libcamera: Rename YamlObject to ValueNode

The YamlObject class is now a generic data container to model trees of
values. Rename it to ValueNode and expand the class documentation.

While at it, drop the unneeded libcamera:: namespace prefix when using
the ValueNode class.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>

include/libcamera/internal/converter/converter_dw100.h

@@ -31,7 +31,7 @@ public:
 
 	static std::unique_ptr<ConverterDW100Module> createModule(DeviceEnumerator *enumerator);
 
-	int init(const YamlObject &params);
+	int init(const ValueNode &params);
 
 	int configure(const StreamConfiguration &inputCfg,
 		      const std::vector<std::reference_wrapper<const StreamConfiguration>>

include/libcamera/internal/global_configuration.h

@@ -14,14 +14,14 @@
 
 #include <libcamera/base/utils.h>
 
-#include "libcamera/internal/yaml_object.h"
+#include "libcamera/internal/value_node.h"
 
 namespace libcamera {
 
 class GlobalConfiguration
 {
 public:
-	using Configuration = const YamlObject &;
+	using Configuration = const ValueNode &;
 
 	GlobalConfiguration();
 
@@ -32,7 +32,7 @@ public:
 	std::optional<T> option(
 		const std::initializer_list<std::string_view> confPath) const
 	{
-		const YamlObject *c = &configuration();
+		const ValueNode *c = &configuration();
 		for (auto part : confPath) {
 			c = &(*c)[part];
 			if (!*c)
@@ -55,8 +55,8 @@ private:
 	bool loadFile(const std::filesystem::path &fileName);
 	void load();
 
-	std::unique_ptr<YamlObject> yamlConfiguration_ =
-		std::make_unique<YamlObject>();
+	std::unique_ptr<ValueNode> yamlConfiguration_ =
+		std::make_unique<ValueNode>();
 };
 
 } /* namespace libcamera */

include/libcamera/internal/matrix.h

@@ -14,7 +14,7 @@
 #include <libcamera/base/log.h>
 #include <libcamera/base/span.h>
 
-#include "libcamera/internal/yaml_object.h"
+#include "libcamera/internal/value_node.h"
 
 namespace libcamera {
 
@@ -188,7 +188,7 @@ constexpr Matrix<T, Rows, Cols> operator+(const Matrix<T, Rows, Cols> &m1, const
 }
 
 #ifndef __DOXYGEN__
-bool matrixValidateYaml(const YamlObject &obj, unsigned int size);
+bool matrixValidateYaml(const ValueNode &obj, unsigned int size);
 #endif /* __DOXYGEN__ */
 
 #ifndef __DOXYGEN__
@@ -200,8 +200,8 @@ std::ostream &operator<<(std::ostream &out, const Matrix<T, Rows, Cols> &m)
 }
 
 template<typename T, unsigned int Rows, unsigned int Cols>
-struct YamlObject::Accessor<Matrix<T, Rows, Cols>> {
-	std::optional<Matrix<T, Rows, Cols>> get(const YamlObject &obj) const
+struct ValueNode::Accessor<Matrix<T, Rows, Cols>> {
+	std::optional<Matrix<T, Rows, Cols>> get(const ValueNode &obj) const
 	{
 		if (!matrixValidateYaml(obj, Rows * Cols))
 			return std::nullopt;
@@ -210,7 +210,7 @@ struct YamlObject::Accessor<Matrix<T, Rows, Cols>> {
 		T *data = &matrix[0][0];
 
 		unsigned int i = 0;
-		for (const YamlObject &entry : obj.asList()) {
+		for (const ValueNode &entry : obj.asList()) {
 			const auto value = entry.get<T>();
 			if (!value)
 				return std::nullopt;

include/libcamera/internal/meson.build

@@ -48,8 +48,8 @@ libcamera_internal_headers = files([
     'v4l2_request.h',
     'v4l2_subdevice.h',
     'v4l2_videodevice.h',
+    'value_node.h',
     'vector.h',
-    'yaml_object.h',
     'yaml_parser.h',
 ])
 

include/libcamera/internal/value_node.h

@@ -3,7 +3,7 @@
  * Copyright (C) 2022, Google Inc.
  * Copyright (C) 2026, Ideas on Board
  *
- * libcamera YAML object
+ * Data structure to manage tree of values
  */
 
 #pragma once
@@ -22,16 +22,16 @@
 
 namespace libcamera {
 
-class YamlObject
+class ValueNode
 {
 private:
 	struct Value {
-		Value(std::string k, std::unique_ptr<YamlObject> &&v)
+		Value(std::string k, std::unique_ptr<ValueNode> &&v)
 			: key(std::move(k)), value(std::move(v))
 		{
 		}
 		std::string key;
-		std::unique_ptr<YamlObject> value;
+		std::unique_ptr<ValueNode> value;
 	};
 
 	using ValueContainer = std::vector<Value>;
@@ -103,8 +103,8 @@ public:
 	class ListIterator : public Iterator<ListIterator>
 	{
 	public:
-		using value_type = const YamlObject &;
-		using pointer = const YamlObject *;
+		using value_type = const ValueNode &;
+		using pointer = const ValueNode *;
 		using reference = value_type;
 
 		value_type operator*() const
@@ -121,7 +121,7 @@ public:
 	class DictIterator : public Iterator<DictIterator>
 	{
 	public:
-		using value_type = std::pair<const std::string &, const YamlObject &>;
+		using value_type = std::pair<const std::string &, const ValueNode &>;
 		using pointer = value_type *;
 		using reference = value_type &;
 
@@ -142,8 +142,8 @@ public:
 	};
 #endif /* __DOXYGEN__ */
 
-	YamlObject();
-	~YamlObject();
+	ValueNode();
+	~ValueNode();
 
 	bool isValue() const
 	{
@@ -190,16 +190,16 @@ public:
 	DictAdapter asDict() const { return DictAdapter{ list_ }; }
 	ListAdapter asList() const { return ListAdapter{ list_ }; }
 
-	const YamlObject &operator[](std::size_t index) const;
+	const ValueNode &operator[](std::size_t index) const;
 
 	bool contains(std::string_view key) const;
-	const YamlObject &operator[](std::string_view key) const;
+	const ValueNode &operator[](std::string_view key) const;
 
-	YamlObject *add(std::unique_ptr<YamlObject> &&child);
-	YamlObject *add(std::string key, std::unique_ptr<YamlObject> &&child);
+	ValueNode *add(std::unique_ptr<ValueNode> &&child);
+	ValueNode *add(std::string key, std::unique_ptr<ValueNode> &&child);
 
 private:
-	LIBCAMERA_DISABLE_COPY_AND_MOVE(YamlObject)
+	LIBCAMERA_DISABLE_COPY_AND_MOVE(ValueNode)
 
 	template<typename T>
 	friend struct Accessor;
@@ -213,15 +213,15 @@ private:
 
 	template<typename T, typename Enable = void>
 	struct Accessor {
-		std::optional<T> get(const YamlObject &obj) const;
-		void set(YamlObject &obj, T value);
+		std::optional<T> get(const ValueNode &obj) const;
+		void set(ValueNode &obj, T value);
 	};
 
 	Type type_;
 
 	std::string value_;
 	ValueContainer list_;
-	std::map<std::string, YamlObject *, std::less<>> dictionary_;
+	std::map<std::string, ValueNode *, std::less<>> dictionary_;
 };
 
 } /* namespace libcamera */

include/libcamera/internal/vector.h

@@ -19,7 +19,7 @@
 #include <libcamera/base/span.h>
 
 #include "libcamera/internal/matrix.h"
-#include "libcamera/internal/yaml_object.h"
+#include "libcamera/internal/value_node.h"
 
 namespace libcamera {
 
@@ -329,7 +329,7 @@ bool operator!=(const Vector<T, Rows> &lhs, const Vector<T, Rows> &rhs)
 }
 
 #ifndef __DOXYGEN__
-bool vectorValidateYaml(const YamlObject &obj, unsigned int size);
+bool vectorValidateYaml(const ValueNode &obj, unsigned int size);
 #endif /* __DOXYGEN__ */
 
 #ifndef __DOXYGEN__
@@ -347,8 +347,8 @@ std::ostream &operator<<(std::ostream &out, const Vector<T, Rows> &v)
 }
 
 template<typename T, unsigned int Rows>
-struct YamlObject::Accessor<Vector<T, Rows>> {
-	std::optional<Vector<T, Rows>> get(const YamlObject &obj) const
+struct ValueNode::Accessor<Vector<T, Rows>> {
+	std::optional<Vector<T, Rows>> get(const ValueNode &obj) const
 	{
 		if (!vectorValidateYaml(obj, Rows))
 			return std::nullopt;
@@ -356,7 +356,7 @@ struct YamlObject::Accessor<Vector<T, Rows>> {
 		Vector<T, Rows> vector;
 
 		unsigned int i = 0;
-		for (const YamlObject &entry : obj.asList()) {
+		for (const ValueNode &entry : obj.asList()) {
 			const auto value = entry.get<T>();
 			if (!value)
 				return std::nullopt;

include/libcamera/internal/yaml_parser.h

@@ -9,7 +9,7 @@
 
 #include <memory>
 
-#include "libcamera/internal/yaml_object.h"
+#include "libcamera/internal/value_node.h"
 
 namespace libcamera {
 
@@ -18,7 +18,7 @@ class File;
 class YamlParser final
 {
 public:
-	static std::unique_ptr<YamlObject> parse(File &file);
+	static std::unique_ptr<ValueNode> parse(File &file);
 };
 
 } /* namespace libcamera */