peya-nodejs-pool/lib/logger.js

/**
 * Cryptonote Node.JS Pool
 * https://github.com/dvandal/cryptonote-nodejs-pool
 *
 * Log system
 **/

// Load required modules
let fs = require('fs');
let util = require('util');
let dateFormat = require('dateformat');
let clc = require('cli-color');

/**
 * Initialize log system
 **/

// Set CLI colors
let severityMap = {
	'info': clc.blue,
	'warn': clc.yellow,
	'error': clc.red
};

// Set severity levels
let severityLevels = ['info', 'warn', 'error'];

// Set log directory
let logDir = config.logging.files.directory;

// Create log directory if not exists
if (!fs.existsSync(logDir)) {
	try {
		fs.mkdirSync(logDir);
	} catch (e) {
		throw e;
	}
}

/**
 * Write log entries to file at specified flush interval
 **/
let pendingWrites = {};

setInterval(function () {
	for (let fileName in pendingWrites) {
		let data = pendingWrites[fileName];
		fs.appendFile(fileName, data, function (err) {
			if (err) {
				console.log("Error writing log data to disk: %s", err);
				callback(null, "Error writing data to disk");
			}
		});
		delete pendingWrites[fileName];
	}
}, config.logging.files.flushInterval * 1000);

/**
 * Add new log entry
 **/
global.log = function (severity, system, text, data) {

	let logConsole = severityLevels.indexOf(severity) >= severityLevels.indexOf(config.logging.console.level);
	let logFiles = severityLevels.indexOf(severity) >= severityLevels.indexOf(config.logging.files.level);

	if (!logConsole && !logFiles) return;

	let time = dateFormat(new Date(), 'yyyy-mm-dd HH:MM:ss');
	let formattedMessage = text;

	if (data) {
		data.unshift(text);
		formattedMessage = util.format.apply(null, data);
	}

	if (logConsole) {
		if (config.logging.console.colors)
			if (system === 'daemon' || system === 'miningSource' || system === 'chainObserver') {
				console.log(severityMap[severity](time) + clc.green.bold(' [' + system + '] ' + formattedMessage));
			}
		else {
			console.log(severityMap[severity](time) + clc.white.bold(' [' + system + '] ') + formattedMessage);
		} else
			console.log(time + ' [' + system + '] ' + formattedMessage);
	}


	if (logFiles) {
		let fileName = logDir + '/' + system + '_' + severity + '.log';
		let fileLine = time + ' ' + formattedMessage + '\n';
		pendingWrites[fileName] = (pendingWrites[fileName] || '') + fileLine;
	}
};