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node_modules/fontkit/src/decorators.js
| 36 lines
| 936 B
| application/javascript
| JavascriptLexer
|
| r789 | /** | |||
| * This decorator caches the results of a getter or method such that | ||||
| * the results are lazily computed once, and then cached. | ||||
| * @private | ||||
| */ | ||||
| export function cache(target, key, descriptor) { | ||||
| if (descriptor.get) { | ||||
| let get = descriptor.get; | ||||
| descriptor.get = function() { | ||||
| let value = get.call(this); | ||||
| Object.defineProperty(this, key, { value }); | ||||
| return value; | ||||
| }; | ||||
| } else if (typeof descriptor.value === 'function') { | ||||
| let fn = descriptor.value; | ||||
| return { | ||||
| get() { | ||||
| let cache = new Map; | ||||
| function memoized(...args) { | ||||
| let key = args.length > 0 ? args[0] : 'value'; | ||||
| if (cache.has(key)) { | ||||
| return cache.get(key); | ||||
| } | ||||
| let result = fn.apply(this, args); | ||||
| cache.set(key, result); | ||||
| return result; | ||||
| }; | ||||
| Object.defineProperty(this, key, {value: memoized}); | ||||
| return memoized; | ||||
| } | ||||
| }; | ||||
| } | ||||
| } | ||||