[libcamera-devel] [PATCH 1/5] libcamera: yaml_parser: Add getList() function

[paul.elder at ideasonboard.com]

Hi Florian,

On Wed, Jun 22, 2022 at 05:19:14PM +0200, Florian Sylvestre via libcamera-devel wrote:
> Allow to retrieve a YAML list of any already supported types in a std::vector.
> 
> Signed-off-by: Florian Sylvestre <fsylvestre at baylibre.com>
> ---
>  include/libcamera/internal/yaml_parser.h | 16 ++++++
>  src/libcamera/yaml_parser.cpp            | 73 ++++++++++++++++++++++++
>  test/yaml-parser.cpp                     |  6 ++
>  3 files changed, 95 insertions(+)
> 
> diff --git a/include/libcamera/internal/yaml_parser.h b/include/libcamera/internal/yaml_parser.h
> index 064cf443..ea9189bd 100644
> --- a/include/libcamera/internal/yaml_parser.h
> +++ b/include/libcamera/internal/yaml_parser.h
> @@ -167,6 +167,22 @@ public:
>  #endif
>  	T get(const T &defaultValue, bool *ok = nullptr) const;
>  
> +#ifndef __DOXYGEN__
> +	template<typename T,
> +		 typename std::enable_if_t<
> +			 std::is_same<bool, T>::value ||
> +			 std::is_same<double, T>::value ||
> +			 std::is_same<int16_t, T>::value ||
> +			 std::is_same<uint16_t, T>::value ||
> +			 std::is_same<int32_t, T>::value ||
> +			 std::is_same<uint32_t, T>::value ||
> +			 std::is_same<std::string, T>::value ||
> +			 std::is_same<Size, T>::value> * = nullptr>

Should these be is_same_v ?


Otherwise, looks good.

Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>

> +#else
> +	template<typename T>
> +#endif
> +	std::vector<T> getList(bool *ok = nullptr) const;
> +
>  	DictAdapter asDict() const { return DictAdapter{ dictionary_ }; }
>  	ListAdapter asList() const { return ListAdapter{ list_ }; }
>  
> diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp
> index 5c45e44e..95c0038b 100644
> --- a/src/libcamera/yaml_parser.cpp
> +++ b/src/libcamera/yaml_parser.cpp
> @@ -117,6 +117,23 @@ std::size_t YamlObject::size() const
>   * \return Value as a bool type
>   */
>  
> +/**
> + * \fn template<typename T> YamlObject::getList<T>(
> + *	bool *ok) const
> + * \brief Parse the YamlObject as a list of \a T.
> + * \param[out] ok The result of whether the parse succeeded
> + *
> + * This function parses the value of the YamlObject as a list of \a T objects,
> + * and returns the value as a \a std::vector<T>. If parsing fails \a ok is set
> + * to false and a default empty vector is returned. Otherwise, the
> + * YamlObject list of values is returned, and \a ok is set to true.
> + *
> + * The \a ok pointer is optional and can be a nullptr if the caller doesn't
> + * need to know if parsing succeeded.
> + *
> + * \return Value as a std::vector<T> type
> + */
> +
>  #ifndef __DOXYGEN__
>  
>  template<>
> @@ -323,6 +340,62 @@ Size YamlObject::get(const Size &defaultValue, bool *ok) const
>  	return Size(width, height);
>  }
>  
> +template<typename T,
> +	 typename std::enable_if_t<
> +		 std::is_same<bool, T>::value ||
> +		 std::is_same<double, T>::value ||
> +		 std::is_same<int16_t, T>::value ||
> +		 std::is_same<uint16_t, T>::value ||
> +		 std::is_same<int32_t, T>::value ||
> +		 std::is_same<uint32_t, T>::value ||
> +		 std::is_same<std::string, T>::value ||
> +		 std::is_same<Size, T>::value> *>
> +std::vector<T> YamlObject::getList(bool *ok) const
> +{
> +	setOk(ok, false);
> +
> +	std::vector<T> defaultValue;
> +
> +	if (type_ != Type::List)
> +		return defaultValue;
> +
> +	std::vector<T> value = std::vector<T>(list_.size());
> +
> +	/*
> +	 * Provide somme dummy defaultValue to get() function
> +	 * and rely on the ok variable to know if the parsing
> +	 * was correct.
> +	 */
> +	T defaultArgument = T();
> +	bool result;
> +	for (unsigned int i = 0; i < list_.size(); ++i) {
> +		result = true;
> +		value[i] = list_[i]->get<T>(defaultArgument, &result);
> +
> +		if (!result)
> +			return defaultValue;
> +	}
> +
> +	setOk(ok, true);
> +	return value;
> +}
> +
> +template std::vector<bool> YamlObject::getList<bool>(bool *ok) const;
> +
> +template std::vector<double> YamlObject::getList<double>(bool *ok) const;
> +
> +template std::vector<int16_t> YamlObject::getList<int16_t>(bool *ok) const;
> +
> +template std::vector<uint16_t> YamlObject::getList<uint16_t>(bool *ok) const;
> +
> +template std::vector<int32_t> YamlObject::getList<int32_t>(bool *ok) const;
> +
> +template std::vector<uint32_t> YamlObject::getList<uint32_t>(bool *ok) const;
> +
> +template std::vector<std::string> YamlObject::getList<std::string>(bool *ok) const;
> +
> +template std::vector<Size> YamlObject::getList<Size>(bool *ok) const;
> +
>  #endif /* __DOXYGEN__ */
>  
>  /**
> diff --git a/test/yaml-parser.cpp b/test/yaml-parser.cpp
> index 38f84823..bb96a11b 100644
> --- a/test/yaml-parser.cpp
> +++ b/test/yaml-parser.cpp
> @@ -524,6 +524,12 @@ protected:
>  			return TestFail;
>  		}
>  
> +		std::vector<uint16_t> values = firstElement.getList<uint16_t>();
> +		if (values.size() != 2 || values[0] != 1 || values[1] != 2) {
> +			cerr << "getList() failed to return correct vector" << std::endl;
> +			return TestFail;
> +		}
> +
>  		auto &secondElement = level2Obj[1];
>  		if (!secondElement.isDictionary() ||
>  		    !secondElement.contains("one") ||
> -- 
> 2.34.1
>