# Functions
InitFileLog initializes file based logging options.
InitLogger initializes PD's logger.
LogPanic logs the panic reason and stack, then exit the process.
StringToLogLevel translates log level string to log level.
StringToZapLogLevel translates log level string to log level.
# Structs
FileLogConfig serializes file log related config in toml/json.
LogConfig serializes log related config in toml/json.