Initial commit

node_modules/ping/lib/parser/base.js

@@ -0,0 +1,203 @@
+'use strict';
+
+/* eslint no-unused-vars: 0 */
+
+var __ = require('underscore');
+
+/**
+ * Parsed response
+ * @typedef {object} PingResponse
+ * @param {string} inputHost - The input IP address or HOST
+ * @param {string} host - The input IP address or HOST
+ * @param {string} numeric_host - Target IP address
+ * @param {boolean} alive - True for existed host
+ * @param {string} output - Raw stdout from system ping
+ * @param {number} time - Time (float) in ms for first successful ping response
+ * @param {string} min - Minimum time for collection records
+ * @param {string} max - Maximum time for collection records
+ * @param {string} avg - Average time for collection records
+ * @param {number} packetLoss - Packet Losses in percent (number)
+ * @param {string} stddev - Standard deviation time for collected records
+ */
+
+/**
+ * @constructor
+ *
+ * @param {string} addr - Hostname or ip addres
+ * @param {PingConfig} config - Config object in probe()
+ */
+function parser(addr, config) {
+    // Initial state is 0
+    this._state = 0;
+
+    // Initial cache value
+    this._response = {
+        inputHost: addr,
+        host: 'unknown',
+        alive: false,
+        output: 'unknown',
+        time: 'unknown',
+        times: [],
+        min: 'unknown',
+        max: 'unknown',
+        avg: 'unknown',
+        stddev: 'unknown',
+        packetLoss: 'unknown',
+    };
+
+    // Initial times storage for ping time
+    this._times = [];
+
+    // Initial lines storage for ping output
+    this._lines = [];
+
+    // strip string regexp
+    this._stripRegex = /[ ]*\r?\n?$/g;
+
+    // Ping Config
+    this._pingConfig = config || {};
+}
+
+/**
+ * Enum for parser states
+ * @readonly
+ * @enum {number}
+ */
+parser.prototype.STATES = {
+    INIT: 0,
+    HEADER: 1,
+    BODY: 2,
+    FOOTER: 3,
+    END: 4,
+};
+
+/**
+ * Change state of this parser
+ * @param {number} state - parser.STATES
+ * @return {this} - This instance
+ */
+parser.prototype._changeState = function (state) {
+    var states = __.values(this.STATES);
+    if (states.indexOf(state) < 0) {
+        throw new Error('Unknown state');
+    }
+
+    this._state = state;
+
+    return this;
+};
+
+/**
+ * Process output's header
+ * @param {string} line - A line from system ping
+ */
+parser.prototype._processHeader = function (line) {
+    throw new Error('Subclass should implement this method');
+};
+
+/**
+ * Process output's body
+ * @param {string} line - A line from system ping
+ */
+parser.prototype._processBody = function (line) {
+    throw new Error('Subclass should implement this method');
+};
+
+/**
+ * Process output's footer
+ * @param {string} line - A line from system ping
+ */
+parser.prototype._processFooter = function (line) {
+    throw new Error('Subclass should implement this method');
+};
+
+/**
+ * Process a line from system ping
+ * @param {string} line - A line from system ping
+ * @return {this} - This instance
+ */
+parser.prototype.eat = function (line) {
+    var headerStates = [
+        this.STATES.INIT,
+        this.STATES.HEADER,
+    ];
+
+    // Store lines
+    this._lines.push(line);
+
+    // Strip all space \r\n at the end
+    var _line = line.replace(this._stripRegex, '');
+
+    if (_line.length === 0) {
+        // Do nothing if this is an empty line
+    } else if (headerStates.indexOf(this._state) >= 0) {
+        this._processHeader(_line);
+    } else if (this._state === this.STATES.BODY) {
+        this._processBody(_line);
+    } else if (this._state === this.STATES.FOOTER) {
+        this._processFooter(_line);
+    } else if (this._state === this.STATES.END) {
+        // Do nothing
+    } else {
+        throw new Error('Unknown state');
+    }
+
+    return this;
+};
+
+/**
+ * Get results after parsing certain lines from system ping
+ * @return {PingResponse} - Response from parsing ping output
+ */
+parser.prototype.getResult = function () {
+    var ret = __.extend({}, this._response);
+
+    // Concat output
+    ret.output = this._lines.join('\n');
+
+    // Determine alive
+    ret.alive = this._times.length > 0;
+
+    // Update time at first successful line
+    if (ret.alive) {
+        this._response.time = this._times[0];
+        ret.time = this._response.time;
+        this._response.times = this._times;
+        ret.times = this._response.times;
+    }
+
+    // Get stddev
+    if (
+        ret.stddev === 'unknown' && ret.alive
+    ) {
+        var numberOfSamples = this._times.length;
+
+        var sumOfAllSquareDifferences = __.reduce(
+            this._times,
+            function (memory, time) {
+                var differenceFromMean = time - ret.avg;
+                var squaredDifference =
+                    differenceFromMean * differenceFromMean;
+                return memory + squaredDifference;
+            },
+            0
+        );
+        var variances = sumOfAllSquareDifferences / numberOfSamples;
+
+        ret.stddev = Math.round(
+            Math.sqrt(variances) * 1000
+        ) / 1000;
+    }
+
+    // Fix min, avg, max, stddev up to 3 decimal points
+    __.each(['min', 'avg', 'max', 'stddev', 'packetLoss'], function (key) {
+        var v = ret[key];
+        if (__.isNumber(v)) {
+            ret[key] = v.toFixed(3);
+        }
+    });
+
+    return ret;
+};
+
+module.exports = parser;