[PATCH] libcamera: controls: Add overwriteExisting parameter to ControlList::merge

[Stefan Klug]

Hi Umang,

thanks for your review. I'll post a updated patch soon.

Cheers,
Stefan

Am 04.03.24 um 05:48 schrieb Umang Jain:
> Hi Stefan,
> 
> Thank you for the patch.
> 
> On 29/02/24 10:27 pm, Stefan Klug wrote:
>> This is useful in many cases although not included in the stl.
>>
>> A typical usecase would be:
>> ContolList controls = getDefaults()
>> controls.merge(someSpecialValues, true)
>> ...
>>
>>
>> Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
>> ---
>>
>> Hey,
>>
>> this is my first email patch - hurray :-)
> 
> Great !
>> Cheers,
>> Stefan
>>
>>   include/libcamera/controls.h | 2 +-
>>   src/libcamera/controls.cpp   | 9 ++++++---
>>   2 files changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
>> index cf942055..0bf778d8 100644
>> --- a/include/libcamera/controls.h
>> +++ b/include/libcamera/controls.h
>> @@ -368,7 +368,7 @@ public:
>>       std::size_t size() const { return controls_.size(); }
>>         void clear() { controls_.clear(); }
>> -    void merge(const ControlList &source);
>> +    void merge(const ControlList &source, bool overwriteExisting =
>> false);
>>         bool contains(unsigned int id) const;
>>   diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
>> index b808116c..8ef29a96 100644
>> --- a/src/libcamera/controls.cpp
>> +++ b/src/libcamera/controls.cpp
>> @@ -910,10 +910,13 @@ ControlList::ControlList(const ControlInfoMap
>> &infoMap,
>>   /**
>>    * \brief Merge the \a source into the ControlList
>>    * \param[in] source The ControlList to merge into this object
>> + * \param[in] overwriteExisting Control if existing elements in *this
>> shall be
>> + * overwritten
>>    *
>>    * Merging two control lists copies elements from the \a source and
>> inserts
>>    * them in *this. If the \a source contains elements whose key is
>> already
>> - * present in *this, then those elements are not overwritten.
>> + * present in *this, then those elements are only overwritten if
>> + * overwriteExisting is true.
> 
> s/overwriteExisting/\a overwriteExisting/
>>    *
>>    * Only control lists created from the same ControlIdMap or
>> ControlInfoMap may
>>    * be merged. Attempting to do otherwise results in undefined
>> behaviour.
>> @@ -921,7 +924,7 @@ ControlList::ControlList(const ControlInfoMap
>> &infoMap,
>>    * \todo Reimplement or implement an overloaded version which
>> internally uses
>>    * std::unordered_map::merge() and accepts a non-const argument.
>>    */
>> -void ControlList::merge(const ControlList &source)
>> +void ControlList::merge(const ControlList &source, bool
>> overwriteExisting)
>>   {
>>       /**
>>        * \todo ASSERT that the current and source ControlList are derived
>> @@ -936,7 +939,7 @@ void ControlList::merge(const ControlList &source)
>>        */
>>         for (const auto &ctrl : source) {
>> -        if (contains(ctrl.first)) {
>> +        if (!overwriteExisting && contains(ctrl.first)) {
> 
> Looks good to me.
> 
> Stefan, can a small unit test can cover this as well? I see,
> 
>                 /*
>                  * Create a new list with a new control and merge it
> with the
>                  * existing one, verifying that the existing controls
>                  * values don't get overwritten.
>                  */
> 
> in test/controls/control_list.cpp, so probably worth adding this new
> behaviour as well, to that test.
>>               const ControlId *id = idmap_->at(ctrl.first);
>>               LOG(Controls, Warning)
>>                   << "Control " << id->name() << " not overwritten";
> 

-- 
Regards,

Stefan Klug