[libcamera-devel] [PATCH v2 2/3] libcamera: use const reference for range loops

[Laurent Pinchart]

Hi Christian,

Thank you for the patch.

On Tue, Aug 16, 2022 at 08:38:25PM +0200, Christian Rauch via libcamera-devel wrote:
> A const reference prevents unnecessary copies of the loop elements.

This should also mention that PipelineHandlerUVC::processControls()
switches to structured bindings. With that,

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

You can propose an updated commit message in a reply to this e-mail,
there's no need to resubmit the series.

> Signed-off-by: Christian Rauch <Rauch.Christian at gmx.de>
> ---
>  src/libcamera/camera_manager.cpp             | 2 +-
>  src/libcamera/device_enumerator.cpp          | 2 +-
>  src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 6 +-----
>  src/libcamera/pipeline/vimc/vimc.cpp         | 2 +-
>  src/libcamera/pipeline_handler.cpp           | 2 +-
>  5 files changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> index 70d73822..7ff4bc6f 100644
> --- a/src/libcamera/camera_manager.cpp
> +++ b/src/libcamera/camera_manager.cpp
> @@ -189,7 +189,7 @@ void CameraManager::Private::addCamera(std::shared_ptr<Camera> camera,
>  {
>  	MutexLocker locker(mutex_);
> 
> -	for (std::shared_ptr<Camera> c : cameras_) {
> +	for (const std::shared_ptr<Camera> &c : cameras_) {
>  		if (c->id() == camera->id()) {
>  			LOG(Camera, Fatal)
>  				<< "Trying to register a camera with a duplicated ID '"
> diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
> index d1258050..f2e055de 100644
> --- a/src/libcamera/device_enumerator.cpp
> +++ b/src/libcamera/device_enumerator.cpp
> @@ -161,7 +161,7 @@ std::unique_ptr<DeviceEnumerator> DeviceEnumerator::create()
> 
>  DeviceEnumerator::~DeviceEnumerator()
>  {
> -	for (std::shared_ptr<MediaDevice> media : devices_) {
> +	for (const std::shared_ptr<MediaDevice> &media : devices_) {
>  		if (media->busy())
>  			LOG(DeviceEnumerator, Error)
>  				<< "Removing media device " << media->deviceNode()
> diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> index fbe02cdc..9cbf126a 100644
> --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
> @@ -340,12 +340,8 @@ int PipelineHandlerUVC::processControls(UVCCameraData *data, Request *request)
>  {
>  	ControlList controls(data->video_->controls());
> 
> -	for (auto it : request->controls()) {
> -		unsigned int id = it.first;
> -		ControlValue &value = it.second;
> -
> +	for (const auto &[id, value] : request->controls())
>  		processControl(&controls, id, value);
> -	}
> 
>  	for (const auto &ctrl : controls)
>  		LOG(UVC, Debug)
> diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp
> index 153cf849..d2f2e460 100644
> --- a/src/libcamera/pipeline/vimc/vimc.cpp
> +++ b/src/libcamera/pipeline/vimc/vimc.cpp
> @@ -378,7 +378,7 @@ int PipelineHandlerVimc::processControls(VimcCameraData *data, Request *request)
>  {
>  	ControlList controls(data->sensor_->controls());
> 
> -	for (auto it : request->controls()) {
> +	for (const auto &it : request->controls()) {
>  		unsigned int id = it.first;
>  		unsigned int offset;
>  		uint32_t cid;
> diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
> index 7d2d00ef..e5cb751c 100644
> --- a/src/libcamera/pipeline_handler.cpp
> +++ b/src/libcamera/pipeline_handler.cpp
> @@ -616,7 +616,7 @@ void PipelineHandler::disconnect()
>  	 */
>  	std::vector<std::weak_ptr<Camera>> cameras{ std::move(cameras_) };
> 
> -	for (std::weak_ptr<Camera> ptr : cameras) {
> +	for (const std::weak_ptr<Camera> &ptr : cameras) {
>  		std::shared_ptr<Camera> camera = ptr.lock();
>  		if (!camera)
>  			continue;

-- 
Regards,

Laurent Pinchart