[libcamera-devel] [PATCH v2 1/7] libcamera: Add members to MediaEntity to support ancillary entities

[Daniel Scally]

Hi Laurent

On 04/12/2021 00:03, Laurent Pinchart wrote:
> Hi Daniel,
> 
> Thank you for the patch.
> 
> On Fri, Dec 03, 2021 at 10:42:24PM +0000, Daniel Scally wrote:
>> With kernel support for ancillary links, we can describe the
>> relationship between two devices represented individually as instances
>> of MediaEntity. As the only property of that relationship is its
>> existence, describe those relationships in libcamera simply as a
>> vector of MediaEntity pointers to the ancillary devices.
>>
>> Signed-off-by: Daniel Scally <djrscally at gmail.com>
>> ---
>> Changes in v2:
>>
>> 	- Switched from additional members against MediaLink pointing to the
>> 	primary and ancillary entity to a vector against MediaEntity holding
>> 	pointers to the ancillary entities linked to that MediaEntity (Laurent)
>>
>>  include/libcamera/internal/media_object.h |  4 ++++
>>  src/libcamera/media_object.cpp            | 16 ++++++++++++++++
>>  2 files changed, 20 insertions(+)
>>
>> diff --git a/include/libcamera/internal/media_object.h b/include/libcamera/internal/media_object.h
>> index 90c63598..48616a43 100644
>> --- a/include/libcamera/internal/media_object.h
>> +++ b/include/libcamera/internal/media_object.h
>> @@ -104,6 +104,9 @@ public:
>>  	unsigned int deviceMinor() const { return minor_; }
>>  
>>  	const std::vector<MediaPad *> &pads() const { return pads_; }
>> +	const std::vector<MediaEntity *> ancillaryEntities() const {return ancillaryEntities_; }
> 
> Missing space before return. checkstyle.py should have warned you (see
> Documentation/coding-style.rst for instructions to automate style
> checking with a git commit hook).

Ooh, that's quite a neat idea. Thanks

> 
>> +
>> +	void addAncillaryEntity(MediaEntity *ancillaryEntity);
> 
> As this is called by MediaDevice only, which is a friend of this class,
> you can make the function private.
> 

TIL of the friend concept - thanks. Still trying to get up to speed with
this whole cpp thing.

>>  
>>  	const MediaPad *getPadByIndex(unsigned int index) const;
>>  	const MediaPad *getPadById(unsigned int id) const;
>> @@ -129,6 +132,7 @@ private:
>>  	unsigned int minor_;
>>  
>>  	std::vector<MediaPad *> pads_;
>> +	std::vector<MediaEntity *> ancillaryEntities_;
>>  };
>>  
>>  } /* namespace libcamera */
>> diff --git a/src/libcamera/media_object.cpp b/src/libcamera/media_object.cpp
>> index f425d044..42b26b07 100644
>> --- a/src/libcamera/media_object.cpp
>> +++ b/src/libcamera/media_object.cpp
>> @@ -326,6 +326,22 @@ void MediaPad::addLink(MediaLink *link)
>>   * \return The list of the entity's pads
>>   */
>>  
>> +/**
>> + * \fn MediaEntity::ancillaryEntities()
>> + * \brief Retrieve all ancillary entities of the entity
>> + * \return The list of the entity's ancillary entities
>> + */
>> +
>> +/**
>> + * \brief Add a MediaEntity to the list of ancillary entities
>> + * \param[in] ancillaryEntity the instance of MediaEntity to add
> 
> s/the/The/
> 
>> + * \return void
> 
> No need for \return for functions that don't return anything.
> 
>> + */
>> +void MediaEntity::addAncillaryEntity(MediaEntity *ancillaryEntity)
>> +{
>> +	ancillaryEntities_.push_back(ancillaryEntity);
>> +}
>> +
>>  /**
>>   * \brief Get a pad in this entity by its index
>>   * \param[in] index The 0-based pad index
>