47 lines
1.1 KiB
JavaScript
47 lines
1.1 KiB
JavaScript
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var TimeLimitedCache = function() {
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this.cache = new Map();
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};
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/**
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* @param {number} key
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* @param {number} value
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* @param {number} time until expiration in ms
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* @return {boolean} if un-expired key already existed
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*/
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TimeLimitedCache.prototype.set = function(key, value, duration) {
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const existing = this.cache.get(key);
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if (existing) {
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clearTimeout(existing.ttl);
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}
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const ttl = setTimeout(() => this.cache.delete(key), duration);
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this.cache.set(key, { value, ttl });
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return Boolean(existing);
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};
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/**
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* @param {number} key
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* @return {number} value associated with key
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*/
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TimeLimitedCache.prototype.get = function(key) {
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if (!this.cache.has(key)) {
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return -1;
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}
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return this.cache.get(key).value;
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};
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/**
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* @return {number} count of non-expired keys
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*/
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TimeLimitedCache.prototype.count = function() {
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return this.cache.size;
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};
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/**
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* Your TimeLimitedCache object will be instantiated and called as such:
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* var obj = new TimeLimitedCache()
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* obj.set(1, 42, 1000); // false
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* obj.get(1) // 42
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* obj.count() // 1
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*/
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