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                         return payload;
  99                 },
 100
 101                 /**
 102                  * Given CSS source, count both the total number of selectors it
 103                  * contains and the number which match some element in the current
 104                  * document.
 105                  *
 106                  * @param {string} css CSS source
 107                  * @return {Object} Selector counts
 108                  * @return {number} return.selectors Total number of selectors
 109                  * @return {number} return.matched Number of matched selectors
 110                  */
 111                 auditSelectors: function ( css ) {
 112                         var selectors = { total: 0, matched: 0 },
 113                                 style = document.createElement( 'style' );
 114
 115                         style.textContent = css;
 116                         document.body.appendChild( style );
 117                         $.each( style.sheet.cssRules, function ( index, rule ) {
 118                                 selectors.total++;
 119                                 // document.querySelector() on prefixed pseudo-elements can throw exceptions
 120                                 // in Firefox and Safari. Ignore these exceptions.
 121                                 // https://bugs.webkit.org/show_bug.cgi?id=149160
 122                                 // https://bugzilla.mozilla.org/show_bug.cgi?id=1204880
 123                                 try {
 124                                         if ( document.querySelector( rule.selectorText ) !== null ) {
 125                                                 selectors.matched++;
 126                                         }
 127                                 } catch ( e ) {}
 128                         } );
 129                         document.body.removeChild( style );
 130                         return selectors;
 131                 },
 132
 133                 /**
 134                  * Get a list of all loaded ResourceLoader modules.
 135                  *
 136                  * @return {Array} List of module names
 137                  */
 138                 getLoadedModules: function () {
 139                         return $.grep( mw.loader.getModuleNames(), function ( module ) {
 140                                 return mw.loader.getState( module ) === 'ready';
 141                         } );
 142                 },
 143
 144                 /**
 145                  * Print tabular data to the console, using console.table, console.log,
 146                  * or mw.log (in declining order of preference).
 147                  *
 148                  * @param {Array} data Tabular data represented as an array of objects
 149                  *  with common properties.
 150                  */
 151                 dumpTable: function ( data ) {
 152                         try {
 153                                 // Bartosz made me put this here.
 154                                 if ( window.opera ) { throw window.opera; }
 155                                 // Use Function.prototype#call to force an exception on Firefox,
 156                                 // which doesn't define console#table but doesn't complain if you
 157                                 // try to invoke it.
 158                                 console.table.call( console, data );
 159                                 return;
 160                         } catch ( e ) {}
 161                         try {
 162                                 console.log( JSON.stringify( data, null, 2 ) );
 163                                 return;
 164                         } catch ( e ) {}
 165                         mw.log( data );
 166                 },
 167
 168                 /**
 169                  * Generate and print one more reports. When invoked with no arguments,
 170                  * print all reports.
 171                  *
 172                  * @param {...string} [reports] Report names to run, or unset to print
 173                  *  all available reports.
 174                  */
 175                 runReports: function () {
 176                         var reports = arguments.length > 0 ?
 177                                 Array.prototype.slice.call( arguments ) :
 178                                 $.map( inspect.reports, function ( v, k ) { return k; } );
 179
 180                         $.each( reports, function ( index, name ) {
 181                                 inspect.dumpTable( inspect.reports[ name ]() );
 182                         } );
 183                 },
 184
 185                 /**
 186                  * @class mw.inspect.reports
 187                  * @singleton
 188                  */
 189                 reports: {
 190                         /**
 191                          * Generate a breakdown of all loaded modules and their size in
 192                          * kilobytes. Modules are ordered from largest to smallest.
 193                          *
 194                          * @return {Object[]} Size reports
 195                          */
 196                         size: function () {
 197                                 // Map each module to a descriptor object.
 198                                 var modules = $.map( inspect.getLoadedModules(), function ( module ) {
 199                                         return {
 200                                                 name: module,
 201                                                 size: inspect.getModuleSize( module )
 202                                         };
 203                                 } );
 204
 205                                 // Sort module descriptors by size, largest first.
 206                                 sortByProperty( modules, 'size', true );
 207
 208                                 // Convert size to human-readable string.
 209                                 $.each( modules, function ( i, module ) {
 210                                         module.sizeInBytes = module.size;
 211                                         module.size = humanSize( module.size );
 212                                 } );
 213
 214                                 return modules;
 215                         },
 216
 217                         /**
 218                          * For each module with styles, count the number of selectors, and
 219                          * count how many match against some element currently in the DOM.
 220                          *
 221                          * @return {Object[]} CSS reports
 222                          */
 223                         css: function () {
 224                                 var modules = [];
 225
 226                                 $.each( inspect.getLoadedModules(), function ( index, name ) {
 227                                         var css, stats, module = mw.loader.moduleRegistry[ name ];
 228
 229                                         try {
 230                                                 css = module.style.css.join();
 231                                         } catch ( e ) { return; } // skip
 232
 233                                         stats = inspect.auditSelectors( css );
 234                                         modules.push( {
 235                                                 module: name,
 236                                                 allSelectors: stats.total,
 237                                                 matchedSelectors: stats.matched,
 238                                                 percentMatched: stats.total !== 0 ?
 239                                                         ( stats.matched / stats.total * 100 ).toFixed( 2 ) + '%' : null
 240                                         } );
 241                                 } );
 242                                 sortByProperty( modules, 'allSelectors', true );
 243                                 return modules;
 244                         },
 245
 246                         /**
 247                          * Report stats on mw.loader.store: the number of localStorage
 248                          * cache hits and misses, the number of items purged from the
 249                          * cache, and the total size of the module blob in localStorage.
 250                          *
 251                          * @return {Object[]} Store stats
 252                          */
 253                         store: function () {
 254                                 var raw, stats = { enabled: mw.loader.store.enabled };
 255                                 if ( stats.enabled ) {
 256                                         $.extend( stats, mw.loader.store.stats );
 257                                         try {
 258                                                 raw = localStorage.getItem( mw.loader.store.getStoreKey() );
 259                                                 stats.totalSizeInBytes = $.byteLength( raw );
 260                                                 stats.totalSize = humanSize( $.byteLength( raw ) );
 261                                         } catch ( e ) {}
 262                                 }
 263                                 return [ stats ];
 264                         }
 265                 },
 266
 267                 /**
 268                  * Perform a string search across the JavaScript and CSS source code
 269                  * of all loaded modules and return an array of the names of the
 270                  * modules that matched.
 271                  *
 272                  * @param {string|RegExp} pattern String or regexp to match.
 273                  * @return {Array} Array of the names of modules that matched.
 274                  */
 275                 grep: function ( pattern ) {
 276                         if ( typeof pattern.test !== 'function' ) {
 277                                 pattern = new RegExp( mw.RegExp.escape( pattern ), 'g' );
 278                         }
 279
 280                         return $.grep( inspect.getLoadedModules(), function ( moduleName ) {
 281                                 var module = mw.loader.moduleRegistry[ moduleName ];
 282
 283                                 // Grep module's JavaScript
 284                                 if ( $.isFunction( module.script ) && pattern.test( module.script.toString() ) ) {
 285                                         return true;
 286                                 }
 287
 288                                 // Grep module's CSS
 289                                 if (
 290                                         $.isPlainObject( module.style ) && $.isArray( module.style.css ) &&
 291                                         pattern.test( module.style.css.join( '' ) )
 292                                 ) {
 293                                         // Module's CSS source matches
 294                                         return true;
 295                                 }
 296
 297                                 return false;
 298                         } );
 299                 }
 300         };
 301
 302         if ( mw.config.get( 'debug' ) ) {
 303                 mw.log( 'mw.inspect: reports are not available in debug mode.' );
 304         }
 305
 306         mw.inspect = inspect;
 307
 308 }( mediaWiki, jQuery ) );