[libcamera-devel] [PATCH 04/10] libcamera: v4l2_controls: Index V4L2ControlInfoMap by ControlId *

Laurent Pinchart laurent.pinchart at ideasonboard.com
Tue Oct 15 17:31:18 CEST 2019


Hi Jacopo,

On Tue, Oct 15, 2019 at 05:16:06PM +0200, Jacopo Mondi wrote:
> On Mon, Oct 14, 2019 at 02:27:50AM +0300, Laurent Pinchart wrote:
> > To bring the libcamera and V4L2 control info maps closer, index the
> > latter by ControlId * like the former. As V4L2ControlInfoMap is widely
> > indexed by V4L2 numerical IDs, add accessors based on numerical IDs.
> >
> > This allows complete removal of the ControId pointer from the
> > V4L2ControlInfo, as the ControId is accessible as the key when iterating
> > over the map. A handful of users have to be modified to adapt to the
> > change.
> >
> > The controlInfo argument from V4L2Device::updateControls() can also be
> > removed as it itsn't used anymore.
> 
> Great! I had this in my early serialization work and I really wanted
> to see the v4l2_device control handling simplified
> 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  src/libcamera/include/v4l2_controls.h | 40 +++++++++------
> >  src/libcamera/include/v4l2_device.h   |  1 -
> >  src/libcamera/pipeline/uvcvideo.cpp   |  2 +-
> >  src/libcamera/pipeline/vimc.cpp       |  2 +-
> >  src/libcamera/v4l2_controls.cpp       | 71 +++++++++++++++++++++------
> >  src/libcamera/v4l2_device.cpp         | 25 +++-------
> >  6 files changed, 92 insertions(+), 49 deletions(-)
> >
> > diff --git a/src/libcamera/include/v4l2_controls.h b/src/libcamera/include/v4l2_controls.h
> > index 4d7ac1a133c7..ca7217501256 100644
> > --- a/src/libcamera/include/v4l2_controls.h
> > +++ b/src/libcamera/include/v4l2_controls.h
> > @@ -28,31 +28,41 @@ public:
> >  class V4L2ControlInfo
> >  {
> >  public:
> > -	V4L2ControlInfo(const V4L2ControlId &id,
> > -			const struct v4l2_query_ext_ctrl &ctrl);
> > +	V4L2ControlInfo(const struct v4l2_query_ext_ctrl &ctrl);
> >
> > -	const ControlId &id() const { return *id_; }
> >  	const ControlRange &range() const { return range_; }
> >
> >  private:
> > -	const V4L2ControlId *id_;
> >  	ControlRange range_;
> >  };
> >
> > -class V4L2ControlInfoMap : private std::map<unsigned int, V4L2ControlInfo>
> > +class V4L2ControlInfoMap : private std::map<const ControlId *, V4L2ControlInfo>
> >  {
> >  public:
> > -	V4L2ControlInfoMap &operator=(std::map<unsigned int, V4L2ControlInfo> &&info);
> > +	V4L2ControlInfoMap &operator=(std::map<const ControlId *, V4L2ControlInfo> &&info);
> >
> > -	using std::map<unsigned int, V4L2ControlInfo>::begin;
> > -	using std::map<unsigned int, V4L2ControlInfo>::cbegin;
> > -	using std::map<unsigned int, V4L2ControlInfo>::end;
> > -	using std::map<unsigned int, V4L2ControlInfo>::cend;
> > -	using std::map<unsigned int, V4L2ControlInfo>::at;
> > -	using std::map<unsigned int, V4L2ControlInfo>::empty;
> > -	using std::map<unsigned int, V4L2ControlInfo>::size;
> > -	using std::map<unsigned int, V4L2ControlInfo>::count;
> > -	using std::map<unsigned int, V4L2ControlInfo>::find;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::key_type;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::mapped_type;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::value_type;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::size_type;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::iterator;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::const_iterator;
> > +
> > +	using std::map<const ControlId *, V4L2ControlInfo>::begin;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::cbegin;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::end;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::cend;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::at;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::empty;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::size;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::count;
> > +	using std::map<const ControlId *, V4L2ControlInfo>::find;
> > +
> > +	mapped_type &at(unsigned int key);
> > +	const mapped_type &at(unsigned int key) const;
> > +	size_type count(unsigned int key) const;
> > +	iterator find(unsigned int key);
> > +	const_iterator find(unsigned int key) const;
> >
> >  	const ControlIdMap &idmap() const { return idmap_; }
> >
> > diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
> > index 5a5b85827f23..f30b1c2cde34 100644
> > --- a/src/libcamera/include/v4l2_device.h
> > +++ b/src/libcamera/include/v4l2_device.h
> > @@ -45,7 +45,6 @@ protected:
> >  private:
> >  	void listControls();
> >  	void updateControls(ControlList *ctrls,
> > -			    const V4L2ControlInfo **controlInfo,
> >  			    const struct v4l2_ext_control *v4l2Ctrls,
> >  			    unsigned int count);
> >
> > diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
> > index 547ad5ca4e55..4d76b5fd9347 100644
> > --- a/src/libcamera/pipeline/uvcvideo.cpp
> > +++ b/src/libcamera/pipeline/uvcvideo.cpp
> > @@ -340,7 +340,7 @@ int UVCCameraData::init(MediaEntity *entity)
> >  		const V4L2ControlInfo &info = ctrl.second;
> >  		const ControlId *id;
> >
> > -		switch (info.id().id()) {
> > +		switch (ctrl.first->id()) {
> >  		case V4L2_CID_BRIGHTNESS:
> >  			id = &controls::Brightness;
> >  			break;
> > diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
> > index 53d00360eb6e..78c0fe5ae509 100644
> > --- a/src/libcamera/pipeline/vimc.cpp
> > +++ b/src/libcamera/pipeline/vimc.cpp
> > @@ -416,7 +416,7 @@ int VimcCameraData::init(MediaDevice *media)
> >  		const V4L2ControlInfo &info = ctrl.second;
> >  		const ControlId *id;
> >
> > -		switch (info.id().id()) {
> > +		switch (ctrl.first->id()) {
> >  		case V4L2_CID_BRIGHTNESS:
> >  			id = &controls::Brightness;
> >  			break;
> > diff --git a/src/libcamera/v4l2_controls.cpp b/src/libcamera/v4l2_controls.cpp
> > index 12c4fb271ba5..9a5e4830db91 100644
> > --- a/src/libcamera/v4l2_controls.cpp
> > +++ b/src/libcamera/v4l2_controls.cpp
> > @@ -122,12 +122,9 @@ V4L2ControlId::V4L2ControlId(const struct v4l2_query_ext_ctrl &ctrl)
> >
> >  /**
> >   * \brief Construct a V4L2ControlInfo from a struct v4l2_query_ext_ctrl
> > - * \param[in] id The V4L2 control ID
> >   * \param[in] ctrl The struct v4l2_query_ext_ctrl as returned by the kernel
> >   */
> > -V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
> > -				 const struct v4l2_query_ext_ctrl &ctrl)
> > -	: id_(&id)
> > +V4L2ControlInfo::V4L2ControlInfo(const struct v4l2_query_ext_ctrl &ctrl)
> >  {
> >  	if (ctrl.type == V4L2_CTRL_TYPE_INTEGER64)
> >  		range_ = ControlRange(static_cast<int64_t>(ctrl.minimum),
> > @@ -137,12 +134,6 @@ V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
> >  				      static_cast<int32_t>(ctrl.maximum));
> >  }
> >
> > -/**
> > - * \fn V4L2ControlInfo::id()
> > - * \brief Retrieve the control ID
> > - * \return The V4L2 control ID
> > - */
> > -
> >  /**
> >   * \fn V4L2ControlInfo::range()
> >   * \brief Retrieve the control value range
> > @@ -151,7 +142,7 @@ V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
> >
> >  /**
> >   * \class V4L2ControlInfoMap
> > - * \brief A map of control ID to V4L2ControlInfo
> > + * \brief A map of controlID to V4L2ControlInfo
> >   */
> >
> >  /**
> > @@ -165,17 +156,69 @@ V4L2ControlInfo::V4L2ControlInfo(const V4L2ControlId &id,
> >   *
> >   * \return The populated V4L2ControlInfoMap
> >   */
> > -V4L2ControlInfoMap &V4L2ControlInfoMap::operator=(std::map<unsigned int, V4L2ControlInfo> &&info)
> > +V4L2ControlInfoMap &V4L2ControlInfoMap::operator=(std::map<const ControlId *, V4L2ControlInfo> &&info)
> >  {
> > -	std::map<unsigned int, V4L2ControlInfo>::operator=(std::move(info));
> > +	std::map<const ControlId *, V4L2ControlInfo>::operator=(std::move(info));
> >
> >  	idmap_.clear();
> >  	for (const auto &ctrl : *this)
> > -		idmap_[ctrl.first] = &ctrl.second.id();
> > +		idmap_[ctrl.first->id()] = ctrl.first;
> >
> >  	return *this;
> >  }
> >
> > +/**
> > + * \brief Access specified element by numerical ID
> > + * \param[in] id The numerical ID
> > + * \return A reference to the element whose ID is equal to \a id
> > + */
> > +V4L2ControlInfoMap::mapped_type &V4L2ControlInfoMap::at(unsigned int id)
> > +{
> > +	return at(idmap_.at(id));
> > +}
> > +
> > +/**
> > + * \brief Access specified element by numerical ID
> > + * \param[in] id The numerical ID
> > + * \return A const reference to the element whose ID is equal to \a id
> > + */
> > +const V4L2ControlInfoMap::mapped_type &V4L2ControlInfoMap::at(unsigned int id) const
> > +{
> > +	return at(idmap_.at(id));
> > +}
> > +
> > +/**
> > + * \brief Count the number of elements matching a numerical ID
> > + * \param[in] id The numerical ID
> > + * \return The number of elements matching the numerical \a id
> > + */
> > +V4L2ControlInfoMap::size_type V4L2ControlInfoMap::count(unsigned int id) const
> > +{
> > +	return count(idmap_.at(id));
> > +}
> 
> Can we have multiple elements indexed by the same id ?

That would require a V4L2 device to expose multiple controls with the
same ID. Highly unlikely given that the kernel API won't support this
:-)

> > +
> > +/**
> > + * \brief Find the element matching a numerical ID
> > + * \param[in] id The numerical ID
> > + * \return An iterator pointing to the element matching the numerical \a id, or
> > + * end() if no such element exists
> > + */
> > +V4L2ControlInfoMap::iterator V4L2ControlInfoMap::find(unsigned int id)
> > +{
> > +	return find(idmap_.at(id));
> > +}
> > +
> > +/**
> > + * \brief Find the element matching a numerical ID
> > + * \param[in] id The numerical ID
> > + * \return A const iterator pointing to the element matching the numerical
> > + * \a id, or end() if no such element exists
> > + */
> > +V4L2ControlInfoMap::const_iterator V4L2ControlInfoMap::find(unsigned int id) const
> > +{
> > +	return find(idmap_.at(id));
> > +}
> > +
> >  /**
> >   * \fn const ControlIdMap &V4L2ControlInfoMap::idmap() const
> >   * \brief Retrieve the ControlId map
> > diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> > index 144a60b4fe93..4bb7d5950f3a 100644
> > --- a/src/libcamera/v4l2_device.cpp
> > +++ b/src/libcamera/v4l2_device.cpp
> > @@ -171,7 +171,6 @@ int V4L2Device::getControls(ControlList *ctrls)
> >  	if (count == 0)
> >  		return 0;
> >
> > -	const V4L2ControlInfo *controlInfo[count];
> >  	struct v4l2_ext_control v4l2Ctrls[count];
> >  	memset(v4l2Ctrls, 0, sizeof(v4l2Ctrls));
> >
> > @@ -185,10 +184,7 @@ int V4L2Device::getControls(ControlList *ctrls)
> >  			return -EINVAL;
> >  		}
> >
> > -		const V4L2ControlInfo *info = &iter->second;
> > -		controlInfo[i] = info;
> >  		v4l2Ctrls[i].id = id->id();
> > -
> >  		i++;
> >  	}
> >
> > @@ -215,7 +211,7 @@ int V4L2Device::getControls(ControlList *ctrls)
> >  		ret = errorIdx;
> >  	}
> >
> > -	updateControls(ctrls, controlInfo, v4l2Ctrls, count);
> > +	updateControls(ctrls, v4l2Ctrls, count);
> >
> >  	return ret;
> >  }
> > @@ -249,7 +245,6 @@ int V4L2Device::setControls(ControlList *ctrls)
> >  	if (count == 0)
> >  		return 0;
> >
> > -	const V4L2ControlInfo *controlInfo[count];
> >  	struct v4l2_ext_control v4l2Ctrls[count];
> >  	memset(v4l2Ctrls, 0, sizeof(v4l2Ctrls));
> >
> > @@ -263,13 +258,11 @@ int V4L2Device::setControls(ControlList *ctrls)
> >  			return -EINVAL;
> >  		}
> >
> > -		const V4L2ControlInfo *info = &iter->second;
> > -		controlInfo[i] = info;
> >  		v4l2Ctrls[i].id = id->id();
> >
> >  		/* Set the v4l2_ext_control value for the write operation. */
> >  		const ControlValue &value = ctrl.second;
> > -		switch (info->id().type()) {
> > +		switch (id->type()) {
> >  		case ControlTypeInteger64:
> >  			v4l2Ctrls[i].value64 = value.get<int64_t>();
> >  			break;
> > @@ -308,7 +301,7 @@ int V4L2Device::setControls(ControlList *ctrls)
> >  		ret = errorIdx;
> >  	}
> >
> > -	updateControls(ctrls, controlInfo, v4l2Ctrls, count);
> > +	updateControls(ctrls, v4l2Ctrls, count);
> >
> >  	return ret;
> >  }
> > @@ -349,7 +342,7 @@ int V4L2Device::ioctl(unsigned long request, void *argp)
> >   */
> >  void V4L2Device::listControls()
> >  {
> > -	std::map<unsigned int, V4L2ControlInfo> ctrls;
> > +	std::map<const ControlId *, V4L2ControlInfo> ctrls;
> >  	struct v4l2_query_ext_ctrl ctrl = {};
> >
> >  	/* \todo Add support for menu and compound controls. */
> > @@ -388,8 +381,8 @@ void V4L2Device::listControls()
> >
> >  		controlIds_.emplace_back(utils::make_unique<V4L2ControlId>(ctrl));
> 
> Not in this patch but I just noticed: doesn't this create a
> V4L2ControlId while we should instead forward the argument to its
> constructor ? Well, I think the unique_ptr<> here plays a role, and I
> cannot suggest a way around it...

controlIds_ store instance of std::unique_ptr<>, so it doesn't construct
V4L2ControlId instances. This should, as far as I can tell, create a
single V4L2ControlId. The fact that ControlId copies are now impossible
is also a hint that no copy is taking place.

> Anyway, the change is good and desirable:
> Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
> 
> >  		ctrls.emplace(std::piecewise_construct,
> > -			      std::forward_as_tuple(ctrl.id),
> > -			      std::forward_as_tuple(*controlIds_.back().get(), ctrl));
> > +			      std::forward_as_tuple(controlIds_.back().get()),
> > +			      std::forward_as_tuple(ctrl));
> >  	}
> >
> >  	controls_ = std::move(ctrls);
> > @@ -399,12 +392,10 @@ void V4L2Device::listControls()
> >   * \brief Update the value of the first \a count V4L2 controls in \a ctrls using
> >   * values in \a v4l2Ctrls
> >   * \param[inout] ctrls List of V4L2 controls to update
> > - * \param[in] controlInfo List of V4L2 control information
> >   * \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 V4L2ControlInfo **controlInfo,
> >  				const struct v4l2_ext_control *v4l2Ctrls,
> >  				unsigned int count)
> >  {
> > @@ -414,10 +405,10 @@ void V4L2Device::updateControls(ControlList *ctrls,
> >  			break;
> >
> >  		const struct v4l2_ext_control *v4l2Ctrl = &v4l2Ctrls[i];
> > -		const V4L2ControlInfo *info = controlInfo[i];
> > +		const ControlId *id = ctrl.first;
> >  		ControlValue &value = ctrl.second;
> >
> > -		switch (info->id().type()) {
> > +		switch (id->type()) {
> >  		case ControlTypeInteger64:
> >  			value.set<int64_t>(v4l2Ctrl->value64);
> >  			break;

-- 
Regards,

Laurent Pinchart


More information about the libcamera-devel mailing list