( function () {
// Copied from mediawiki.requestIdleCallback
const requestIdleCallbackInternal = function ( callback ) {
setTimeout( () => {
const start = ve.now();
callback( {
didTimeout: false,
timeRemaining: function () {
// Hard code a target maximum busy time of 50 milliseconds
return Math.max( 0, 50 - ( ve.now() - start ) );
}
} );
}, 1 );
};
// eslint-disable-next-line compat/compat
const requestIdleCallback = window.requestIdleCallback ?
// Bind because it throws TypeError if context is not window
// eslint-disable-next-line compat/compat
window.requestIdleCallback.bind( window ) :
requestIdleCallbackInternal;
const EXPIRY_PREFIX = '_EXPIRY_';
/**
* Implementation of ve.init.SafeStorage
*
* Duplicate of mediawiki.storage.
*
* @class ve.init.sa.SafeStorage
* @extends ve.init.SafeStorage
*
* @constructor
* @param {Storage|undefined} store The Storage instance to wrap around
*/
ve.init.sa.SafeStorage = function ( store ) {
this.store = store;
// Purge expired items once per page session
setTimeout( () => {
this.clearExpired();
}, 2000 );
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.get = function ( key ) {
if ( this.isExpired( key ) ) {
return null;
}
try {
return this.store.getItem( key );
} catch ( e ) {}
return false;
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.set = function ( key, value, expiry ) {
if ( key.slice( 0, EXPIRY_PREFIX.length ) === EXPIRY_PREFIX ) {
throw new Error( 'Key can\'t have a prefix of ' + EXPIRY_PREFIX );
}
try {
this.store.setItem( key, value );
this.setExpires( key, expiry );
return true;
} catch ( e ) {}
return false;
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.remove = function ( key ) {
try {
this.store.removeItem( key );
this.setExpires( key );
return true;
} catch ( e ) {}
return false;
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.getObject = function ( key ) {
const json = this.get( key );
if ( json === false ) {
return false;
}
try {
return JSON.parse( json );
} catch ( e ) {}
return null;
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.setObject = function ( key, value, expiry ) {
let json;
try {
json = JSON.stringify( value );
return this.set( key, json, expiry );
} catch ( e ) {}
return false;
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.setExpires = function ( key, expiry ) {
if ( expiry ) {
try {
this.store.setItem(
EXPIRY_PREFIX + key,
Math.floor( Date.now() / 1000 ) + expiry
);
} catch ( e ) {}
} else {
try {
this.store.removeItem( EXPIRY_PREFIX + key );
} catch ( e ) {}
}
};
// Minimum amount of time (in milliseconds) for an iteration involving localStorage access.
const MIN_WORK_TIME = 3;
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.clearExpired = function () {
return this.getExpiryKeys().then( ( keys ) => $.Deferred( ( d ) => {
const iterate = ( deadline ) => {
while ( keys[ 0 ] !== undefined && deadline.timeRemaining() > MIN_WORK_TIME ) {
const key = keys.shift();
if ( this.isExpired( key ) ) {
this.remove( key );
}
}
if ( keys[ 0 ] !== undefined ) {
// Ran out of time with keys still to remove, continue later
requestIdleCallback( iterate );
} else {
return d.resolve();
}
};
requestIdleCallback( iterate );
} ) );
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.getExpiryKeys = function () {
const store = this.store;
return $.Deferred( ( d ) => {
requestIdleCallback( ( deadline ) => {
const prefixLength = EXPIRY_PREFIX.length;
const keys = [];
let length = 0;
try {
length = store.length;
} catch ( e ) {}
// Optimization: If time runs out, degrade to checking fewer keys.
// We will get another chance during a future page view. Iterate forward
// so that older keys are checked first and increase likelihood of recovering
// from key exhaustion.
//
// We don't expect to have more keys than we can handle in 50ms long-task window.
// But, we might still run out of time when other tasks run before this,
// or when the device receives UI events (especially on low-end devices).
for ( let i = 0; ( i < length && deadline.timeRemaining() > MIN_WORK_TIME ); i++ ) {
let key = null;
try {
key = store.key( i );
} catch ( e ) {}
if ( key !== null && key.slice( 0, prefixLength ) === EXPIRY_PREFIX ) {
keys.push( key.slice( prefixLength ) );
}
}
d.resolve( keys );
} );
} ).promise();
};
/**
* @inheritdoc
*/
ve.init.sa.SafeStorage.prototype.isExpired = function ( key ) {
let expiry;
try {
expiry = this.store.getItem( EXPIRY_PREFIX + key );
} catch ( e ) {
return false;
}
return !!expiry && expiry < Math.floor( Date.now() / 1000 );
};
}() );