dolphin/Source/Core/Common/SettingsHandler.cpp

146 lines
3.7 KiB
C++

// Copyright 2012 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
// Thanks to Treeki for writing the original class - 29/01/2012
#include "Common/SettingsHandler.h"
#include <algorithm>
#include <cstddef>
#include <ctime>
#include <iomanip>
#include <string>
#include <fmt/chrono.h>
#include "Common/CommonTypes.h"
namespace Common
{
SettingsHandler::SettingsHandler()
{
Reset();
}
SettingsHandler::SettingsHandler(Buffer&& buffer)
{
SetBytes(std::move(buffer));
}
const SettingsHandler::Buffer& SettingsHandler::GetBytes() const
{
return m_buffer;
}
void SettingsHandler::SetBytes(Buffer&& buffer)
{
Reset();
m_buffer = std::move(buffer);
Decrypt();
}
std::string SettingsHandler::GetValue(std::string_view key) const
{
constexpr char delim[] = "\n";
std::string toFind = std::string(delim).append(key).append("=");
size_t found = decoded.find(toFind);
if (found != std::string_view::npos)
{
size_t delimFound = decoded.find(delim, found + toFind.length());
if (delimFound == std::string_view::npos)
delimFound = decoded.length() - 1;
return decoded.substr(found + toFind.length(), delimFound - (found + toFind.length()));
}
else
{
toFind = std::string(key).append("=");
found = decoded.find(toFind);
if (found == 0)
{
size_t delimFound = decoded.find(delim, found + toFind.length());
if (delimFound == std::string_view::npos)
delimFound = decoded.length() - 1;
return decoded.substr(found + toFind.length(), delimFound - (found + toFind.length()));
}
}
return "";
}
void SettingsHandler::Decrypt()
{
const u8* str = m_buffer.data();
while (m_position < m_buffer.size())
{
decoded.push_back((u8)(m_buffer[m_position] ^ m_key));
m_position++;
str++;
m_key = (m_key >> 31) | (m_key << 1);
}
// The decoded data normally uses CRLF line endings, but occasionally
// (see the comment in WriteLine), lines can be separated by CRLFLF.
// To handle this, we remove every CR and treat LF as the line ending.
// (We ignore empty lines.)
decoded.erase(std::remove(decoded.begin(), decoded.end(), '\x0d'), decoded.end());
}
void SettingsHandler::Reset()
{
decoded = "";
m_position = 0;
m_key = INITIAL_SEED;
m_buffer = {};
}
void SettingsHandler::AddSetting(const std::string& key, const std::string& value)
{
WriteLine(key + '=' + value + "\r\n");
}
void SettingsHandler::WriteLine(const std::string& str)
{
const u32 old_position = m_position;
const u32 old_key = m_key;
// Encode and write the line
for (char c : str)
WriteByte(c);
// If the encoded data contains a null byte, Nintendo's decoder will stop at that null byte
// instead of decoding all the data. To avoid this: If the data we just wrote contains
// a null byte, add an LF right before the line to prod the values into being different,
// just like Nintendo does. Due to the chosen key, LF itself never encodes into a null byte.
const auto begin = m_buffer.cbegin() + old_position;
const auto end = m_buffer.cbegin() + m_position;
if (std::find(begin, end, 0) != end)
{
m_key = old_key;
m_position = old_position;
WriteByte('\n');
WriteLine(str);
}
}
void SettingsHandler::WriteByte(u8 b)
{
if (m_position >= m_buffer.size())
return;
m_buffer[m_position] = b ^ m_key;
m_position++;
m_key = (m_key >> 31) | (m_key << 1);
}
std::string SettingsHandler::GenerateSerialNumber()
{
const std::time_t t = std::time(nullptr);
// Must be 9 characters at most; otherwise the serial number will be rejected by SDK libraries,
// as there is a check to ensure the string length is strictly lower than 10.
// 3 for %j, 2 for %H, 2 for %M, 2 for %S.
return fmt::format("{:%j%H%M%S}", fmt::localtime(t));
}
} // namespace Common