffer::Plane> planes = buffer->planes();
+
 		buffer->setCookie(i + 1);
-		ipaBuffers.emplace_back(buffer->cookie(), buffer->planes());
+		ipaBuffers.emplace_back(buffer->cookie(),
+					std::vector<FrameBuffer::Plane>{ planes.begin(), planes.end() });
 	}
 	data->ipa_->mapBuffers(ipaBuffers);
 

src/libcamera/pipeline/virtual/virtual.cpp

@@ -315,7 +315,8 @@ int PipelineHandlerVirtual::queueRequestDevice([[maybe_unused]] Camera *camera,
 				fmd.sequence = streamConfig.seq++;
 				fmd.timestamp = timestamp;
 
-				for (const auto [i, p] : utils::enumerate(buffer->planes()))
+				Span<const FrameBuffer::Plane> planes = buffer->planes();
+				for (const auto [i, p] : utils::enumerate(planes))
 					fmd.planes()[i].bytesused = p.length;
 
 				found = true;