resources/src/mediawiki/mediawiki.inspect.js

   1 /*!
   2  * Tools for inspecting page composition and performance.
   3  *
   4  * @author Ori Livneh
   5  * @since 1.22
   6  */
   7 /*jshint devel:true */
   8 ( function ( mw, $ ) {
   9
  10         var inspect,
  11                 hasOwn = Object.prototype.hasOwnProperty;
  12
  13         function sortByProperty( array, prop, descending ) {
  14                 var order = descending ? -1 : 1;
  15                 return array.sort( function ( a, b ) {
  16                         return a[prop] > b[prop] ? order : a[prop] < b[prop] ? -order : 0;
  17                 } );
  18         }
  19
  20         function humanSize( bytes ) {
  21                 if ( !$.isNumeric( bytes ) || bytes === 0 ) { return bytes; }
  22                 var i = 0, units = [ '', ' kB', ' MB', ' GB', ' TB', ' PB' ];
  23                 for ( ; bytes >= 1024; bytes /= 1024 ) { i++; }
  24                 return bytes.toFixed( 1 ) + units[i];
  25         }
  26
  27         /**
  28          * @class mw.inspect
  29          * @singleton
  30          */
  31         inspect = {
  32
  33                 /**
  34                  * Return a map of all dependency relationships between loaded modules.
  35                  *
  36                  * @return {Object} Maps module names to objects. Each sub-object has
  37                  *  two properties, 'requires' and 'requiredBy'.
  38                  */
  39                 getDependencyGraph: function () {
  40                         var modules = inspect.getLoadedModules(), graph = {};
  41
  42                         $.each( modules, function ( moduleIndex, moduleName ) {
  43                                 var dependencies = mw.loader.moduleRegistry[moduleName].dependencies || [];
  44
  45                                 if ( !hasOwn.call( graph, moduleName ) ) {
  46                                         graph[moduleName] = { requiredBy: [] };
  47                                 }
  48                                 graph[moduleName].requires = dependencies;
  49
  50                                 $.each( dependencies, function ( depIndex, depName ) {
  51                                         if ( !hasOwn.call( graph, depName ) ) {
  52                                                 graph[depName] = { requiredBy: [] };
  53                                         }
  54                                         graph[depName].requiredBy.push( moduleName );
  55                                 } );
  56                         } );
  57                         return graph;
  58                 },
  59
  60                 /**
  61                  * Calculate the byte size of a ResourceLoader module.
  62                  *
  63                  * @param {string} moduleName The name of the module
  64                  * @return {number|null} Module size in bytes or null
  65                  */
  66                 getModuleSize: function ( moduleName ) {
  67                         var module = mw.loader.moduleRegistry[ moduleName ],
  68                                 payload = 0;
  69
  70                         if ( mw.loader.getState( moduleName ) !== 'ready' ) {
  71                                 return null;
  72                         }
  73
  74                         if ( !module.style && !module.script ) {
  75                                 return null;
  76                         }
  77
  78                         // Tally CSS
  79                         if ( module.style && $.isArray( module.style.css ) ) {
  80                                 $.each( module.style.css, function ( i, stylesheet ) {
  81                                         payload += $.byteLength( stylesheet );
  82                                 } );
  83                         }
  84
  85                         // Tally JavaScript
  86                         if ( $.isFunction( module.script ) ) {
  87                                 payload += $.byteLength( module.script.toString() );
  88                         }
  89
  90                         return payload;
  91                 },
  92
  93                 /**
  94                  * Given CSS source, count both the total number of selectors it
  95                  * contains and the number which match some element in the current
  96                  * document.
  97                  *
  98                  * @param {string} css CSS source
  99                  * @return Selector counts
 100                  * @return {number} return.selectors Total number of selectors
 101                  * @return {number} return.matched Number of matched selectors
 102                  */
 103                 auditSelectors: function ( css ) {
 104                         var selectors = { total: 0, matched: 0 },
 105                                 style = document.createElement( 'style' ),
 106                                 sheet, rules;
 107
 108                         style.textContent = css;
 109                         document.body.appendChild( style );
 110                         // Standards-compliant browsers use .sheet.cssRules, IE8 uses .styleSheet.rules…
 111                         sheet = style.sheet || style.styleSheet;
 112                         rules = sheet.cssRules || sheet.rules;
 113                         $.each( rules, function ( index, rule ) {
 114                                 selectors.total++;
 115                                 if ( document.querySelector( rule.selectorText ) !== null ) {
 116                                         selectors.matched++;
 117                                 }
 118                         } );
 119                         document.body.removeChild( style );
 120                         return selectors;
 121                 },
 122
 123                 /**
 124                  * Get a list of all loaded ResourceLoader modules.
 125                  *
 126                  * @return {Array} List of module names
 127                  */
 128                 getLoadedModules: function () {
 129                         return $.grep( mw.loader.getModuleNames(), function ( module ) {
 130                                 return mw.loader.getState( module ) === 'ready';
 131                         } );
 132                 },
 133
 134                 /**
 135                  * Print tabular data to the console, using console.table, console.log,
 136                  * or mw.log (in declining order of preference).
 137                  *
 138                  * @param {Array} data Tabular data represented as an array of objects
 139                  *  with common properties.
 140                  */
 141                 dumpTable: function ( data ) {
 142                         try {
 143                                 // Bartosz made me put this here.
 144                                 if ( window.opera ) { throw window.opera; }
 145                                 // Use Function.prototype#call to force an exception on Firefox,
 146                                 // which doesn't define console#table but doesn't complain if you
 147                                 // try to invoke it.
 148                                 console.table.call( console, data );
 149                                 return;
 150                         } catch ( e ) {}
 151                         try {
 152                                 console.log( JSON.stringify( data, null, 2 ) );
 153                                 return;
 154                         } catch ( e ) {}
 155                         mw.log( data );
 156                 },
 157
 158                 /**
 159                  * Generate and print one more reports. When invoked with no arguments,
 160                  * print all reports.
 161                  *
 162                  * @param {string...} [reports] Report names to run, or unset to print
 163                  *  all available reports.
 164                  */
 165                 runReports: function () {
 166                         var reports = arguments.length > 0 ?
 167                                 Array.prototype.slice.call( arguments ) :
 168                                 $.map( inspect.reports, function ( v, k ) { return k; } );
 169
 170                         $.each( reports, function ( index, name ) {
 171                                 inspect.dumpTable( inspect.reports[name]() );
 172                         } );
 173                 },
 174
 175                 /**
 176                  * @class mw.inspect.reports
 177                  * @singleton
 178                  */
 179                 reports: {
 180                         /**
 181                          * Generate a breakdown of all loaded modules and their size in
 182                          * kilobytes. Modules are ordered from largest to smallest.
 183                          */
 184                         size: function () {
 185                                 // Map each module to a descriptor object.
 186                                 var modules = $.map( inspect.getLoadedModules(), function ( module ) {
 187                                         return {
 188                                                 name: module,
 189                                                 size: inspect.getModuleSize( module )
 190                                         };
 191                                 } );
 192
 193                                 // Sort module descriptors by size, largest first.
 194                                 sortByProperty( modules, 'size', true );
 195
 196                                 // Convert size to human-readable string.
 197                                 $.each( modules, function ( i, module ) {
 198                                         module.size = humanSize( module.size );
 199                                 } );
 200
 201                                 return modules;
 202                         },
 203
 204                         /**
 205                          * For each module with styles, count the number of selectors, and
 206                          * count how many match against some element currently in the DOM.
 207                          */
 208                         css: function () {
 209                                 var modules = [];
 210
 211                                 $.each( inspect.getLoadedModules(), function ( index, name ) {
 212                                         var css, stats, module = mw.loader.moduleRegistry[name];
 213
 214                                         try {
 215                                                 css = module.style.css.join();
 216                                         } catch ( e ) { return; } // skip
 217
 218                                         stats = inspect.auditSelectors( css );
 219                                         modules.push( {
 220                                                 module: name,
 221                                                 allSelectors: stats.total,
 222                                                 matchedSelectors: stats.matched,
 223                                                 percentMatched: stats.total !== 0 ?
 224                                                         ( stats.matched / stats.total * 100 ).toFixed( 2 )  + '%' : null
 225                                         } );
 226                                 } );
 227                                 sortByProperty( modules, 'allSelectors', true );
 228                                 return modules;
 229                         },
 230
 231                         /**
 232                          * Report stats on mw.loader.store: the number of localStorage
 233                          * cache hits and misses, the number of items purged from the
 234                          * cache, and the total size of the module blob in localStorage.
 235                          */
 236                         store: function () {
 237                                 var raw, stats = { enabled: mw.loader.store.enabled };
 238                                 if ( stats.enabled ) {
 239                                         $.extend( stats, mw.loader.store.stats );
 240                                         try {
 241                                                 raw = localStorage.getItem( mw.loader.store.getStoreKey() );
 242                                                 stats.totalSize = humanSize( $.byteLength( raw ) );
 243                                         } catch ( e ) {}
 244                                 }
 245                                 return [stats];
 246                         }
 247                 },
 248
 249                 /**
 250                  * Perform a string search across the JavaScript and CSS source code
 251                  * of all loaded modules and return an array of the names of the
 252                  * modules that matched.
 253                  *
 254                  * @param {string|RegExp} pattern String or regexp to match.
 255                  * @return {Array} Array of the names of modules that matched.
 256                  */
 257                 grep: function ( pattern ) {
 258                         if ( typeof pattern.test !== 'function' ) {
 259                                 // Based on Y.Escape.regex from YUI v3.15.0
 260                                 pattern = new RegExp( pattern.replace( /[\-$\^*()+\[\]{}|\\,.?\s]/g, '\\$&' ), 'g' );
 261                         }
 262
 263                         return $.grep( inspect.getLoadedModules(), function ( moduleName ) {
 264                                 var module = mw.loader.moduleRegistry[moduleName];
 265
 266                                 // Grep module's JavaScript
 267                                 if ( $.isFunction( module.script ) && pattern.test( module.script.toString() ) ) {
 268                                         return true;
 269                                 }
 270
 271                                 // Grep module's CSS
 272                                 if (
 273                                         $.isPlainObject( module.style ) && $.isArray( module.style.css )
 274                                         && pattern.test( module.style.css.join( '' ) )
 275                                 ) {
 276                                         // Module's CSS source matches
 277                                         return true;
 278                                 }
 279
 280                                 return false;
 281                         } );
 282                 }
 283         };
 284
 285         if ( mw.config.get( 'debug' ) ) {
 286                 mw.log( 'mw.inspect: reports are not available in debug mode.' );
 287         }
 288
 289         mw.inspect = inspect;
 290
 291 }( mediaWiki, jQuery ) );