libcamera: controls: Return control by value

The ControlList::get() and ControlValue::get() methods return the
control value by reference. This requires the ControlValue class to
store the control value in the same form as the one returned by those
functions. For the array controls that are soon to be added, the
ControlValue class would need to store a span<> instance in addition to
the control value itself, which would increase the required storage
space.

Prepare for support of array controls by returning from get() by value.
As all control values are 8 bytes at most, this doesn't affect
efficiency negatively.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
This commit is contained in:
Laurent Pinchart 2020-02-15 22:44:03 +02:00
parent cd04b9a96c
commit 5eaf4fed19
2 changed files with 9 additions and 11 deletions

View file

@ -42,7 +42,7 @@ public:
} }
template<typename T> template<typename T>
const T &get() const; T get() const;
template<typename T> template<typename T>
void set(const T &value); void set(const T &value);
@ -212,13 +212,11 @@ public:
bool contains(unsigned int id) const; bool contains(unsigned int id) const;
template<typename T> template<typename T>
const T &get(const Control<T> &ctrl) const T get(const Control<T> &ctrl) const
{ {
const ControlValue *val = find(ctrl.id()); const ControlValue *val = find(ctrl.id());
if (!val) { if (!val)
static T t(0); return T{};
return t;
}
return val->get<T>(); return val->get<T>();
} }

View file

@ -160,7 +160,7 @@ bool ControlValue::operator==(const ControlValue &other) const
*/ */
/** /**
* \fn template<typename T> const T &ControlValue::get() const * \fn template<typename T> T ControlValue::get() const
* \brief Get the control value * \brief Get the control value
* *
* The control value type shall match the type T, otherwise the behaviour is * The control value type shall match the type T, otherwise the behaviour is
@ -177,7 +177,7 @@ bool ControlValue::operator==(const ControlValue &other) const
#ifndef __DOXYGEN__ #ifndef __DOXYGEN__
template<> template<>
const bool &ControlValue::get<bool>() const bool ControlValue::get<bool>() const
{ {
ASSERT(type_ == ControlTypeBool); ASSERT(type_ == ControlTypeBool);
@ -185,7 +185,7 @@ const bool &ControlValue::get<bool>() const
} }
template<> template<>
const int32_t &ControlValue::get<int32_t>() const int32_t ControlValue::get<int32_t>() const
{ {
ASSERT(type_ == ControlTypeInteger32); ASSERT(type_ == ControlTypeInteger32);
@ -193,7 +193,7 @@ const int32_t &ControlValue::get<int32_t>() const
} }
template<> template<>
const int64_t &ControlValue::get<int64_t>() const int64_t ControlValue::get<int64_t>() const
{ {
ASSERT(type_ == ControlTypeInteger64); ASSERT(type_ == ControlTypeInteger64);
@ -720,7 +720,7 @@ bool ControlList::contains(unsigned int id) const
} }
/** /**
* \fn template<typename T> const T &ControlList::get(const Control<T> &ctrl) const * \fn template<typename T> T ControlList::get(const Control<T> &ctrl) const
* \brief Get the value of control \a ctrl * \brief Get the value of control \a ctrl
* \param[in] ctrl The control * \param[in] ctrl The control
* *