[libcamera-devel] [RFC 03/12] libcamera: pipeline: Add helper to find request from buffer

[Niklas Söderlund]

Hi Laurent,

Thanks for your feedback.

On 2019-11-18 21:14:42 +0200, Laurent Pinchart wrote:
> Hi Niklas,
> 
> Thank you for the patch.
> 
> On Mon, Oct 28, 2019 at 03:25:16AM +0100, Niklas Söderlund wrote:
> > The pipeline knows which buffer coming from the application belongs to
> > which request. Add a helper to allow pipeline implementations to access
> > this knowledge.
> > 
> > Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> 
> Why is this needed, given that Buffer stores a pointer to Request ? I
> assume I'll find out later in the series, but it seems more efficient to
> rely on the pointer.

This is needed as the Buffer will no longer keep a reference to a 
Request.

> 
> > ---
> >  src/libcamera/include/pipeline_handler.h |  2 ++
> >  src/libcamera/pipeline_handler.cpp       | 10 ++++++++++
> >  2 files changed, 12 insertions(+)
> > 
> > diff --git a/src/libcamera/include/pipeline_handler.h b/src/libcamera/include/pipeline_handler.h
> > index 320740746bc6e998..6024357e266c2e2b 100644
> > --- a/src/libcamera/include/pipeline_handler.h
> > +++ b/src/libcamera/include/pipeline_handler.h
> > @@ -39,6 +39,8 @@ public:
> >  	}
> >  	virtual ~CameraData() {}
> >  
> > +	Request *requestFromBuffer(Buffer *buffer);
> > +
> >  	Camera *camera_;
> >  	PipelineHandler *pipe_;
> >  	std::list<Request *> queuedRequests_;
> > diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
> > index f9ae767d529d44d9..d70e286661aded8e 100644
> > --- a/src/libcamera/pipeline_handler.cpp
> > +++ b/src/libcamera/pipeline_handler.cpp
> > @@ -58,6 +58,16 @@ LOG_DEFINE_CATEGORY(Pipeline)
> >   * exists.
> >   */
> >  
> > +Request *CameraData::requestFromBuffer(Buffer *buffer)
> > +{
> > +	for (Request *request : queuedRequests_)
> > +		for (const auto &it : request->buffers())
> > +			if (it.second == buffer)
> > +				return request;
> > +
> > +	return nullptr;
> > +}
> > +
> >  /**
> >   * \var CameraData::camera_
> >   * \brief The camera related to this CameraData instance
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Regards,
Niklas Söderlund