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
   8 /* eslint-disable no-console */
   9
  10 ( function ( mw, $ ) {
  11
  12         var inspect,
  13                 hasOwn = Object.prototype.hasOwnProperty;
  14
  15         function sortByProperty( array, prop, descending ) {
  16                 var order = descending ? -1 : 1;
  17                 return array.sort( function ( a, b ) {
  18                         return a[ prop ] > b[ prop ] ? order : a[ prop ] < b[ prop ] ? -order : 0;
  19                 } );
  20         }
  21
  22         function humanSize( bytes ) {
  23                 var i,
  24                         units = [ '', ' KiB', ' MiB', ' GiB', ' TiB', ' PiB' ];
  25
  26                 if ( !$.isNumeric( bytes ) || bytes === 0 ) { return bytes; }
  27
  28                 for ( i = 0; bytes >= 1024; bytes /= 1024 ) { i++; }
  29                 // Maintain one decimal for kB and above, but don't
  30                 // add ".0" for bytes.
  31                 return bytes.toFixed( i > 0 ? 1 : 0 ) + units[ i ];
  32         }
  33
  34         /**
  35          * @class mw.inspect
  36          * @singleton
  37          */
  38         inspect = {
  39
  40                 /**
  41                  * Return a map of all dependency relationships between loaded modules.
  42                  *
  43                  * @return {Object} Maps module names to objects. Each sub-object has
  44                  *  two properties, 'requires' and 'requiredBy'.
  45                  */
  46                 getDependencyGraph: function () {
  47                         var modules = inspect.getLoadedModules(),
  48                                 graph = {};
  49
  50                         $.each( modules, function ( moduleIndex, moduleName ) {
  51                                 var dependencies = mw.loader.moduleRegistry[ moduleName ].dependencies || [];
  52
  53                                 if ( !hasOwn.call( graph, moduleName ) ) {
  54                                         graph[ moduleName ] = { requiredBy: [] };
  55                                 }
  56                                 graph[ moduleName ].requires = dependencies;
  57
  58                                 $.each( dependencies, function ( depIndex, depName ) {
  59                                         if ( !hasOwn.call( graph, depName ) ) {
  60                                                 graph[ depName ] = { requiredBy: [] };
  61                                         }
  62                                         graph[ depName ].requiredBy.push( moduleName );
  63                                 } );
  64                         } );
  65                         return graph;
  66                 },
  67
  68                 /**
  69                  * Calculate the byte size of a ResourceLoader module.
  70                  *
  71                  * @param {string} moduleName The name of the module
  72                  * @return {number|null} Module size in bytes or null
  73                  */
  74                 getModuleSize: function ( moduleName ) {
  75                         var module = mw.loader.moduleRegistry[ moduleName ],
  76                                 payload = 0;
  77
  78                         if ( mw.loader.getState( moduleName ) !== 'ready' ) {
  79                                 return null;
  80                         }
  81
  82                         if ( !module.style && !module.script ) {
  83                                 return null;
  84                         }
  85
  86                         // Tally CSS
  87                         if ( module.style && $.isArray( module.style.css ) ) {
  88                                 $.each( module.style.css, function ( i, stylesheet ) {
  89                                         payload += $.byteLength( stylesheet );
  90                                 } );
  91                         }
  92
  93                         // Tally JavaScript
  94                         if ( $.isFunction( module.script ) ) {
  95                                 payload += $.byteLength( module.script.toString() );
  96                         }
  97
  98                         // Tally templates and messages. Calculate their JSON size so that keys
  99                         // are included in the module size - in the case of messages, keys can be
 100                         // longer than values - and so that empty objects are also included.
 101                         $.each( [ module.templates, module.messages ], function ( i, object ) {
 102                                 if ( object ) {
 103                                         payload += $.byteLength( JSON.stringify( object ) );
 104                                 }
 105                         } );
 106
 107                         return payload;
 108                 },
 109
 110                 /**
 111                  * Given CSS source, count both the total number of selectors it
 112                  * contains and the number which match some element in the current
 113                  * document.
 114                  *
 115                  * @param {string} css CSS source
 116                  * @return {Object} Selector counts
 117                  * @return {number} return.selectors Total number of selectors
 118                  * @return {number} return.matched Number of matched selectors
 119                  */
 120                 auditSelectors: function ( css ) {
 121                         var selectors = { total: 0, matched: 0 },
 122                                 style = document.createElement( 'style' );
 123
 124                         style.textContent = css;
 125                         document.body.appendChild( style );
 126                         $.each( style.sheet.cssRules, function ( index, rule ) {
 127                                 selectors.total++;
 128                                 // document.querySelector() on prefixed pseudo-elements can throw exceptions
 129                                 // in Firefox and Safari. Ignore these exceptions.
 130                                 // https://bugs.webkit.org/show_bug.cgi?id=149160
 131                                 // https://bugzilla.mozilla.org/show_bug.cgi?id=1204880
 132                                 try {
 133                                         if ( document.querySelector( rule.selectorText ) !== null ) {
 134                                                 selectors.matched++;
 135                                         }
 136                                 } catch ( e ) {}
 137                         } );
 138                         document.body.removeChild( style );
 139                         return selectors;
 140                 },
 141
 142                 /**
 143                  * Get a list of all loaded ResourceLoader modules.
 144                  *
 145                  * @return {Array} List of module names
 146                  */
 147                 getLoadedModules: function () {
 148                         return $.grep( mw.loader.getModuleNames(), function ( module ) {
 149                                 return mw.loader.getState( module ) === 'ready';
 150                         } );
 151                 },
 152
 153                 /**
 154                  * Print tabular data to the console, using console.table, console.log,
 155                  * or mw.log (in declining order of preference).
 156                  *
 157                  * @param {Array} data Tabular data represented as an array of objects
 158                  *  with common properties.
 159                  */
 160                 dumpTable: function ( data ) {
 161                         try {
 162                                 // Bartosz made me put this here.
 163                                 if ( window.opera ) { throw window.opera; }
 164                                 // Use Function.prototype#call to force an exception on Firefox,
 165                                 // which doesn't define console#table but doesn't complain if you
 166                                 // try to invoke it.
 167                                 console.table.call( console, data );
 168                                 return;
 169                         } catch ( e ) {}
 170                         try {
 171                                 console.log( JSON.stringify( data, null, 2 ) );
 172                                 return;
 173                         } catch ( e ) {}
 174                         mw.log( data );
 175                 },
 176
 177                 /**
 178                  * Generate and print one more reports. When invoked with no arguments,
 179                  * print all reports.
 180                  *
 181                  * @param {...string} [reports] Report names to run, or unset to print
 182                  *  all available reports.
 183                  */
 184                 runReports: function () {
 185                         var reports = arguments.length > 0 ?
 186                                 Array.prototype.slice.call( arguments ) :
 187                                 $.map( inspect.reports, function ( v, k ) { return k; } );
 188
 189                         $.each( reports, function ( index, name ) {
 190                                 inspect.dumpTable( inspect.reports[ name ]() );
 191                         } );
 192                 },
 193
 194                 /**
 195                  * @class mw.inspect.reports
 196                  * @singleton
 197                  */
 198                 reports: {
 199                         /**
 200                          * Generate a breakdown of all loaded modules and their size in
 201                          * kilobytes. Modules are ordered from largest to smallest.
 202                          *
 203                          * @return {Object[]} Size reports
 204                          */
 205                         size: function () {
 206                                 // Map each module to a descriptor object.
 207                                 var modules = $.map( inspect.getLoadedModules(), function ( module ) {
 208                                         return {
 209                                                 name: module,
 210                                                 size: inspect.getModuleSize( module )
 211                                         };
 212                                 } );
 213
 214                                 // Sort module descriptors by size, largest first.
 215                                 sortByProperty( modules, 'size', true );
 216
 217                                 // Convert size to human-readable string.
 218                                 $.each( modules, function ( i, module ) {
 219                                         module.sizeInBytes = module.size;
 220                                         module.size = humanSize( module.size );
 221                                 } );
 222
 223                                 return modules;
 224                         },
 225
 226                         /**
 227                          * For each module with styles, count the number of selectors, and
 228                          * count how many match against some element currently in the DOM.
 229                          *
 230                          * @return {Object[]} CSS reports
 231                          */
 232                         css: function () {
 233                                 var modules = [];
 234
 235                                 $.each( inspect.getLoadedModules(), function ( index, name ) {
 236                                         var css, stats, module = mw.loader.moduleRegistry[ name ];
 237
 238                                         try {
 239                                                 css = module.style.css.join();
 240                                         } catch ( e ) { return; } // skip
 241
 242                                         stats = inspect.auditSelectors( css );
 243                                         modules.push( {
 244                                                 module: name,
 245                                                 allSelectors: stats.total,
 246                                                 matchedSelectors: stats.matched,
 247                                                 percentMatched: stats.total !== 0 ?
 248                                                         ( stats.matched / stats.total * 100 ).toFixed( 2 ) + '%' : null
 249                                         } );
 250                                 } );
 251                                 sortByProperty( modules, 'allSelectors', true );
 252                                 return modules;
 253                         },
 254
 255                         /**
 256                          * Report stats on mw.loader.store: the number of localStorage
 257                          * cache hits and misses, the number of items purged from the
 258                          * cache, and the total size of the module blob in localStorage.
 259                          *
 260                          * @return {Object[]} Store stats
 261                          */
 262                         store: function () {
 263                                 var raw, stats = { enabled: mw.loader.store.enabled };
 264                                 if ( stats.enabled ) {
 265                                         $.extend( stats, mw.loader.store.stats );
 266                                         try {
 267                                                 raw = localStorage.getItem( mw.loader.store.getStoreKey() );
 268                                                 stats.totalSizeInBytes = $.byteLength( raw );
 269                                                 stats.totalSize = humanSize( $.byteLength( raw ) );
 270                                         } catch ( e ) {}
 271                                 }
 272                                 return [ stats ];
 273                         }
 274                 },
 275
 276                 /**
 277                  * Perform a string search across the JavaScript and CSS source code
 278                  * of all loaded modules and return an array of the names of the
 279                  * modules that matched.
 280                  *
 281                  * @param {string|RegExp} pattern String or regexp to match.
 282                  * @return {Array} Array of the names of modules that matched.
 283                  */
 284                 grep: function ( pattern ) {
 285                         if ( typeof pattern.test !== 'function' ) {
 286                                 pattern = new RegExp( mw.RegExp.escape( pattern ), 'g' );
 287                         }
 288
 289                         return $.grep( inspect.getLoadedModules(), function ( moduleName ) {
 290                                 var module = mw.loader.moduleRegistry[ moduleName ];
 291
 292                                 // Grep module's JavaScript
 293                                 if ( $.isFunction( module.script ) && pattern.test( module.script.toString() ) ) {
 294                                         return true;
 295                                 }
 296
 297                                 // Grep module's CSS
 298                                 if (
 299                                         $.isPlainObject( module.style ) && $.isArray( module.style.css ) &&
 300                                         pattern.test( module.style.css.join( '' ) )
 301                                 ) {
 302                                         // Module's CSS source matches
 303                                         return true;
 304                                 }
 305
 306                                 return false;
 307                         } );
 308                 }
 309         };
 310
 311         if ( mw.config.get( 'debug' ) ) {
 312                 mw.log( 'mw.inspect: reports are not available in debug mode.' );
 313         }
 314
 315         mw.inspect = inspect;
 316
 317 }( mediaWiki, jQuery ) );