[libcamera-devel] [PATCH v3 3/3] libcamera: V4L2Device: Use Span in updateControls()

[Kieran Bingham]

Hi Hiro,

On 21/04/2021 11:16, Laurent Pinchart wrote:
> Hi Hiro,
> 
> Thank you for the patch.
> 
> On Wed, Apr 21, 2021 at 06:38:57PM +0900, Hirokazu Honda wrote:
>> V4L2Device::updateControls() takes two arguments, raw array and
>> its size, for the v4l2_ext_control values. This replaces it with
>> libcamera::Span.
>>
>> Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
>> ---
>>  include/libcamera/internal/v4l2_device.h |  4 ++--
>>  src/libcamera/v4l2_device.cpp            | 13 ++++++-------
>>  2 files changed, 8 insertions(+), 9 deletions(-)
>>
>> diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h
>> index d006bf68..7c79ee97 100644
>> --- a/include/libcamera/internal/v4l2_device.h
>> +++ b/include/libcamera/internal/v4l2_device.h
>> @@ -14,6 +14,7 @@
>>  #include <linux/videodev2.h>
>>  
>>  #include <libcamera/signal.h>
>> +#include <libcamera/span.h>
>>  
>>  #include "libcamera/internal/log.h"
>>  #include "libcamera/internal/v4l2_controls.h"
>> @@ -55,8 +56,7 @@ protected:
>>  private:
>>  	void listControls();
>>  	void updateControls(ControlList *ctrls,
>> -			    const struct v4l2_ext_control *v4l2Ctrls,
>> -			    unsigned int count);
>> +			    libcamera::Span<const v4l2_ext_control> v4l2Ctrls);

Given that we are in the libcamera namespace here, is the libcamera::
prefix required?


>>  
>>  	void eventAvailable(EventNotifier *notifier);
>>  
>> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
>> index 109269b2..a59e8378 100644
>> --- a/src/libcamera/v4l2_device.cpp
>> +++ b/src/libcamera/v4l2_device.cpp
>> @@ -250,7 +250,8 @@ ControlList V4L2Device::getControls(const std::vector<uint32_t> &ids)
>>  		v4l2Ctrls.resize(errorIdx);
>>  	}
>>  
>> -	updateControls(&ctrls, v4l2Ctrls.data(), v4l2Ctrls.size());
>> +	updateControls(&ctrls,
>> +		       libcamera::Span<const v4l2_ext_control>(v4l2Ctrls));
> 
> The Span constructor that takes a container is implicit, so I think you
> can write
> 
> 	updateControls(&ctrls, v4l2Ctrls);
> 
>>  
>>  	return ctrls;
>>  }
>> @@ -349,7 +350,8 @@ int V4L2Device::setControls(ControlList *ctrls)
>>  		ret = errorIdx;
>>  	}
>>  
>> -	updateControls(ctrls, v4l2Ctrls.data(), v4l2Ctrls.size());
>> +	updateControls(ctrls,
>> +		       libcamera::Span<const v4l2_ext_control>(v4l2Ctrls));
> 
> Same here.
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> 
>>  
>>  	return ret;
>>  }
>> @@ -513,14 +515,11 @@ void V4L2Device::listControls()
>>   * values in \a v4l2Ctrls
>>   * \param[inout] ctrls List of V4L2 controls to update
>>   * \param[in] v4l2Ctrls List of V4L2 extended controls as returned by the driver
>> - * \param[in] count The number of controls to update
>>   */
>>  void V4L2Device::updateControls(ControlList *ctrls,
>> -				const struct v4l2_ext_control *v4l2Ctrls,
>> -				unsigned int count)
>> +				libcamera::Span<const v4l2_ext_control> v4l2Ctrls)
>>  {
>> -	for (unsigned int i = 0; i < count; i++) {
>> -		const struct v4l2_ext_control &v4l2Ctrl = v4l2Ctrls[i];
>> +	for (const v4l2_ext_control &v4l2Ctrl : v4l2Ctrls) {


That's nicer indeed.

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

>>  		const unsigned int id = v4l2Ctrl.id;
>>  		if (!ctrls->contains(id)) {
>>  			LOG(V4L2, Error) << "ControlList doesn't contain id: "
> 

-- 
Regards
--
Kieran