Sleds/K2Daemon/LogTrace.h

/*
 Modifications copyright (c)  2013 IOnU Security Inc. All rights reserved
 Added to IonU source repository in August 2013 by Kendrick Webster,
 based on public-domain code by Kendrick Webster.
-----------------------------------------------------------------------------
 Log trace message writer                                         2011 - 2013

 Written by Ken Webster <ken@kenwebster.org>
 [ other contributers can add their names here ]

 To the extent possible under law, the author(s) have dedicated all copyright
 and related and neighboring rights to this software to the public domain
 worldwide. This software is distributed without any warranty.

 See the CC0 Public Domain Dedication for details:
 <http://creativecommons.org/publicdomain/zero/1.0/>
-----------------------------------------------------------------------------
 Description

 This module defines and implements a simple platform-agnostic API suitable
 for producing log and trace messages in code that may be multi-threaded and
 timing-sensitive.  Messages are sent to UDP port 514 on the local host by
 default, but they can easily be sent elsewhere by editing this module's
 implementation.  Meta data for code execution tracing is automatically added
 (source file name, line number, elapsed time).
-----------------------------------------------------------------------------
 Usage

 A global function-like macro named 'logprintf' is used like the standard
 library printf() function except that it is not line-buffered.  Each call
 corresponds to one message, like the Unix/Linux syslog function.  Its
 first argument specifies the severity level:

 Log::
	emergency
	alert
	critical
	error
	warning
	notice
	informational
	debug          (default)
	debug2
	debug3

 The first 8 levels correspond to syslog severity levels.  This may be useful
 for interoperability with syslog or for re-using code that uses syslog.
---------------------------------------------------------------------------*/
#pragma once
#include <stdlib.h>
#include <string>

//-------------------------------------------------------------------------
// Severity levels
#define LOG_TRACE_SEVERITY_LEVELS \
	X(emergency,     EMG) \
	X(alert,         ALR) \
	X(critical,      CRI) \
	X(error,         ERR) \
	X(warning,       WRN) \
	X(notice,        NTC) \
	X(informational, INF) \
	X(debug,         DBG) \
	X(debug2,        DB2) \
	X(debug3,        DB3) \

namespace Log
{
	enum SeverityLevels
	{
#define X(level, abbrev) \
		level,
		LOG_TRACE_SEVERITY_LEVELS
#undef X
	};
	typedef enum SeverityLevels severity_t;
    
    extern severity_t FilterLevel;
}


//-------------------------------------------------------------------------
// logprintf() is called like printf(), but adding <severity> as 1st arg
//
// CAUTION: function argument expressions must not have side-effects
// -- evaluation is skipped if severity is less than the filter level
//
#define logprintf(severity, ...) \
   do {if (severity <= Log::FilterLevel) logprintf_1(__FILE__, __LINE__, severity, __VA_ARGS__);} while(0)

void logprintf_1(
	const char * source_file,
	unsigned int source_line,
	Log::severity_t severity,
	const char * format,
	...);

//-------------------------------------------------------------------------
// Hex dump
//
// CAUTION: function argument expressions must not have side-effects
// -- evaluation is skipped if severity is less than the filter level
//
#define loghexdump(severity, ...) \
    do {if (severity <= Log::FilterLevel) loghexdump_1(__FILE__, __LINE__, severity, __VA_ARGS__);} while(0)

void loghexdump_1(
	const char * source_file,
	unsigned int source_line,
	Log::severity_t severity,
	const void * d,
	size_t n);
	
	
// ---------- Log initialization and cleanup ----------
namespace Log
{
	typedef struct
	{
		bool echoToStdout;
		bool echoToSyslog;
		bool echoToUDP514;
		severity_t filterLevel; // messages with (severity > level) are dropped
        bool logToFile;
        std::string file;
        unsigned int nFilesMax;
        size_t nBytesPerFileMax;
        std::string shortIdentifier;
	}
	config_t;
    void Initialize(config_t* config);
    void Finalize(void);
}