/**
* Base library for MediaWiki.
*
- * Exposed globally as `mediaWiki` with `mw` as shortcut.
+ * Exposed globally as `mw`, with `mediaWiki` as alias.
*
* @class mw
* @alternateClassName mediaWiki
'use strict';
var mw, StringSet, log,
- hasOwn = Object.prototype.hasOwnProperty,
trackQueue = [];
/**
function defineFallbacks() {
// <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set>
- StringSet = window.Set || ( function () {
- /**
- * @private
- * @class
- */
- function StringSet() {
- this.set = Object.create( null );
- }
- StringSet.prototype.add = function ( value ) {
- this.set[ value ] = true;
+ /**
+ * @private
+ * @class
+ */
+ StringSet = window.Set || function StringSet() {
+ var set = Object.create( null );
+ this.add = function ( value ) {
+ set[ value ] = true;
};
- StringSet.prototype.has = function ( value ) {
- return value in this.set;
+ this.has = function ( value ) {
+ return value in set;
};
- return StringSet;
- }() );
+ };
}
/**
defineFallbacks();
- /* eslint-disable no-console */
log = ( function () {
/**
* Write a verbose message to the browser's console in debug mode.
*
* @param {...string} msg Messages to output to console
*/
- log.warn = console && console.warn && Function.prototype.bind ?
+ log.warn = console && console.warn ?
Function.prototype.bind.call( console.warn, console ) :
function () {};
* @since 1.26
* @param {...Mixed} msg Messages to output to console
*/
- log.error = console && console.error && Function.prototype.bind ?
+ log.error = console && console.error ?
Function.prototype.bind.call( console.error, console ) :
function () {};
* @param {string} [logName=key] Optional custom name for the feature.
* This is used instead of `key` in the message and `mw.deprecate` tracking.
*/
- log.deprecate = !Object.defineProperty ? function ( obj, key, val ) {
- obj[ key ] = val;
- } : function ( obj, key, val, msg, logName ) {
- var logged = new StringSet();
- logName = logName || key;
- msg = 'Use of "' + logName + '" is deprecated.' + ( msg ? ( ' ' + msg ) : '' );
- function uniqueTrace() {
- var trace = new Error().stack;
- if ( logged.has( trace ) ) {
- return false;
+ log.deprecate = function ( obj, key, val, msg, logName ) {
+ var stacks;
+ function maybeLog() {
+ var name,
+ trace = new Error().stack;
+ if ( !stacks ) {
+ stacks = new StringSet();
+ }
+ if ( !stacks.has( trace ) ) {
+ stacks.add( trace );
+ name = logName || key;
+ mw.track( 'mw.deprecate', name );
+ mw.log.warn(
+ 'Use of "' + name + '" is deprecated.' + ( msg ? ( ' ' + msg ) : '' )
+ );
}
- logged.add( trace );
- return true;
}
// Support: Safari 5.0
// Throws "not supported on DOM Objects" for Node or Element objects (incl. document)
configurable: true,
enumerable: true,
get: function () {
- if ( uniqueTrace() ) {
- mw.track( 'mw.deprecate', logName );
- mw.log.warn( msg );
- }
+ maybeLog();
return val;
},
set: function ( newVal ) {
- if ( uniqueTrace() ) {
- mw.track( 'mw.deprecate', logName );
- mw.log.warn( msg );
- }
+ maybeLog();
val = newVal;
}
} );
return log;
}() );
- /* eslint-enable no-console */
/**
* @class mw
/**
* Get the current time, measured in milliseconds since January 1, 1970 (UTC).
*
- * On browsers that implement the Navigation Timing API, this function will produce floating-point
- * values with microsecond precision that are guaranteed to be monotonic. On all other browsers,
- * it will fall back to using `Date`.
+ * On browsers that implement the Navigation Timing API, this function will produce
+ * floating-point values with microsecond precision that are guaranteed to be monotonic.
+ * On all other browsers, it will fall back to using `Date`.
*
* @return {number} Current time
*/
- now: ( function () {
+ now: function () {
+ // Optimisation: Define the shortcut on first call, not at module definition.
var perf = window.performance,
navStart = perf && perf.timing && perf.timing.navigationStart;
- return navStart && typeof perf.now === 'function' ?
+
+ // Define the relevant shortcut
+ mw.now = navStart && typeof perf.now === 'function' ?
function () { return navStart + perf.now(); } :
- function () { return Date.now(); };
- }() ),
+ Date.now;
+
+ return mw.now();
+ },
/**
* List of all analytic events emitted so far.
* - resolve: failed to sort dependencies for a module in mw.loader.load
* - store-eval: could not evaluate module code cached in localStorage
* - store-localstorage-init: localStorage or JSON parse error in mw.loader.store.init
- * - store-localstorage-json: JSON conversion error in mw.loader.store.set
- * - store-localstorage-update: localStorage or JSON conversion error in mw.loader.store.update
+ * - store-localstorage-json: JSON conversion error in mw.loader.store
+ * - store-localstorage-update: localStorage conversion error in mw.loader.store.
*/
/**
* The contents are then stashed in the registry via mw.loader#implement.
* - `loaded`:
* The module has been loaded from the server and stashed via mw.loader#implement.
- * If the module has no more dependencies in-flight, the module will be executed
- * immediately. Otherwise execution is deferred, controlled via #handlePending.
+ * Once the module has no more dependencies in-flight, the module will be executed,
+ * controlled via #requestPropagation and #doPropagation.
* - `executing`:
* The module is being executed.
* - `ready`:
* @property
* @private
*/
- var registry = {},
+ var registry = Object.create( null ),
// Mapping of sources, keyed by source-id, values are strings.
//
// Format:
// 'sourceId': 'http://example.org/w/load.php'
// }
//
- sources = {},
+ sources = Object.create( null ),
// For queueModuleScript()
handlingPendingRequests = false,
/**
* List of callback jobs waiting for modules to be ready.
*
- * Jobs are created by #enqueue() and run by #handlePending().
- *
+ * Jobs are created by #enqueue() and run by #doPropagation().
* Typically when a job is created for a module, the job's dependencies contain
* both the required module and all its recursive dependencies.
*
*/
jobs = [],
+ // For #requestPropagation() and #doPropagation()
+ willPropagate = false,
+ errorModules = [],
+
/**
* @private
* @property {Array} baseModules
}
/**
- * A module has entered state 'ready', 'error', or 'missing'. Automatically update
- * pending jobs and modules that depend upon this module. If the given module failed,
- * propagate the 'error' state up the dependency tree. Otherwise, go ahead and execute
- * all jobs/modules now having their dependencies satisfied.
+ * Handle propagation of module state changes and reactions to them.
*
- * Jobs that depend on a failed module, will have their error callback ran (if any).
+ * - When a module reaches a failure state, this should be propagated to
+ * modules that depend on the failed module.
+ * - When a module reaches a final state, pending job callbacks for the
+ * module from mw.loader.using() should be called.
+ * - When a module reaches the 'ready' state from #execute(), consider
+ * executing dependant modules now having their dependencies satisfied.
+ * - When a module reaches the 'loaded' state from mw.loader.implement,
+ * consider executing it, if it has no unsatisfied dependencies.
*
* @private
- * @param {string} module Name of module that entered one of the states 'ready', 'error', or 'missing'.
*/
- function handlePending( module ) {
- var j, job, hasErrors, m, stateChange, fromBaseModule;
-
- if ( registry[ module ].state === 'error' || registry[ module ].state === 'missing' ) {
- fromBaseModule = baseModules.indexOf( module ) !== -1;
- // If the current module failed, mark all dependent modules also as failed.
- // Iterate until steady-state to propagate the error state upwards in the
- // dependency tree.
- do {
- stateChange = false;
- for ( m in registry ) {
- if ( registry[ m ].state !== 'error' && registry[ m ].state !== 'missing' ) {
- // Always propagate errors from base modules to regular modules (implicit dependency).
- // Between base modules or regular modules, consider direct dependencies only.
- if (
- ( fromBaseModule && baseModules.indexOf( m ) === -1 ) ||
- anyFailed( registry[ m ].dependencies )
- ) {
- registry[ m ].state = 'error';
- stateChange = true;
+ function doPropagation() {
+ var errorModule, baseModuleError, module, i, failed, job,
+ didPropagate = true;
+
+ // Keep going until the last iteration performed no actions.
+ do {
+ didPropagate = false;
+
+ // Stage 1: Propagate failures
+ while ( errorModules.length ) {
+ errorModule = errorModules.shift();
+ baseModuleError = baseModules.indexOf( errorModule ) !== -1;
+ for ( module in registry ) {
+ if ( registry[ module ].state !== 'error' && registry[ module ].state !== 'missing' ) {
+ if ( baseModuleError && baseModules.indexOf( module ) === -1 ) {
+ // Propate error from base module to all regular (non-base) modules
+ registry[ module ].state = 'error';
+ didPropagate = true;
+ } else if ( registry[ module ].dependencies.indexOf( errorModule ) !== -1 ) {
+ // Propagate error from dependency to depending module
+ registry[ module ].state = 'error';
+ // .. and propagate it further
+ errorModules.push( module );
+ didPropagate = true;
}
}
}
- } while ( stateChange );
- }
+ }
- // Execute all jobs whose dependencies are either all satisfied or contain at least one failed module.
- for ( j = 0; j < jobs.length; j++ ) {
- hasErrors = anyFailed( jobs[ j ].dependencies );
- if ( hasErrors || allReady( jobs[ j ].dependencies ) ) {
- // All dependencies satisfied, or some have errors
- job = jobs[ j ];
- jobs.splice( j, 1 );
- j -= 1;
- try {
- if ( hasErrors ) {
- if ( typeof job.error === 'function' ) {
- job.error( new Error( 'Module ' + module + ' has failed dependencies' ), [ module ] );
- }
- } else {
- if ( typeof job.ready === 'function' ) {
+ // Stage 2: Execute 'loaded' modules with no unsatisfied dependencies
+ for ( module in registry ) {
+ if ( registry[ module ].state === 'loaded' && allWithImplicitReady( module ) ) {
+ // Recursively execute all dependent modules that were already loaded
+ // (waiting for execution) and no longer have unsatisfied dependencies.
+ // Base modules may have dependencies amongst eachother to ensure correct
+ // execution order. Regular modules wait for all base modules.
+ // eslint-disable-next-line no-use-before-define
+ execute( module );
+ didPropagate = true;
+ }
+ }
+
+ // Stage 3: Invoke job callbacks that are no longer blocked
+ for ( i = 0; i < jobs.length; i++ ) {
+ job = jobs[ i ];
+ failed = anyFailed( job.dependencies );
+ if ( failed || allReady( job.dependencies ) ) {
+ jobs.splice( i, 1 );
+ i -= 1;
+ try {
+ if ( failed && job.error ) {
+ job.error( new Error( 'Module has failed dependencies' ), job.dependencies );
+ } else if ( !failed && job.ready ) {
job.ready();
}
+ } catch ( e ) {
+ // A user-defined callback raised an exception.
+ // Swallow it to protect our state machine!
+ mw.trackError( 'resourceloader.exception', {
+ exception: e,
+ source: 'load-callback'
+ } );
}
- } catch ( e ) {
- // A user-defined callback raised an exception.
- // Swallow it to protect our state machine!
- mw.trackError( 'resourceloader.exception', {
- exception: e,
- module: module,
- source: 'load-callback'
- } );
+ didPropagate = true;
}
}
+ } while ( didPropagate );
+
+ willPropagate = false;
+ }
+
+ /**
+ * Request a (debounced) call to doPropagation().
+ *
+ * @private
+ */
+ function requestPropagation() {
+ if ( willPropagate ) {
+ // Already scheduled, or, we're already in a doPropagation stack.
+ return;
}
+ willPropagate = true;
+ // Yield for two reasons:
+ // * Allow successive calls to mw.loader.implement() from the same
+ // load.php response, or from the same asyncEval() to be in the
+ // propagation batch.
+ // * Allow the browser to breathe between the reception of
+ // module source code and the execution of it.
+ //
+ // Use a high priority because the user may be waiting for interactions
+ // to start being possible. But, first provide a moment (up to 'timeout')
+ // for native input event handling (e.g. scrolling/typing/clicking).
+ mw.requestIdleCallback( doPropagation, { timeout: 1 } );
+ }
- // The current module became 'ready'.
- if ( registry[ module ].state === 'ready' ) {
- // Save it to the module store.
- mw.loader.store.set( module, registry[ module ] );
- // Recursively execute all dependent modules that were already loaded
- // (waiting for execution) and no longer have unsatisfied dependencies.
- for ( m in registry ) {
- // Base modules may have dependencies amongst eachother to ensure correct
- // execution order. Regular modules wait for all base modules.
- if ( registry[ m ].state === 'loaded' && allWithImplicitReady( m ) ) {
- // eslint-disable-next-line no-use-before-define
- execute( m );
- }
+ /**
+ * Update a module's state in the registry and make sure any neccesary
+ * propagation will occur. See #doPropagation for more about propagation.
+ * See #registry for more about how states are used.
+ *
+ * @private
+ * @param {string} module
+ * @param {string} state
+ */
+ function setAndPropagate( module, state ) {
+ registry[ module ].state = state;
+ if ( state === 'loaded' || state === 'ready' || state === 'error' || state === 'missing' ) {
+ if ( state === 'ready' ) {
+ // Queue to later be synced to the local module store.
+ mw.loader.store.add( module );
+ } else if ( state === 'error' || state === 'missing' ) {
+ errorModules.push( module );
}
+ requestPropagation();
}
}
function sortDependencies( module, resolved, unresolved ) {
var i, deps, skip;
- if ( !hasOwn.call( registry, module ) ) {
+ if ( !( module in registry ) ) {
throw new Error( 'Unknown dependency: ' + module );
}
if ( skip() ) {
registry[ module ].skipped = true;
registry[ module ].dependencies = [];
- registry[ module ].state = 'ready';
- handlePending( module );
+ setAndPropagate( module, 'ready' );
return;
}
}
function queueModuleScript( src, moduleName, callback ) {
pendingRequests.push( function () {
// Keep in sync with execute()/runScript().
- if ( moduleName !== 'jquery' && hasOwn.call( registry, moduleName ) ) {
+ if ( moduleName !== 'jquery' ) {
window.require = mw.loader.require;
window.module = registry[ moduleName ].module;
}
// Private modules must be embedded in the page. Don't bother queuing
// these as the server will deny them anyway (T101806).
if ( registry[ module ].group === 'private' ) {
- registry[ module ].state = 'error';
- handlePending( module );
+ setAndPropagate( module, 'error' );
return;
}
queue.push( module );
var key, value, media, i, urls, cssHandle, siteDeps, siteDepErr, runScript,
cssPending = 0;
- if ( !hasOwn.call( registry, module ) ) {
- throw new Error( 'Module has not been registered yet: ' + module );
- }
if ( registry[ module ].state !== 'loaded' ) {
throw new Error( 'Module in state "' + registry[ module ].state + '" may not be executed: ' + module );
}
script = registry[ module ].script;
markModuleReady = function () {
$CODE.profileScriptEnd();
- registry[ module ].state = 'ready';
- handlePending( module );
+ setAndPropagate( module, 'ready' );
};
nestedAddScript = function ( arr, callback, i ) {
// Recursively call queueModuleScript() in its own callback
} catch ( e ) {
// Use mw.track instead of mw.log because these errors are common in production mode
// (e.g. undefined variable), and mw.log is only enabled in debug mode.
- registry[ module ].state = 'error';
+ setAndPropagate( module, 'error' );
$CODE.profileScriptEnd();
mw.trackError( 'resourceloader.exception', {
- exception: e, module:
- module, source: 'module-execute'
+ exception: e,
+ module: module,
+ source: 'module-execute'
} );
- handlePending( module );
}
};
/**
* Resolve indexed dependencies.
*
- * ResourceLoader uses an optimization to save space which replaces module names in
+ * ResourceLoader uses an optimisation to save space which replaces module names in
* dependency lists with the index of that module within the array of module
* registration data if it exists. The benefit is a significant reduction in the data
* size of the startup module. This function changes those dependency lists back to
* or null if the module does not exist
*/
function getModuleKey( module ) {
- return hasOwn.call( registry, module ) ?
- ( module + '@' + registry[ module ].version ) : null;
+ return module in registry ? ( module + '@' + registry[ module ].version ) : null;
}
/**
};
}
+ /**
+ * @private
+ * @param {string} module
+ * @param {string|number} [version]
+ * @param {string[]} [dependencies]
+ * @param {string} [group]
+ * @param {string} [source]
+ * @param {string} [skip]
+ */
+ function registerOne( module, version, dependencies, group, source, skip ) {
+ if ( module in registry ) {
+ throw new Error( 'module already registered: ' + module );
+ }
+ registry[ module ] = {
+ // Exposed to execute() for mw.loader.implement() closures.
+ // Import happens via require().
+ module: {
+ exports: {}
+ },
+ version: String( version || '' ),
+ dependencies: dependencies || [],
+ group: typeof group === 'string' ? group : null,
+ source: typeof source === 'string' ? source : 'local',
+ state: 'registered',
+ skip: typeof skip === 'string' ? skip : null
+ };
+ }
+
/* Public Members */
return {
/**
/**
* Start loading of all queued module dependencies.
*
- * @protected
+ * @private
*/
work: function () {
var q, batch, implementations, sourceModules;
// Appends a list of modules from the queue to the batch
for ( q = 0; q < queue.length; q++ ) {
// Only load modules which are registered
- if ( hasOwn.call( registry, queue[ q ] ) && registry[ queue[ q ] ].state === 'registered' ) {
+ if ( queue[ q ] in registry && registry[ queue[ q ] ].state === 'registered' ) {
// Prevent duplicate entries
if ( batch.indexOf( queue[ q ] ) === -1 ) {
batch.push( queue[ q ] );
*
* The #work() method will use this information to split up requests by source.
*
- * mw.loader.addSource( 'mediawikiwiki', '//www.mediawiki.org/w/load.php' );
+ * mw.loader.addSource( { mediawikiwiki: 'https://www.mediawiki.org/w/load.php' } );
*
- * @param {string|Object} id Source ID, or object mapping ids to load urls
- * @param {string} loadUrl Url to a load.php end point
+ * @private
+ * @param {Object} ids An object mapping ids to load.php end point urls
* @throws {Error} If source id is already registered
*/
- addSource: function ( id, loadUrl ) {
- var source;
- // Allow multiple additions
- if ( typeof id === 'object' ) {
- for ( source in id ) {
- mw.loader.addSource( source, id[ source ] );
+ addSource: function ( ids ) {
+ var id;
+ for ( id in ids ) {
+ if ( id in sources ) {
+ throw new Error( 'source already registered: ' + id );
}
- return;
- }
-
- if ( hasOwn.call( sources, id ) ) {
- throw new Error( 'source already registered: ' + id );
+ sources[ id ] = ids[ id ];
}
-
- sources[ id ] = loadUrl;
},
/**
* Register a module, letting the system know about it and its properties.
*
- * The startup modules contain calls to this method.
+ * The startup module calls this method.
*
* When using multiple module registration by passing an array, dependencies that
* are specified as references to modules within the array will be resolved before
* the modules are registered.
*
- * @param {string|Array} module Module name or array of arrays, each containing
+ * @param {string|Array} modules Module name or array of arrays, each containing
* a list of arguments compatible with this method
- * @param {string|number} version Module version hash (falls backs to empty string)
+ * @param {string|number} [version] Module version hash (falls backs to empty string)
* Can also be a number (timestamp) for compatibility with MediaWiki 1.25 and earlier.
* @param {string[]} [dependencies] Array of module names on which this module depends.
* @param {string} [group=null] Group which the module is in
* @param {string} [source='local'] Name of the source
* @param {string} [skip=null] Script body of the skip function
*/
- register: function ( module, version, dependencies, group, source, skip ) {
+ register: function ( modules ) {
var i;
- // Allow multiple registration
- if ( typeof module === 'object' ) {
- resolveIndexedDependencies( module );
- for ( i = 0; i < module.length; i++ ) {
- // module is an array of module names
- if ( typeof module[ i ] === 'string' ) {
- mw.loader.register( module[ i ] );
- // module is an array of arrays
- } else if ( typeof module[ i ] === 'object' ) {
- mw.loader.register.apply( mw.loader, module[ i ] );
- }
+ if ( typeof modules === 'object' ) {
+ resolveIndexedDependencies( modules );
+ // Optimisation: Up to 55% faster.
+ // Typically called only once, and with a batch.
+ // See <https://gist.github.com/Krinkle/f06fdb3de62824c6c16f02a0e6ce0e66>
+ // Benchmarks taught us that the code for adding an object to `registry`
+ // should actually be inline, or in a simple function that does no
+ // arguments manipulation, and isn't also the caller itself.
+ // JS semantics make it hard to optimise recursion to a different
+ // signature of itself.
+ for ( i = 0; i < modules.length; i++ ) {
+ registerOne.apply( null, modules[ i ] );
}
- return;
- }
- if ( hasOwn.call( registry, module ) ) {
- throw new Error( 'module already registered: ' + module );
+ } else {
+ registerOne.apply( null, arguments );
}
- // List the module as registered
- registry[ module ] = {
- // Exposed to execute() for mw.loader.implement() closures.
- // Import happens via require().
- module: {
- exports: {}
- },
- version: String( version || '' ),
- dependencies: dependencies || [],
- group: typeof group === 'string' ? group : null,
- source: typeof source === 'string' ? source : 'local',
- state: 'registered',
- skip: typeof skip === 'string' ? skip : null
- };
},
/**
* The reason css strings are not concatenated anymore is T33676. We now check
* whether it's safe to extend the stylesheet.
*
- * @protected
+ * @private
* @param {Object} [messages] List of key/value pairs to be added to mw#messages.
* @param {Object} [templates] List of key/value pairs to be added to mw#templates.
*/
name = split.name,
version = split.version;
// Automatically register module
- if ( !hasOwn.call( registry, name ) ) {
+ if ( !( name in registry ) ) {
mw.loader.register( name );
}
// Check for duplicate implementation
- if ( hasOwn.call( registry, name ) && registry[ name ].script !== undefined ) {
+ if ( registry[ name ].script !== undefined ) {
throw new Error( 'module already implemented: ' + name );
}
if ( version ) {
registry[ name ].templates = templates || null;
// The module may already have been marked as erroneous
if ( registry[ name ].state !== 'error' && registry[ name ].state !== 'missing' ) {
- registry[ name ].state = 'loaded';
- if ( allWithImplicitReady( name ) ) {
- execute( name );
- }
+ setAndPropagate( name, 'loaded' );
}
},
/**
* Change the state of one or more modules.
*
- * @param {Object} modules Object of module name/state pairs
+ * @param {Object} states Object of module name/state pairs
*/
- state: function ( modules ) {
+ state: function ( states ) {
var module, state;
- for ( module in modules ) {
- state = modules[ module ];
- if ( !hasOwn.call( registry, module ) ) {
+ for ( module in states ) {
+ state = states[ module ];
+ if ( !( module in registry ) ) {
mw.loader.register( module );
}
- registry[ module ].state = state;
- if ( state === 'ready' || state === 'error' || state === 'missing' ) {
- // Make sure pending modules depending on this one get executed if their
- // dependencies are now fulfilled!
- handlePending( module );
- }
+ setAndPropagate( module, state );
}
},
* in the registry.
*/
getVersion: function ( module ) {
- return hasOwn.call( registry, module ) ? registry[ module ].version : null;
+ return module in registry ? registry[ module ].version : null;
},
/**
* in the registry.
*/
getState: function ( module ) {
- return hasOwn.call( registry, module ) ? registry[ module ].state : null;
+ return module in registry ? registry[ module ].state : null;
},
/**
// to module implementations.
items: {},
+ // Names of modules to be stored during the next update.
+ // See add() and update().
+ queue: [],
+
// Cache hit stats
stats: { hits: 0, misses: 0, expired: 0, failed: 0 },
// Disabled because localStorage quotas are tight and (in Firefox's case)
// shared by multiple origins.
// See T66721, and <https://bugzilla.mozilla.org/show_bug.cgi?id=1064466>.
- /Firefox|Opera/.test( navigator.userAgent ) ||
+ /Firefox/.test( navigator.userAgent ) ||
// Disabled by configuration.
!mw.config.get( 'wgResourceLoaderStorageEnabled' )
},
/**
- * Stringify a module and queue it for storage.
+ * Queue the name of a module that the next update should consider storing.
*
+ * @since 1.32
* @param {string} module Module name
- * @param {Object} descriptor The module's descriptor as set in the registry
*/
- set: function ( module, descriptor ) {
- var args, key, src;
-
+ add: function ( module ) {
if ( !this.enabled ) {
return;
}
+ this.queue.push( module );
+ this.requestUpdate();
+ },
+
+ /**
+ * Add the contents of the named module to the in-memory store.
+ *
+ * This method does not guarantee that the module will be stored.
+ * Inspection of the module's meta data and size will ultimately decide that.
+ *
+ * This method is considered internal to mw.loader.store and must only
+ * be called if the store is enabled.
+ *
+ * @private
+ * @param {string} module Module name
+ */
+ set: function ( module ) {
+ var key, args, src,
+ descriptor = mw.loader.moduleRegistry[ module ];
key = getModuleKey( module );
// Already stored a copy of this exact version
key in this.items ||
// Module failed to load
+ !descriptor ||
descriptor.state !== 'ready' ||
// Unversioned, private, or site-/user-specific
!descriptor.version ||
return;
}
this.items[ key ] = src;
- this.update();
},
/**
},
/**
- * Sync in-memory store back to localStorage.
+ * Request a sync of the in-memory store back to persisted localStorage.
+ *
+ * This function debounces updates. The debouncing logic should account
+ * for the following factors:
+ *
+ * - Writing to localStorage is an expensive operation that must not happen
+ * during the critical path of initialising and executing module code.
+ * Instead, it should happen at a later time after modules have been given
+ * time and priority to do their thing first.
*
- * This function debounces updates. When called with a flush already pending, the
- * scheduled flush is postponed. The call to localStorage.setItem will be keep
- * being deferred until the page is quiescent for 2 seconds.
+ * - This method is called from mw.loader.store.add(), which will be called
+ * hundreds of times on a typical page, including within the same call-stack
+ * and eventloop-tick. This is because responses from load.php happen in
+ * batches. As such, we want to allow all modules from the same load.php
+ * response to be written to disk with a single flush, not many.
*
- * Because localStorage is shared by all pages from the same origin, if multiple
- * pages are loaded with different module sets, the possibility exists that
- * modules saved by one page will be clobbered by another. The only impact of this
- * is minor (merely a less efficient cache use) and the problem would be corrected
- * by subsequent page views.
+ * - Repeatedly deleting and creating timers is non-trivial.
*
+ * - localStorage is shared by all pages from the same origin, if multiple
+ * pages are loaded with different module sets, the possibility exists that
+ * modules saved by one page will be clobbered by another. The impact of
+ * this is minor, it merely causes a less efficient cache use, and the
+ * problem would be corrected by subsequent page views.
+ *
+ * This method is considered internal to mw.loader.store and must only
+ * be called if the store is enabled.
+ *
+ * @private
* @method
*/
- update: ( function () {
- var timer, hasPendingWrites = false;
+ requestUpdate: ( function () {
+ var hasPendingWrites = false;
function flushWrites() {
var data, key;
- if ( !mw.loader.store.enabled ) {
- return;
- }
+ // Remove anything from the in-memory store that came from previous page
+ // loads that no longer corresponds with current module names and versions.
mw.loader.store.prune();
+ // Process queued module names, serialise their contents to the in-memory store.
+ while ( mw.loader.store.queue.length ) {
+ mw.loader.store.set( mw.loader.store.queue.shift() );
+ }
+
key = mw.loader.store.getStoreKey();
try {
// Replacing the content of the module store might fail if the new
} );
}
+ // Let the next call to requestUpdate() create a new timer.
hasPendingWrites = false;
}
- function request() {
- // If another mw.loader.store.set()/update() call happens in the narrow
- // time window between requestIdleCallback() and flushWrites firing, ignore it.
- // It'll be saved by the already-scheduled flush.
- if ( !hasPendingWrites ) {
- hasPendingWrites = true;
- mw.requestIdleCallback( flushWrites );
- }
+ function onTimeout() {
+ // Defer the actual write via requestIdleCallback
+ mw.requestIdleCallback( flushWrites );
}
return function () {
- // Cancel the previous timer (if it hasn't fired yet)
- clearTimeout( timer );
- timer = setTimeout( request, 2000 );
+ // On the first call to requestUpdate(), create a timer that
+ // waits at least two seconds, then calls onTimeout.
+ // The main purpose is to allow the current batch of load.php
+ // responses to complete before we do anything. This batch can
+ // trigger many hundreds of calls to requestUpdate().
+ if ( !hasPendingWrites ) {
+ hasPendingWrites = true;
+ setTimeout( onTimeout, 2000 );
+ }
};
}() )
}