connection-scan-algorithm/dist/csa/ConnectionScanAlgorithm.js

Connection Scan Algorithm

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
/**
 * Implementation of the connection scan algorithm.
 */
class ConnectionScanAlgorithm {
    constructor(connections, transfers, resultsFactory) {
        this.connections = connections;
        this.transfers = transfers;
        this.resultsFactory = resultsFactory;
    }
    /**
     * Return an index of connections that achieve the earliest arrival time at each stop.
     */
    scan(origins, destinations, date, dow) {
        const results = this.resultsFactory.create({ ...origins });
        for (const origin in origins) {
            this.scanTransfers(results, origin);
        }
        for (const c of this.connections) {
            if (c.trip.service.runsOn(date, dow) && results.isReachable(c) && results.isBetter(c)) {
                const newStopReached = results.setConnection(c);
                if (newStopReached) {
                    this.scanTransfers(results, c.destination);
                }
                if (results.isFinished(destinations, c.departureTime)) {
                    break;
                }
            }
        }
        return results.getConnectionIndex();
    }
    scanTransfers(results, origin) {
        for (const transfer of this.transfers[origin]) {
            if (results.isTransferBetter(transfer)) {
                const newStopReached = results.setTransfer(transfer);
                if (newStopReached) {
                    this.scanTransfers(results, transfer.destination);
                }
            }
        }
    }
}
exports.ConnectionScanAlgorithm = ConnectionScanAlgorithm;