[libcamera-devel] [PATCH v3 1/5] libcamera: yaml_parser: Add getList() function

[Florian Sylvestre]

Allow to retrieve a YAML list of any already supported types in a std::vector.

Signed-off-by: Florian Sylvestre <fsylvestre at baylibre.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>
---
 include/libcamera/internal/yaml_parser.h | 16 ++++++
 src/libcamera/yaml_parser.cpp            | 66 ++++++++++++++++++++++++
 test/yaml-parser.cpp                     |  6 +++
 3 files changed, 88 insertions(+)

diff --git a/include/libcamera/internal/yaml_parser.h b/include/libcamera/internal/yaml_parser.h
index 064cf443..39161bbb 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_v<bool, T> ||
+			 std::is_same_v<double, T> ||
+			 std::is_same_v<int16_t, T> ||
+			 std::is_same_v<uint16_t, T> ||
+			 std::is_same_v<int32_t, T> ||
+			 std::is_same_v<uint32_t, T> ||
+			 std::is_same_v<std::string, T> ||
+			 std::is_same_v<Size, T>> * = nullptr>
+#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..125a348e 100644
--- a/src/libcamera/yaml_parser.cpp
+++ b/src/libcamera/yaml_parser.cpp
@@ -325,6 +325,72 @@ Size YamlObject::get(const Size &defaultValue, bool *ok) const
 
 #endif /* __DOXYGEN__ */
 
+/**
+ * \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<typename T,
+	 typename std::enable_if_t<
+		 std::is_same_v<bool, T> ||
+		 std::is_same_v<double, T> ||
+		 std::is_same_v<int16_t, T> ||
+		 std::is_same_v<uint16_t, T> ||
+		 std::is_same_v<int32_t, T> ||
+		 std::is_same_v<uint32_t, T> ||
+		 std::is_same_v<std::string, T> ||
+		 std::is_same_v<Size, T>> *>
+std::vector<T> YamlObject::getList(bool *ok) const
+{
+	setOk(ok, false);
+
+	if (type_ != Type::List)
+		return {};
+
+	std::vector<T> value;
+	value.reserve(list_.size());
+
+	/*
+	 * Provide somme dummy defaultValue to get() function and rely on the
+	 * ok variable to know if the parsing was correct.
+	 */
+	T defaultValue{};
+
+	for (const YamlObject &entry : asList()) {
+		bool result;
+		value.emplace_back(entry.get<T>(defaultValue, &result));
+		if (!result)
+			return {};
+	}
+
+	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__ */
+
 /**
  * \fn YamlObject::asDict() const
  * \brief Wrap a dictionary YamlObject in an adapter that exposes iterators
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