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- 'use strict';
- let fastProto = null;
- // Creates an object with permanently fast properties in V8. See Toon Verwaest's
- // post https://medium.com/@tverwaes/setting-up-prototypes-in-v8-ec9c9491dfe2#5f62
- // for more details. Use %HasFastProperties(object) and the Node.js flag
- // --allow-natives-syntax to check whether an object has fast properties.
- function FastObject(o) {
- // A prototype object will have "fast properties" enabled once it is checked
- // against the inline property cache of a function, e.g. fastProto.property:
- // https://github.com/v8/v8/blob/6.0.122/test/mjsunit/fast-prototype.js#L48-L63
- if (fastProto !== null && typeof fastProto.property) {
- const result = fastProto;
- fastProto = FastObject.prototype = null;
- return result;
- }
- fastProto = FastObject.prototype = o == null ? Object.create(null) : o;
- return new FastObject;
- }
- // Initialize the inline property cache of FastObject
- FastObject();
- module.exports = function toFastproperties(o) {
- return FastObject(o);
- };
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