index.js

"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
const p_defer_1 = __importDefault(require("p-defer"));
function mapAgeCleaner(map, property = 'maxAge') {
    let processingKey;
    let processingTimer;
    let processingDeferred;
    const cleanup = () => __awaiter(this, void 0, void 0, function* () {
        if (processingKey !== undefined) {
            // If we are already processing an item, we can safely exit
            return;
        }
        const setupTimer = (item) => __awaiter(this, void 0, void 0, function* () {
            processingDeferred = p_defer_1.default();
            const delay = item[1][property] - Date.now();
            if (delay <= 0) {
                // Remove the item immediately if the delay is equal to or below 0
                map.delete(item[0]);
                processingDeferred.resolve();
                return;
            }
            // Keep track of the current processed key
            processingKey = item[0];
            processingTimer = setTimeout(() => {
                // Remove the item when the timeout fires
                map.delete(item[0]);
                if (processingDeferred) {
                    processingDeferred.resolve();
                }
            }, delay);
            // tslint:disable-next-line:strict-type-predicates
            if (typeof processingTimer.unref === 'function') {
                // Don't hold up the process from exiting
                processingTimer.unref();
            }
            return processingDeferred.promise;
        });
        try {
            for (const entry of map) {
                yield setupTimer(entry);
            }
        }
        catch (_a) {
            // Do nothing if an error occurs, this means the timer was cleaned up and we should stop processing
        }
        processingKey = undefined;
    });
    const reset = () => {
        processingKey = undefined;
        if (processingTimer !== undefined) {
            clearTimeout(processingTimer);
            processingTimer = undefined;
        }
        if (processingDeferred !== undefined) { // tslint:disable-line:early-exit
            processingDeferred.reject(undefined);
            processingDeferred = undefined;
        }
    };
    const originalSet = map.set.bind(map);
    map.set = (key, value) => {
        if (map.has(key)) {
            // If the key already exist, remove it so we can add it back at the end of the map.
            map.delete(key);
        }
        // Call the original `map.set`
        const result = originalSet(key, value);
        // If we are already processing a key and the key added is the current processed key, stop processing it
        if (processingKey && processingKey === key) {
            reset();
        }
        // Always run the cleanup method in case it wasn't started yet
        cleanup(); // tslint:disable-line:no-floating-promises
        return result;
    };
    cleanup(); // tslint:disable-line:no-floating-promises
    return map;
}
exports.default = mapAgeCleaner;
// Add support for CJS
module.exports = mapAgeCleaner;
module.exports.default = mapAgeCleaner;