fix: race condition in declaration-data.js
parent
9af4c720f0
commit
5ce54e8e10
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@ -25,6 +25,7 @@ export class DeclarationDataCenter {
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* Used to implement the singleton, in case we need to fetch data mutiple times in the same page.
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* Used to implement the singleton, in case we need to fetch data mutiple times in the same page.
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*/
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*/
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static singleton = null;
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static singleton = null;
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static requestSingleton = null;
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/**
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/**
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* Construct a DeclarationDataCenter with given data.
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* Construct a DeclarationDataCenter with given data.
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@ -41,28 +42,35 @@ export class DeclarationDataCenter {
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* @returns {Promise<DeclarationDataCenter>}
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* @returns {Promise<DeclarationDataCenter>}
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*/
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*/
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static async init() {
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static async init() {
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if (!DeclarationDataCenter.singleton) {
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if (DeclarationDataCenter.singleton === null) {
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const dataListUrl = new URL(
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if (DeclarationDataCenter.requestSingleton === null) {
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`${SITE_ROOT}/declarations/declaration-data.bmp`,
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DeclarationDataCenter.requestSingleton = DeclarationDataCenter.getData();
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window.location
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);
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// try to use cache first
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const data = await fetchCachedDeclarationData().catch(_e => null);
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if (data) {
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// if data is defined, use the cached one.
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DeclarationDataCenter.singleton = new DeclarationDataCenter(data);
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} else {
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// undefined. then fetch the data from the server.
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const dataListRes = await fetch(dataListUrl);
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const data = await dataListRes.json();
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await cacheDeclarationData(data);
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DeclarationDataCenter.singleton = new DeclarationDataCenter(data);
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}
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}
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await DeclarationDataCenter.requestSingleton;
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}
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}
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return DeclarationDataCenter.singleton;
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return DeclarationDataCenter.singleton;
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}
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}
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static async getData() {
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const dataListUrl = new URL(
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`${SITE_ROOT}/declarations/declaration-data.bmp`,
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window.location
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);
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// try to use cache first
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const data = await fetchCachedDeclarationData().catch(_e => null);
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if (data) {
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// if data is defined, use the cached one.
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DeclarationDataCenter.singleton = new DeclarationDataCenter(data);
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} else {
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// undefined. then fetch the data from the server.
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const dataListRes = await fetch(dataListUrl);
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const data = await dataListRes.json();
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await cacheDeclarationData(data);
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DeclarationDataCenter.singleton = new DeclarationDataCenter(data);
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}
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}
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/**
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/**
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* Search for a declaration.
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* Search for a declaration.
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* @returns {Array<any>}
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* @returns {Array<any>}
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