[libcamera-devel] [PATCH 2/3] cam: options: Add an array data type to OptionValue

[Niklas Söderlund]

Hi Jacopo,

On 2019-03-26 11:40:45 +0100, Jacopo Mondi wrote:
> Hi Niklas,
> 
> On Tue, Mar 26, 2019 at 11:35:25AM +0100, Niklas Söderlund wrote:
> > Hi Jacopo,
> >
> > Thanks for your feedback.
> >
> > On 2019-03-26 11:30:13 +0100, Jacopo Mondi wrote:
> > > Hi Niklas,
> > >
> > > On Tue, Mar 26, 2019 at 12:47:35AM +0100, Niklas Söderlund wrote:
> > > > To allow specifying the same argument option multiple times a new type
> > > > of OptionValue is needed. As parsing of options is an iterative process
> > > > there is a need to append options as they are parsed so instead of
> > > > setting values using the constructor a new add() method is used.
> > > >
> > > > Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> > > > ---
> > > >  src/cam/options.cpp | 19 +++++++++++++++++++
> > > >  src/cam/options.h   |  7 +++++++
> > > >  2 files changed, 26 insertions(+)
> > > >
> > > > diff --git a/src/cam/options.cpp b/src/cam/options.cpp
> > > > index 497833397d894f82..0dec154815d3cad5 100644
> > > > --- a/src/cam/options.cpp
> > > > +++ b/src/cam/options.cpp
> > > > @@ -272,6 +272,12 @@ OptionValue::OptionValue(const KeyValueParser::Options &value)
> > > >  {
> > > >  }
> > > >
> > > > +void OptionValue::add(const OptionValue &value)
> > > > +{
> > > > +	type_ = ValueArray;
> > > > +	array_.push_back(value);
> > > > +}
> > > > +
> > >
> > > I wonder how that would look like if we separate OptionValue (which
> > > holds the actual multi-type option value) from the array.
> > >
> > > I'm not expert of this code, but OptionBase has a 'values_' map, which
> > > associates the opt key with an OptionValue that holds the actually option
> > > value and this OptionValue, since this patch, could be an array too.
> > >
> > > I wonder how that would look like it the 'values_' map would use
> > > another type, which maintains OptionValues into a a vector, so that
> > > all OptionValues could be stored as array without introducing the new
> > > 'array_' field.
> > >
> > > Something like:
> > >
> > > class OptionBase
> > > {
> > >
> > >         ...
> > > 	std::map<T, OptionList> values_;
> > >
> > > };
> > >
> > > class OptionList
> > > {
> > >         ...
> > >         std::vector<OptionValue> array_;
> > > };
> > >
> > > class OptionValue
> > > {
> > >         ....
> > >         Hold the basic types as it did already;
> > > };
> > >
> > > Does this make any sense to you?
> >
> > That would have been a nice idea, if all options where arrays. As array
> > options are the exception, the main use-case is non-array options. Using
> > your suggestion a user of the parser would have to jump thru hoops to
> > access the non-array options by accessing them in a vector with 1
> > member, right?
> 
> Yes, they would be vectors with 1 member. Which part of handling a
> single entry vector concerns you? Insertion at parsing time or access
> to the option values?

None of the above. What concerns me is how the usage of the parser, 
right now and with the array additions uses still access non-array 
options as:

std::string name = options[OptCamera];

If everything was vectors it would need to be something like

std::string name = options[OptCamera].front();

Which is not a nice usage interface as the bulk of options would not be 
repeatable.

> 
> Thanks
>   j
> 
> >
> > >
> > > Thanks
> > >   j
> > >
> > > >  OptionValue::operator int() const
> > > >  {
> > > >  	return toInteger();
> > > > @@ -287,6 +293,11 @@ OptionValue::operator KeyValueParser::Options() const
> > > >  	return toKeyValues();
> > > >  }
> > > >
> > > > +OptionValue::operator std::vector<OptionValue>() const
> > > > +{
> > > > +	return toArray();
> > > > +}
> > > > +
> > > >  int OptionValue::toInteger() const
> > > >  {
> > > >  	if (type_ != ValueInteger)
> > > > @@ -311,6 +322,14 @@ KeyValueParser::Options OptionValue::toKeyValues() const
> > > >  	return keyValues_;
> > > >  }
> > > >
> > > > +std::vector<OptionValue> OptionValue::toArray() const
> > > > +{
> > > > +	if (type_ != ValueArray)
> > > > +		return std::vector<OptionValue>{};
> > > > +
> > > > +	return array_;
> > > > +}
> > > > +
> > > >  /* -----------------------------------------------------------------------------
> > > >   * OptionsParser
> > > >   */
> > > > diff --git a/src/cam/options.h b/src/cam/options.h
> > > > index b33a90fc6058febf..6a887416c0070c41 100644
> > > > --- a/src/cam/options.h
> > > > +++ b/src/cam/options.h
> > > > @@ -10,6 +10,7 @@
> > > >  #include <ctype.h>
> > > >  #include <list>
> > > >  #include <map>
> > > > +#include <vector>
> > > >
> > > >  class KeyValueParser;
> > > >  class OptionValue;
> > > > @@ -84,6 +85,7 @@ public:
> > > >  		ValueInteger,
> > > >  		ValueString,
> > > >  		ValueKeyValue,
> > > > +		ValueArray,
> > > >  	};
> > > >
> > > >  	OptionValue();
> > > > @@ -92,21 +94,26 @@ public:
> > > >  	OptionValue(const std::string &value);
> > > >  	OptionValue(const KeyValueParser::Options &value);
> > > >
> > > > +	void add(const OptionValue &value);
> > > > +
> > > >  	ValueType type() const { return type_; }
> > > >
> > > >  	operator int() const;
> > > >  	operator std::string() const;
> > > >  	operator KeyValueParser::Options() const;
> > > > +	operator std::vector<OptionValue>() const;
> > > >
> > > >  	int toInteger() const;
> > > >  	std::string toString() const;
> > > >  	KeyValueParser::Options toKeyValues() const;
> > > > +	std::vector<OptionValue> toArray() const;
> > > >
> > > >  private:
> > > >  	ValueType type_;
> > > >  	int integer_;
> > > >  	std::string string_;
> > > >  	KeyValueParser::Options keyValues_;
> > > > +	std::vector<OptionValue> array_;
> > > >  };
> > > >
> > > >  class OptionsParser
> > > > --
> > > > 2.21.0
> > > >
> > > > _______________________________________________
> > > > libcamera-devel mailing list
> > > > libcamera-devel at lists.libcamera.org
> > > > https://lists.libcamera.org/listinfo/libcamera-devel
> >
> >
> >
> > --
> > Regards,
> > Niklas Söderlund



-- 
Regards,
Niklas Söderlund