Home | History | Annotate | Download | only in net_internals 
      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 var timeutil = (function() {
      6   'use strict';
      7 
      8   /**
      9    * Offset needed to convert event times to Date objects.
     10    * Updated whenever constants are loaded.
     11    */
     12   var timeTickOffset = 0;
     13 
     14   /**
     15    * Sets the offset used to convert tick counts to dates.
     16    */
     17   function setTimeTickOffset(offset) {
     18     // Note that the subtraction by 0 is to cast to a number (probably a float
     19     // since the numbers are big).
     20     timeTickOffset = offset - 0;
     21   }
     22 
     23   /**
     24    * The browser gives us times in terms of "time ticks" in milliseconds.
     25    * This function converts the tick count to a Javascript "time", which is
     26    * the UTC time in milliseconds.
     27    *
     28    * @param {string} timeTicks A time represented in "time ticks".
     29    * @return {number} The Javascript time that |timeTicks| represents.
     30    */
     31   function convertTimeTicksToTime(timeTicks) {
     32     return timeTickOffset + (timeTicks - 0);
     33   }
     34 
     35   /**
     36    * The browser gives us times in terms of "time ticks" in milliseconds.
     37    * This function converts the tick count to a Date() object.
     38    *
     39    * @param {string} timeTicks A time represented in "time ticks".
     40    * @return {Date} The time that |timeTicks| represents.
     41    */
     42   function convertTimeTicksToDate(timeTicks) {
     43     return new Date(convertTimeTicksToTime(timeTicks));
     44   }
     45 
     46   /**
     47    * Returns the current time.
     48    *
     49    * @return {number} Milliseconds since the Unix epoch.
     50    */
     51   function getCurrentTime() {
     52     return Date.now();
     53   }
     54 
     55   /**
     56    * Adds an HTML representation of |date| to |parentNode|.
     57    *
     58    * @param {DomNode} parentNode The node that will contain the new node.
     59    * @param {Date} date The date to be displayed.
     60    * @return {DomNode} The new node containing the date/time.
     61    */
     62   function addNodeWithDate(parentNode, date) {
     63     var span = addNodeWithText(parentNode, 'span', dateToString(date));
     64     span.title = 't=' + date.getTime();
     65     return span;
     66   }
     67 
     68   /**
     69    * Returns a string representation of |date|.
     70    *
     71    * @param {Date} date The date to be represented.
     72    * @return {string} A string representation of |date|.
     73    */
     74   function dateToString(date) {
     75     var dateStr = date.getFullYear() + '-' +
     76                   zeroPad_(date.getMonth() + 1, 2) + '-' +
     77                   zeroPad_(date.getDate(), 2);
     78 
     79     var timeStr = zeroPad_(date.getHours(), 2) + ':' +
     80                   zeroPad_(date.getMinutes(), 2) + ':' +
     81                   zeroPad_(date.getSeconds(), 2) + '.' +
     82                   zeroPad_(date.getMilliseconds(), 3);
     83 
     84     return dateStr + ' ' + timeStr;
     85   }
     86 
     87   /**
     88    * Prefixes enough zeros to |num| so that it has length |len|.
     89    * @param {number} num The number to be padded.
     90    * @param {number} len The desired length of the returned string.
     91    * @return {string} The zero-padded representation of |num|.
     92    */
     93   function zeroPad_(num, len) {
     94     var str = num + '';
     95     while (str.length < len)
     96       str = '0' + str;
     97     return str;
     98   }
     99 
    100   return {
    101     setTimeTickOffset: setTimeTickOffset,
    102     convertTimeTicksToTime: convertTimeTicksToTime,
    103     convertTimeTicksToDate: convertTimeTicksToDate,
    104     getCurrentTime: getCurrentTime,
    105     addNodeWithDate: addNodeWithDate,
    106     dateToString: dateToString
    107   };
    108 })();
    109