quick-lru-ts
Version:
Simple “Least Recently Used” (LRU) cache
556 lines (548 loc) • 22.1 kB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
exports.QuickLRU = void 0;
var QuickLRU = /** @class */ (function () {
/**
Simple ["Least Recently Used" (LRU) cache](https://en.m.wikipedia.org/wiki/Cache_replacement_policies#Least_Recently_Used_.28LRU.29).
The instance is an [`Iterable`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Iteration_protocols) of `[key, value]` pairs so you can use it directly in a [`for…of`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/for...of) loop.
@example
```
import { QuickLRU } from 'quick-lru-ts';
const lru = new QuickLRU({maxSize: 1000});
lru.set('🦄', '🌈');
lru.has('🦄');
//=> true
lru.get('🦄');
//=> '🌈'
```
*/
function QuickLRU(options) {
if (!(options.maxSize && options.maxSize > 0)) {
throw new TypeError("`maxSize` must be a number greater than 0");
}
if (typeof options.maxAge === "number" && options.maxAge === 0) {
throw new TypeError("`maxAge` must be a number greater than 0");
}
// TODO: Use private class fields when ESLint supports them.
this.maxSize = options.maxSize;
this.maxAge = options.maxAge || Number.POSITIVE_INFINITY;
this.onEviction = options.onEviction;
this.cache = new Map();
this.oldCache = new Map();
this._size = 0;
}
// TODO: Use private class methods when targeting Node.js 16.
QuickLRU.prototype._emitEvictions = function (cache) {
var e_1, _a;
if (typeof this.onEviction !== "function") {
return;
}
try {
for (var cache_1 = __values(cache), cache_1_1 = cache_1.next(); !cache_1_1.done; cache_1_1 = cache_1.next()) {
var _b = __read(cache_1_1.value, 2), key = _b[0], item = _b[1];
this.onEviction(key, item.value);
}
}
catch (e_1_1) { e_1 = { error: e_1_1 }; }
finally {
try {
if (cache_1_1 && !cache_1_1.done && (_a = cache_1.return)) _a.call(cache_1);
}
finally { if (e_1) throw e_1.error; }
}
};
QuickLRU.prototype._deleteIfExpired = function (key, item) {
if (item === undefined)
return true;
if (typeof item.expiry === "number" && item.expiry <= Date.now()) {
if (typeof this.onEviction === "function") {
this.onEviction(key, item.value);
}
return this.delete(key);
}
return false;
};
QuickLRU.prototype._getOrDeleteIfExpired = function (key, item) {
var deleted = this._deleteIfExpired(key, item);
if (deleted === false) {
return item.value;
}
};
QuickLRU.prototype._getItemValue = function (key, item) {
if (item === undefined)
return undefined;
return item.expiry ? this._getOrDeleteIfExpired(key, item) : item.value;
};
QuickLRU.prototype._peek = function (key, cache) {
var item = cache.get(key);
return this._getItemValue(key, item);
};
QuickLRU.prototype._set = function (key, value) {
this.cache.set(key, value);
this._size++;
if (this._size >= this.maxSize) {
this._size = 0;
this._emitEvictions(this.oldCache);
this.oldCache = this.cache;
this.cache = new Map();
}
};
QuickLRU.prototype._moveToRecent = function (key, item) {
this.oldCache.delete(key);
this._set(key, item);
};
QuickLRU.prototype._entriesAscending = function () {
var _a, _b, item, _c, key, value, deleted, e_2_1, _d, _e, item, _f, key, value, deleted, e_3_1;
var e_2, _g, e_3, _h;
return __generator(this, function (_j) {
switch (_j.label) {
case 0:
_j.trys.push([0, 5, 6, 7]);
_a = __values(this.oldCache), _b = _a.next();
_j.label = 1;
case 1:
if (!!_b.done) return [3 /*break*/, 4];
item = _b.value;
_c = __read(item, 2), key = _c[0], value = _c[1];
if (!!this.cache.has(key)) return [3 /*break*/, 3];
deleted = this._deleteIfExpired(key, value);
if (!(deleted === false)) return [3 /*break*/, 3];
return [4 /*yield*/, item];
case 2:
_j.sent();
_j.label = 3;
case 3:
_b = _a.next();
return [3 /*break*/, 1];
case 4: return [3 /*break*/, 7];
case 5:
e_2_1 = _j.sent();
e_2 = { error: e_2_1 };
return [3 /*break*/, 7];
case 6:
try {
if (_b && !_b.done && (_g = _a.return)) _g.call(_a);
}
finally { if (e_2) throw e_2.error; }
return [7 /*endfinally*/];
case 7:
_j.trys.push([7, 12, 13, 14]);
_d = __values(this.cache), _e = _d.next();
_j.label = 8;
case 8:
if (!!_e.done) return [3 /*break*/, 11];
item = _e.value;
_f = __read(item, 2), key = _f[0], value = _f[1];
deleted = this._deleteIfExpired(key, value);
if (!(deleted === false)) return [3 /*break*/, 10];
return [4 /*yield*/, item];
case 9:
_j.sent();
_j.label = 10;
case 10:
_e = _d.next();
return [3 /*break*/, 8];
case 11: return [3 /*break*/, 14];
case 12:
e_3_1 = _j.sent();
e_3 = { error: e_3_1 };
return [3 /*break*/, 14];
case 13:
try {
if (_e && !_e.done && (_h = _d.return)) _h.call(_d);
}
finally { if (e_3) throw e_3.error; }
return [7 /*endfinally*/];
case 14: return [2 /*return*/];
}
});
};
/**
Get an item.
@returns The stored item or `undefined`.
*/
QuickLRU.prototype.get = function (key) {
if (this.cache.has(key)) {
var item = this.cache.get(key);
return this._getItemValue(key, item);
}
if (this.oldCache.has(key)) {
var item = this.oldCache.get(key);
if (this._deleteIfExpired(key, item) === false) {
this._moveToRecent(key, item);
return item.value;
}
}
};
QuickLRU.prototype.set = function (key, value, _a) {
var _b = _a === void 0 ? {} : _a, _c = _b.maxAge, maxAge = _c === void 0 ? this.maxAge : _c;
var expiry = typeof maxAge === "number" && maxAge !== Number.POSITIVE_INFINITY
? Date.now() + maxAge
: undefined;
if (this.cache.has(key)) {
this.cache.set(key, {
value: value,
expiry: expiry,
});
}
else {
this._set(key, { value: value, expiry: expiry });
}
};
QuickLRU.prototype.has = function (key) {
if (this.cache.has(key)) {
return !this._deleteIfExpired(key, this.cache.get(key));
}
if (this.oldCache.has(key)) {
return !this._deleteIfExpired(key, this.oldCache.get(key));
}
return false;
};
QuickLRU.prototype.peek = function (key) {
if (this.cache.has(key)) {
return this._peek(key, this.cache);
}
if (this.oldCache.has(key)) {
return this._peek(key, this.oldCache);
}
};
QuickLRU.prototype.delete = function (key) {
var deleted = this.cache.delete(key);
if (deleted) {
this._size--;
}
return this.oldCache.delete(key) || deleted;
};
QuickLRU.prototype.clear = function () {
this.cache.clear();
this.oldCache.clear();
this._size = 0;
};
QuickLRU.prototype.resize = function (maxSize) {
if (!(maxSize && maxSize > 0)) {
throw new TypeError("`maxSize` must be a number greater than 0");
}
var items = __spreadArray([], __read(this._entriesAscending()), false);
var removeCount = items.length - maxSize;
if (removeCount < 0) {
this.cache = new Map(items);
this.oldCache = new Map();
this._size = items.length;
}
else {
if (removeCount > 0) {
this._emitEvictions(items.slice(0, removeCount));
}
this.oldCache = new Map(items.slice(removeCount));
this.cache = new Map();
this._size = 0;
}
this.maxSize = maxSize;
};
QuickLRU.prototype.keys = function () {
var _a, _b, _c, key, e_4_1;
var e_4, _d;
return __generator(this, function (_e) {
switch (_e.label) {
case 0:
_e.trys.push([0, 5, 6, 7]);
_a = __values(this), _b = _a.next();
_e.label = 1;
case 1:
if (!!_b.done) return [3 /*break*/, 4];
_c = __read(_b.value, 1), key = _c[0];
return [4 /*yield*/, key];
case 2:
_e.sent();
_e.label = 3;
case 3:
_b = _a.next();
return [3 /*break*/, 1];
case 4: return [3 /*break*/, 7];
case 5:
e_4_1 = _e.sent();
e_4 = { error: e_4_1 };
return [3 /*break*/, 7];
case 6:
try {
if (_b && !_b.done && (_d = _a.return)) _d.call(_a);
}
finally { if (e_4) throw e_4.error; }
return [7 /*endfinally*/];
case 7: return [2 /*return*/];
}
});
};
QuickLRU.prototype.values = function () {
var _a, _b, _c, value, e_5_1;
var e_5, _d;
return __generator(this, function (_e) {
switch (_e.label) {
case 0:
_e.trys.push([0, 5, 6, 7]);
_a = __values(this), _b = _a.next();
_e.label = 1;
case 1:
if (!!_b.done) return [3 /*break*/, 4];
_c = __read(_b.value, 2), value = _c[1];
return [4 /*yield*/, value];
case 2:
_e.sent();
_e.label = 3;
case 3:
_b = _a.next();
return [3 /*break*/, 1];
case 4: return [3 /*break*/, 7];
case 5:
e_5_1 = _e.sent();
e_5 = { error: e_5_1 };
return [3 /*break*/, 7];
case 6:
try {
if (_b && !_b.done && (_d = _a.return)) _d.call(_a);
}
finally { if (e_5) throw e_5.error; }
return [7 /*endfinally*/];
case 7: return [2 /*return*/];
}
});
};
QuickLRU.prototype[Symbol.iterator] = function () {
var _a, _b, item, _c, key, value, deleted, e_6_1, _d, _e, item, _f, key, value, deleted, e_7_1;
var e_6, _g, e_7, _h;
return __generator(this, function (_j) {
switch (_j.label) {
case 0:
_j.trys.push([0, 5, 6, 7]);
_a = __values(this.cache), _b = _a.next();
_j.label = 1;
case 1:
if (!!_b.done) return [3 /*break*/, 4];
item = _b.value;
_c = __read(item, 2), key = _c[0], value = _c[1];
deleted = this._deleteIfExpired(key, value);
if (!(deleted === false)) return [3 /*break*/, 3];
return [4 /*yield*/, [key, value.value]];
case 2:
_j.sent();
_j.label = 3;
case 3:
_b = _a.next();
return [3 /*break*/, 1];
case 4: return [3 /*break*/, 7];
case 5:
e_6_1 = _j.sent();
e_6 = { error: e_6_1 };
return [3 /*break*/, 7];
case 6:
try {
if (_b && !_b.done && (_g = _a.return)) _g.call(_a);
}
finally { if (e_6) throw e_6.error; }
return [7 /*endfinally*/];
case 7:
_j.trys.push([7, 12, 13, 14]);
_d = __values(this.oldCache), _e = _d.next();
_j.label = 8;
case 8:
if (!!_e.done) return [3 /*break*/, 11];
item = _e.value;
_f = __read(item, 2), key = _f[0], value = _f[1];
if (!!this.cache.has(key)) return [3 /*break*/, 10];
deleted = this._deleteIfExpired(key, value);
if (!(deleted === false)) return [3 /*break*/, 10];
return [4 /*yield*/, [key, value.value]];
case 9:
_j.sent();
_j.label = 10;
case 10:
_e = _d.next();
return [3 /*break*/, 8];
case 11: return [3 /*break*/, 14];
case 12:
e_7_1 = _j.sent();
e_7 = { error: e_7_1 };
return [3 /*break*/, 14];
case 13:
try {
if (_e && !_e.done && (_h = _d.return)) _h.call(_d);
}
finally { if (e_7) throw e_7.error; }
return [7 /*endfinally*/];
case 14: return [2 /*return*/];
}
});
};
/**
Iterable for all entries, starting with the newest (descending in recency).
*/
QuickLRU.prototype.entriesDescending = function () {
var items, i, item, _a, key, value, deleted, i, item, _b, key, value, deleted;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
items = __spreadArray([], __read(this.cache), false);
i = items.length - 1;
_c.label = 1;
case 1:
if (!(i >= 0)) return [3 /*break*/, 4];
item = items[i];
_a = __read(item, 2), key = _a[0], value = _a[1];
deleted = this._deleteIfExpired(key, value);
if (!(deleted === false)) return [3 /*break*/, 3];
return [4 /*yield*/, [key, value.value]];
case 2:
_c.sent();
_c.label = 3;
case 3:
--i;
return [3 /*break*/, 1];
case 4:
items = __spreadArray([], __read(this.oldCache), false);
i = items.length - 1;
_c.label = 5;
case 5:
if (!(i >= 0)) return [3 /*break*/, 8];
item = items[i];
_b = __read(item, 2), key = _b[0], value = _b[1];
if (!!this.cache.has(key)) return [3 /*break*/, 7];
deleted = this._deleteIfExpired(key, value);
if (!(deleted === false)) return [3 /*break*/, 7];
return [4 /*yield*/, [key, value.value]];
case 6:
_c.sent();
_c.label = 7;
case 7:
--i;
return [3 /*break*/, 5];
case 8: return [2 /*return*/];
}
});
};
QuickLRU.prototype.entriesAscending = function () {
var _a, _b, _c, key, value, e_8_1;
var e_8, _d;
return __generator(this, function (_e) {
switch (_e.label) {
case 0:
_e.trys.push([0, 5, 6, 7]);
_a = __values(this._entriesAscending()), _b = _a.next();
_e.label = 1;
case 1:
if (!!_b.done) return [3 /*break*/, 4];
_c = __read(_b.value, 2), key = _c[0], value = _c[1];
return [4 /*yield*/, [key, value.value]];
case 2:
_e.sent();
_e.label = 3;
case 3:
_b = _a.next();
return [3 /*break*/, 1];
case 4: return [3 /*break*/, 7];
case 5:
e_8_1 = _e.sent();
e_8 = { error: e_8_1 };
return [3 /*break*/, 7];
case 6:
try {
if (_b && !_b.done && (_d = _a.return)) _d.call(_a);
}
finally { if (e_8) throw e_8.error; }
return [7 /*endfinally*/];
case 7: return [2 /*return*/];
}
});
};
Object.defineProperty(QuickLRU.prototype, "size", {
get: function () {
var e_9, _a;
if (!this._size) {
return this.oldCache.size;
}
var oldCacheSize = 0;
try {
for (var _b = __values(this.oldCache.keys()), _c = _b.next(); !_c.done; _c = _b.next()) {
var key = _c.value;
if (!this.cache.has(key)) {
oldCacheSize++;
}
}
}
catch (e_9_1) { e_9 = { error: e_9_1 }; }
finally {
try {
if (_c && !_c.done && (_a = _b.return)) _a.call(_b);
}
finally { if (e_9) throw e_9.error; }
}
return Math.min(this._size + oldCacheSize, this.maxSize);
},
enumerable: false,
configurable: true
});
return QuickLRU;
}());
exports.QuickLRU = QuickLRU;