@newdash/newdash/functional/TTLMap.js

javascript/typescript utility library

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.TTLMap = void 0;
/**
 * TTL (Time to Life) Map
 *
 * it will lazy remove values when perform operations
 *
 * @category Functional
 * @since 5.18.0
 */
class TTLMap extends Map {
    /**
     * TTLMap (Time to Life) Map
     *
     * it will lazy remove values when perform operations
     *
     * @param defaultTTL time to live, in milliseconds, default value is 60 seconds
     * @param cleanAfterOperation execute full clean after operations. default value is 100, it means, at least 100 operations performed, the TTL evict logic will be executed
     */
    constructor(defaultTTL = 60 * 1000, cleanAfterOperation = 100) {
        super();
        this.defaultTTL = defaultTTL;
        this.timeoutStorage = new Map();
        if (cleanAfterOperation > 1) {
            this.cleanAfterOperation = cleanAfterOperation;
        }
        this.operationCount = 0;
    }
    /**
     * default TTL value in milliseconds
     */
    defaultTTL;
    cleanAfterOperation;
    operationCount;
    timeoutStorage;
    timestamp() {
        return Date.now();
    }
    /**
     * _checkAndClean
     *
     * for the simple operations (set/get/delete/has), the clean operation will not execute every time
     */
    _checkAndClean() {
        if (this.operationCount++ > this.cleanAfterOperation) {
            this.operationCount = 0;
            this.cleanTimeoutItems();
        }
    }
    /**
     * set value
     *
     * @param k key
     * @param v value
     * @param ttl time to live, in milliseconds, if undefined, will use instance level defaultTTL
     * @returns
     */
    set(k, v, ttl = this.defaultTTL) {
        const expireTime = this.timestamp() + ttl - 1; // sub 1 to fix very accurate wait
        this._checkAndClean();
        super.set(k, v);
        this.timeoutStorage.set(k, expireTime); // refresh timeout
        return this;
    }
    has(k) {
        this._checkAndClean();
        let rt = false;
        if (super.has(k)) {
            const isTimeout = this.checkTimeout(k);
            if (isTimeout) {
                rt = false;
            }
            else {
                rt = true;
            }
        }
        return rt;
    }
    get(k) {
        this._checkAndClean();
        let rt = undefined;
        if (super.has(k)) {
            const isTimeout = this.checkTimeout(k);
            if (isTimeout) {
                rt = undefined;
            }
            else {
                rt = super.get(k);
            }
        }
        return rt;
    }
    delete(k) {
        this._checkAndClean();
        const rt = super.delete(k);
        this.timeoutStorage.delete(k);
        return rt;
    }
    clear() {
        super.clear();
        this.timeoutStorage.clear();
        this.operationCount = 0;
    }
    /**
     * return true if timeout
     *
     * @param k
     */
    checkTimeout(k, currentTimeStamp = this.timestamp()) {
        const isTimeout = this.getTimeout(k) < currentTimeStamp;
        if (isTimeout) {
            super.delete(k);
            this.timeoutStorage.delete(k);
        }
        return isTimeout;
    }
    getTimeout(k) {
        if (this.timeoutStorage.has(k)) {
            return this.timeoutStorage.get(k);
        }
        return 0;
    }
    /**
     * manually directly clean all timeout items
     */
    cleanTimeoutItems() {
        const current = this.timestamp();
        super.forEach((_, key) => { this.checkTimeout(key, current); });
    }
    entries() {
        this.cleanTimeoutItems();
        return super.entries();
    }
    keys() {
        this.cleanTimeoutItems();
        return super.keys();
    }
    values() {
        this.cleanTimeoutItems();
        return super.values();
    }
    forEach(callbackfn, thisArg) {
        this.cleanTimeoutItems();
        return super.forEach(callbackfn, thisArg);
    }
    get size() {
        this.cleanTimeoutItems();
        // @ts-ignore
        return super.size;
    }
}
exports.TTLMap = TTLMap;
exports.default = TTLMap;