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72 lines
2.0 KiB
72 lines
2.0 KiB
function flru(max) {
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var num, curr, prev;
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var limit = max || 1;
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function keep(key, value) {
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if (++num > limit) {
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prev = curr;
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reset(1);
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++num;
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}
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curr[key] = value;
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}
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function reset(isPartial) {
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num = 0;
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curr = Object.create(null);
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isPartial || (prev = Object.create(null));
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}
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reset();
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return {
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clear: reset,
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has: function (key) {
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return curr[key] !== void 0 || prev[key] !== void 0;
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},
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get: function (key) {
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var val = curr[key];
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if (val !== void 0)
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return val;
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if ((val = prev[key]) !== void 0) {
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keep(key, val);
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return val;
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}
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},
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set: function (key, value) {
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if (curr[key] !== void 0) {
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curr[key] = value;
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}
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else {
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keep(key, value);
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}
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},
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};
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}
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var CacheMap = new Map();
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/**
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* 缓存函数的计算结果，避免重复计算
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* @example
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* _.memoize(calColor);
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* _.memoize(calColor, (...args) => args[0]);
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* @param fn 缓存的函数
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* @param resolver 生成缓存 key 的函数
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* @param maxSize lru 缓存的大小
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*/
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export default function memoize(fn, resolver, maxSize) {
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if (maxSize === void 0) { maxSize = 128; }
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var memoized = function () {
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var args = [];
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for (var _i = 0; _i < arguments.length; _i++) {
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args[_i] = arguments[_i];
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}
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// 使用方法构造 key，如果不存在 resolver，则直接取第一个参数作为 key
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var key = resolver ? resolver.apply(this, args) : args[0];
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if (!CacheMap.has(fn))
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CacheMap.set(fn, flru(maxSize));
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var cache = CacheMap.get(fn);
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if (cache.has(key))
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return cache.get(key);
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var result = fn.apply(this, args);
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cache.set(key, result);
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return result;
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};
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return memoized;
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}
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//# sourceMappingURL=memoize.js.map
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