Log.cpp

#include <stdarg.h>
#include <string>
#include <errno.h>
#include <cstring>
#include <time.h>
#include "Log.h"
#include "ConstDef.h"
#include "Config.h"
using namespace std;

int Log::logLevel = LOG_WARNING;
FILE* Log::fp = NULL;
pthread_mutex_t Log::mutex;
char Log::curLogFileName[128] = {0};
string Log::logLevelitos[7] = {"FATAL_ERROR", "ERROR", "WARNING", "NOTICE", "INFO", "TRACE", "DEBUG"};

int Log::init(const int ll) {
	logLevel = ll;
	return 0;
}

string Log::getLogLevelStr(const int level) {
	return logLevelitos[level];
}

int Log::checkFile(const int year, const int mon, const int day){
	char newName[128] = {0};
	snprintf(newName, sizeof(newName), "%s%s.%4d%02d%02d", logPath.c_str(), 
		logFileNamePrefix.c_str(), year, mon, day);
	if (strcmp(curLogFileName, newName) == 0) {
		return 0;
	}
	//we need to touch a new log file
	else {
		if (fp) {
			pthread_mutex_lock(&mutex);
			//because multithread, so we need to compare again.
			if (fp){
				fclose(fp);
				fp = NULL;
			}
			pthread_mutex_unlock(&mutex);
		}		
		if (strcmp(curLogFileName, newName) != 0) {
			pthread_mutex_lock(&mutex);
			if (strcmp(curLogFileName, newName) != 0) {
				strcpy(curLogFileName, newName);
				fp = fopen(curLogFileName, "a");
				if (!fp) {
					fprintf(stderr, "Log file open failed. Path %s.  Error No:%s\n", curLogFileName, strerror(errno));
					pthread_mutex_unlock(&mutex);
					return -1;
				}
			}
			pthread_mutex_unlock(&mutex);
		}
	}
	return 0;
}

int Log::printLog(const char* fileName, const int line, const int level, const char* format, ...) {
	//we only log when the level input is lower than the loglevel in the config file
	if (level > logLevel) {
		return 0;
	}
	string logInfo = getLogLevelStr(level);
	//get the time
	time_t curTime;
	time(&curTime);
	struct tm* realTime = localtime(&curTime);

	char logBuf[1024] = {0};
	int charCount = snprintf(logBuf, sizeof(logBuf), "%4d/%02d/%02d %02d:%02d:%02d - [%s][%s %d] - ",
		realTime->tm_year + 1900, realTime->tm_mon + 1, realTime->tm_mday, realTime->tm_hour, 
		realTime->tm_min, realTime->tm_sec, logInfo.c_str(), fileName, line);
	//check weather we need change a log file
	if (checkFile(realTime->tm_year + 1900, realTime->tm_mon + 1, realTime->tm_mday) != 0) {
		return -1;
	}
	if (!fp) {
		return -1;
	}
	va_list argPtr;
	va_start(argPtr, format);
	vsnprintf(logBuf + charCount, sizeof(logBuf) - charCount, format, argPtr);
	va_end(argPtr);
	strcat(logBuf, "\n");
	pthread_mutex_lock(&mutex);
	fwrite(logBuf, sizeof(char), strlen(logBuf), fp);
	fflush(fp);
	pthread_mutex_unlock(&mutex);
	return 0;
}

void Log::closeLogFile() {
    if (fp && fp != stderr) {
        fclose(fp);
        fp = NULL;
        memset(curLogFileName, 0, 128);
    }
    return;
}