47 lines
1.1 KiB
JavaScript
47 lines
1.1 KiB
JavaScript
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/**
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* Wrap an async function to cache its result.
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*
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* On first call of the wrapped function, the result will be stored and further
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* calls will directly return this cached value (always inside a promise).
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*
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* A `.noCache` method is provided to force getting a fresh value.
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*
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* Each cache value is scoped to the array of arguments that yielded it
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* (comparison done using its JSON representation).
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*
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* @param fun Function to wrap.
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* @return Wrapped function.
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*/
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const makeCached = fun =>
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{
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const cachedResults = new Map();
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const noCache = async (...args) =>
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{
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const result = await fun(...args);
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cachedResults.set(JSON.stringify(args), result);
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return result;
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};
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const withCache = async (...args) =>
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{
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const key = JSON.stringify(args);
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if (cachedResults.has(key))
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{
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return cachedResults.get(key);
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}
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else
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{
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const result = await fun(...args);
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cachedResults.set(key, result);
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return result;
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}
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};
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withCache.noCache = noCache;
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return withCache;
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};
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exports.makeCached = makeCached;
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