[libcamera-devel] [PATCH v3 06/14] libcamera: controls: Extend ControlList to access controls by ID

[Laurent Pinchart]

The ControlList class implements a map from control specifier to control
ID. To avoid constant lookups of ControlInfo when using the class in the
libcamera core or in pipeline handlers, the map uses ControlInfo
pointers instead of ControlId values. This is however not very
convenient.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 include/libcamera/controls.h |  2 ++
 src/libcamera/controls.cpp   | 57 ++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index 9b37dfb16b89..d827318ee0fa 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -117,11 +117,13 @@ public:
 	const_iterator begin() const { return controls_.begin(); }
 	const_iterator end() const { return controls_.end(); }
 
+	bool contains(ControlId id) const;
 	bool contains(const ControlInfo *info) const { return controls_.count(info); };
 	bool empty() const { return controls_.empty(); }
 	std::size_t size() const { return controls_.size(); }
 	void clear() { controls_.clear(); }
 
+	ControlValue &operator[](ControlId id);
 	ControlValue &operator[](const ControlInfo *info) { return controls_[info]; }
 
 	void update(const ControlList &list);
diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index e4c41b97a354..17e09fc7f153 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -10,6 +10,8 @@
 #include <sstream>
 #include <string>
 
+#include <libcamera/camera.h>
+
 #include "log.h"
 #include "utils.h"
 
@@ -372,6 +374,30 @@ ControlList::ControlList(Camera *camera)
  * instance
  */
 
+/**
+ * \brief Check if the ist contains a control with the specified \a id
+ * \param[in] id The control ID
+ *
+ * The behaviour is undefined if the control \a id is not supported by the
+ * camera that the ControlList refers to.
+ *
+ * \return True if the list contains a matching control, false otherwise
+ */
+bool ControlList::contains(ControlId id) const
+{
+	const ControlInfoMap &controls = camera_->controls();
+	const auto iter = controls.find(id);
+	if (iter == controls.end()) {
+		LOG(Controls, Error)
+			<< "Camera " << camera_->name()
+			<< " does not support control " << id;
+
+		return false;
+	}
+
+	return controls_.find(&iter->second) != controls_.end();
+}
+
 /**
  * \fn ControlList::contains(const ControlInfo *info) const
  * \brief Check if the ist contains a control with the specified \a info
@@ -396,6 +422,34 @@ ControlList::ControlList(Camera *camera)
  * \brief Removes all controls from the list
  */
 
+/**
+ * \brief Access or insert the control specified by \a id
+ * \param[in] id The control ID
+ *
+ * This method returns a reference to the control identified by \a id, inserting
+ * it in the list if the ID is not already present.
+ *
+ * The behaviour is undefined if the control \a id is not supported by the
+ * camera that the ControlList refers to.
+ *
+ * \return A reference to the value of the control identified by \a id
+ */
+ControlValue &ControlList::operator[](ControlId id)
+{
+	const ControlInfoMap &controls = camera_->controls();
+	const auto iter = controls.find(id);
+	if (iter == controls.end()) {
+		LOG(Controls, Error)
+			<< "Camera " << camera_->name()
+			<< " does not support control " << id;
+
+		static ControlValue empty;
+		return empty;
+	}
+
+	return controls_[&iter->second];
+}
+
 /**
  * \fn ControlList::operator[](const ControlInfo *info)
  * \brief Access or insert the control specified by \a info
@@ -413,6 +467,9 @@ ControlList::ControlList(Camera *camera)
  *
  * Update all controls in the ControlList, by the values given by \a list
  * If the list already contains a control of this ID then it will be overwritten
+ *
+ * The behaviour is undefined if the two lists refer to different Camera
+ * instances.
  */
 void ControlList::update(const ControlList &list)
 {
-- 
Regards,

Laurent Pinchart