godot/core/io/logger.h

/*************************************************************************/
/*  logger.h                                                             */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
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#ifndef LOGGER_H
#define LOGGER_H

#include "core/os/file_access.h"
#include "core/string/ustring.h"
#include "core/templates/vector.h"

#include <stdarg.h>

class Logger {
protected:
	bool should_log(bool p_err);

	static bool _flush_stdout_on_print;

public:
	enum ErrorType {
		ERR_ERROR,
		ERR_WARNING,
		ERR_SCRIPT,
		ERR_SHADER
	};

	static void set_flush_stdout_on_print(bool value);

	virtual void logv(const char *p_format, va_list p_list, bool p_err) _PRINTF_FORMAT_ATTRIBUTE_2_0 = 0;
	virtual void log_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, ErrorType p_type = ERR_ERROR);

	void logf(const char *p_format, ...) _PRINTF_FORMAT_ATTRIBUTE_2_3;
	void logf_error(const char *p_format, ...) _PRINTF_FORMAT_ATTRIBUTE_2_3;

	virtual ~Logger() {}
};

/**
 * Writes messages to stdout/stderr.
 */
class StdLogger : public Logger {
public:
	virtual void logv(const char *p_format, va_list p_list, bool p_err) _PRINTF_FORMAT_ATTRIBUTE_2_0;
	virtual ~StdLogger() {}
};

/**
 * Writes messages to the specified file. If the file already exists, creates a copy (backup)
 * of it with timestamp appended to the file name. Maximum number of backups is configurable.
 * When maximum is reached, the oldest backups are erased. With the maximum being equal to 1,
 * it acts as a simple file logger.
 */
class RotatedFileLogger : public Logger {
	String base_path;
	int max_files;

	FileAccess *file = nullptr;

	void rotate_file_without_closing();
	void close_file();
	void clear_old_backups();
	void rotate_file();

public:
	RotatedFileLogger(const String &p_base_path, int p_max_files = 10);

	virtual void logv(const char *p_format, va_list p_list, bool p_err) _PRINTF_FORMAT_ATTRIBUTE_2_0;

	virtual ~RotatedFileLogger();
};

class CompositeLogger : public Logger {
	Vector<Logger *> loggers;

public:
	CompositeLogger(Vector<Logger *> p_loggers);

	virtual void logv(const char *p_format, va_list p_list, bool p_err) _PRINTF_FORMAT_ATTRIBUTE_2_0;
	virtual void log_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, ErrorType p_type = ERR_ERROR);

	void add_logger(Logger *p_logger);

	virtual ~CompositeLogger();
};

#endif // LOGGER_H