Config: Flatten structures

Originally, Layer contained a std::map of Sections, which containted a std::map
containing the (key, value) pairs. Here we flattern this structure so that only
one std::map is required, reducing the number of indirections required and
vastly simplifying the code.

Source/Core/Common/Config/Layer.cpp

@@ -8,10 +8,47 @@
 
 #include "Common/Config/Config.h"
 #include "Common/Config/Layer.h"
-#include "Common/Config/Section.h"
 
 namespace Config
 {
+namespace detail
+{
+std::string ValueToString(u16 value)
+{
+  return StringFromFormat("0x%04x", value);
+}
+
+std::string ValueToString(u32 value)
+{
+  return StringFromFormat("0x%08x", value);
+}
+
+std::string ValueToString(float value)
+{
+  return StringFromFormat("%#.9g", value);
+}
+
+std::string ValueToString(double value)
+{
+  return StringFromFormat("%#.17g", value);
+}
+
+std::string ValueToString(int value)
+{
+  return std::to_string(value);
+}
+
+std::string ValueToString(bool value)
+{
+  return StringFromBool(value);
+}
+
+std::string ValueToString(const std::string& value)
+{
+  return value;
+}
+}
+
 ConfigLayerLoader::ConfigLayerLoader(LayerType layer) : m_layer(layer)
 {
 }
@@ -38,56 +75,44 @@ Layer::~Layer()
   Save();
 }
 
-bool Layer::Exists(System system, const std::string& section_name, const std::string& key)
+bool Layer::Exists(const ConfigLocation& location) const
 {
-  Section* section = GetSection(system, section_name);
-  if (!section)
-    return false;
-  return section->Exists(key);
+  const auto iter = m_map.find(location);
+  return iter != m_map.end() && iter->second.has_value();
 }
 
-bool Layer::DeleteKey(System system, const std::string& section_name, const std::string& key)
+bool Layer::DeleteKey(const ConfigLocation& location)
 {
-  Section* section = GetSection(system, section_name);
-  if (!section)
-    return false;
-  return section->Delete(key);
+  m_is_dirty = true;
+  bool had_value = m_map[location].has_value();
+  m_map[location].reset();
+  return had_value;
 }
 
-Section* Layer::GetSection(System system, const std::string& section_name)
+void Layer::DeleteAllKeys()
 {
-  for (auto& section : m_sections[system])
-    if (!strcasecmp(section->m_name.c_str(), section_name.c_str()))
-      return section.get();
-  return nullptr;
-}
-
-Section* Layer::GetOrCreateSection(System system, const std::string& section_name)
-{
-  Section* section = GetSection(system, section_name);
-  if (!section)
+  m_is_dirty = true;
+  for (auto& pair : m_map)
   {
-    m_sections[system].emplace_back(std::make_unique<Section>(m_layer, system, section_name));
-    section = m_sections[system].back().get();
+    pair.second.reset();
   }
-  return section;
 }
 
 void Layer::Load()
 {
   if (m_loader)
     m_loader->Load(this);
-  ClearDirty();
+  m_is_dirty = false;
   InvokeConfigChangedCallbacks();
 }
 
 void Layer::Save()
 {
-  if (!m_loader || !IsDirty())
+  if (!m_loader || !m_is_dirty)
     return;
 
   m_loader->Save(this);
-  ClearDirty();
+  m_is_dirty = false;
   InvokeConfigChangedCallbacks();
 }
 
@@ -98,22 +123,6 @@ LayerType Layer::GetLayer() const
 
 const LayerMap& Layer::GetLayerMap() const
 {
-  return m_sections;
-}
-
-bool Layer::IsDirty() const
-{
-  return std::any_of(m_sections.begin(), m_sections.end(), [](const auto& system) {
-    return std::any_of(system.second.begin(), system.second.end(),
-                       [](const auto& section) { return section->IsDirty(); });
-  });
-}
-
-void Layer::ClearDirty()
-{
-  std::for_each(m_sections.begin(), m_sections.end(), [](auto& system) {
-    std::for_each(system.second.begin(), system.second.end(),
-                  [](auto& section) { section->ClearDirty(); });
-  });
+  return m_map;
 }
 }