citra/src/common/logging/backend.h
2018-03-16 11:18:06 +08:00

126 lines
3.2 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <chrono>
#include <cstdarg>
#include <memory>
#include <string>
#include <utility>
#include <boost/optional.hpp>
#include "common/file_util.h"
#include "common/logging/filter.h"
#include "common/logging/log.h"
namespace Log {
class Filter;
/**
* A log entry. Log entries are store in a structured format to permit more varied output
* formatting on different frontends, as well as facilitating filtering and aggregation.
*/
struct Entry {
std::chrono::microseconds timestamp;
Class log_class;
Level log_level;
std::string filename;
unsigned int line_num;
std::string function;
std::string message;
Entry() = default;
Entry(Entry&& o) = default;
Entry& operator=(Entry&& o) = default;
Entry& operator=(const Entry& o) = default;
};
/**
* Interface for logging backends. As loggers can be created and removed at runtime, this can be
* used by a frontend for adding a custom logging backend as needed
*/
class Backend {
public:
virtual ~Backend() = default;
virtual void SetFilter(const Filter& new_filter) {
filter = new_filter;
}
virtual const char* GetName() const = 0;
virtual void Write(const Entry& entry) = 0;
private:
Filter filter;
};
/**
* Backend that writes to stderr without any color commands
*/
class ConsoleBackend : public Backend {
public:
const char* GetName() const override {
return "console";
}
void Write(const Entry& entry) override;
};
/**
* Backend that writes to stderr and with color
*/
class ColorConsoleBackend : public Backend {
public:
const char* GetName() const override {
return "color_console";
}
void Write(const Entry& entry) override;
};
/**
* Backend that writes to a file passed into the constructor
*/
class FileBackend : public Backend {
public:
explicit FileBackend(const std::string& filename) : file(filename, "w") {}
const char* GetName() const override {
return "file";
}
void Write(const Entry& entry) override;
private:
FileUtil::IOFile file;
};
void AddBackend(std::unique_ptr<Backend> backend);
void RemoveBackend(const std::string& backend_name);
boost::optional<Backend*> GetBackend(const std::string& backend_name);
/**
* Returns the name of the passed log class as a C-string. Subclasses are separated by periods
* instead of underscores as in the enumeration.
*/
const char* GetLogClassName(Class log_class);
/**
* Returns the name of the passed log level as a C-string.
*/
const char* GetLevelName(Level log_level);
/// Creates a log entry by formatting the given source location, and message.
Entry CreateEntry(Class log_class, Level log_level, const char* filename, unsigned int line_nr,
const char* function, std::string message);
/**
* The global filter will prevent any messages from even being processed if they are filtered. Each
* backend can have a filter, but if the level is lower than the global filter, the backend will
* never get the message
*/
void SetGlobalFilter(const Filter& filter);
} // namespace Log