[libcamera-devel] [PATCH v3 3/4] ipa: raspberrypi: Add move/copy ctors and operators to Metadata class

[David Plowman]

Hi Naush

As per our discussion, it may be worthwhile including a merge (or
Merge) method. Something like "void Metadata::Merge(Metadata &other)".

This method would add any key/value pairs in the passed metadata
object "other" to "this" one. It could do so either by "moving" the
data values or by copying them. Presumably there are circumstances
where "moving" may be more efficient.

Such a method would help us to update the metadata correctly when we
elect not to run the control algorithms (one of the other patches in
this set). It would update all the sensor's metadata items, not just
the "device.status", preparing us for the day when we have sensors
that will generate such information.

Thanks!
David

On Sun, 18 Apr 2021 at 10:05, Naushir Patuck <naush at raspberrypi.com> wrote:
>
> Add a default, move and copy constructor as well as a move operator
> implementation RPiController::Metadata class.
>
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
> ---
>  src/ipa/raspberrypi/controller/metadata.hpp | 24 +++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/src/ipa/raspberrypi/controller/metadata.hpp b/src/ipa/raspberrypi/controller/metadata.hpp
> index 07dd28ed9e0a..319f2320fc70 100644
> --- a/src/ipa/raspberrypi/controller/metadata.hpp
> +++ b/src/ipa/raspberrypi/controller/metadata.hpp
> @@ -19,6 +19,21 @@ namespace RPiController {
>  class Metadata
>  {
>  public:
> +       Metadata() = default;
> +
> +       Metadata(Metadata const &other)
> +       {
> +               std::lock_guard<std::mutex> other_lock(other.mutex_);
> +               data_ = other.data_;
> +       }
> +
> +       Metadata(Metadata &&other)
> +       {
> +               std::lock_guard<std::mutex> other_lock(other.mutex_);
> +               data_ = std::move(other.data_);
> +               other.data_.clear();
> +       }
> +
>         template<typename T>
>         void Set(std::string const &tag, T const &value)
>         {
> @@ -51,6 +66,15 @@ public:
>                 return *this;
>         }
>
> +       Metadata &operator=(Metadata &&other)
> +       {
> +               std::lock_guard<std::mutex> lock(mutex_);
> +               std::lock_guard<std::mutex> other_lock(other.mutex_);
> +               data_ = std::move(other.data_);
> +               other.data_.clear();
> +               return *this;
> +       }
> +
>         template<typename T>
>         T *GetLocked(std::string const &tag)
>         {
> --
> 2.25.1
>