39 lines
689 B
JavaScript
39 lines
689 B
JavaScript
/**
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @flow strict
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* @format
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*/
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const registry: {[key: string]: number, ...} = {};
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const register = (id: string) => {
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if (registry[id]) {
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registry[id]++;
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} else {
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registry[id] = 1;
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}
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};
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const unregister = (id: string) => {
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if (registry[id]) {
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registry[id]--;
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if (registry[id] <= 0) {
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delete registry[id];
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}
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}
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};
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const has = (id: string): number | boolean => {
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return registry[id] && registry[id] > 0;
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};
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module.exports = {
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register,
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unregister,
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has,
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};
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