ModernSettings.h

// Modern settings helper

#pragma once

#include<functional>
#include<map>
#include<memory>
#include<string>
#include<vector>

structBlob
{
constvoid* data = nullptr;
size_t size = 0;
};

classFile
{
public:
File(const WCHAR* fileName, DWORD desiredAccess, DWORD shareMode, DWORD creationDisposition = OPEN_EXISTING, DWORD flagsAndAttributes = FILE_ATTRIBUTE_NORMAL)
 {
 m_handle = ::CreateFile(fileName, desiredAccess, shareMode, nullptr, creationDisposition, flagsAndAttributes, nullptr);
 }

~File()
 {
if (m_handle != INVALID_HANDLE_VALUE)
::CloseHandle(m_handle);
 }

File(const File&) = delete;
 File& operator=(const File&) = delete;

explicitoperatorbool() const
 {
return (m_handle != INVALID_HANDLE_VALUE);
 }

operatorHANDLE() const
 {
return m_handle;
 }

uint64_tsize() const
 {
 LARGE_INTEGER li = {};
return ::GetFileSizeEx(m_handle, &li) ? li.QuadPart : (uint64_t)-1;
 }

private:
 HANDLE m_handle;
};

classMappedFile
{
public:
MappedFile(const WCHAR* fileName) : m_file(fileName, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_DELETE)
 {
if (m_file)
 {
auto mapping = ::CreateFileMapping(m_file, nullptr, PAGE_READONLY, 0, 0, nullptr);
if (mapping)
 {
 m_view.data = ::MapViewOfFile(mapping, FILE_MAP_READ, 0, 0, 0);
if (m_view.data)
 m_view.size = (size_t)m_file.size();

::CloseHandle(mapping);
 }
 }
 }

~MappedFile()
 {
if (m_view.data)
::UnmapViewOfFile(m_view.data);
 }

MappedFile(const MappedFile&) = delete;
 MappedFile& operator=(const MappedFile&) = delete;

explicitoperatorbool() const
 {
return (m_view.data != nullptr);
 }

 Blob get() const
 {
return m_view;
 }

private:
 File m_file;
 Blob m_view;
};

classModernSettings
{
public:
ModernSettings(constwchar_t* fname);

size_tsize() const
 {
return m_settings.size();
 }

structSetting
 {
 std::wstring_view fileName;

 std::wstring_view deepLink;
 std::wstring_view icon;
 std::wstring_view glyph;

 std::wstring_view pageId;
 std::wstring_view hostId;
 std::wstring_view groupId;
 std::wstring_view settingId;
 std::wstring_view description;
 std::wstring_view keywords;

Setting() = default;
Setting(const Blob& blob);
Setting(const std::vector<uint8_t>& blob) : Setting(Blob{ blob.data(), blob.size() }) {}

explicitoperatorbool() const
 {
return !fileName.empty();
 }
 };

 std::vector<std::wstring_view> enumerate() const;
 Setting get(const std::wstring_view& name) const;

private:
 MappedFile m_storage;
 std::map<std::wstring_view, Blob> m_settings;
};

// retrieve actual instance of ModernSettings
std::shared_ptr<ModernSettings> GetModernSettings();