node-anemometer/dist/utils/History.js

Measuring the wind speed with an anemometer

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.History = void 0;
/**
 * Represents a history of data records.
 */
class History {
    expirationTime;
    maxElements;
    /**
     * **Flow direction:**
     * old data  <--  new data
     */
    data = [];
    /**
     * Creates a new instance of the History class.
     *
     * @param expirationTime Specifies after how many seconds a data record should be deleted.
     * @param maxElements Specifies the maximum number of data records to be stored. 0 means no limit.
     */
    constructor(expirationTime = 600, maxElements = 700) {
        this.expirationTime = expirationTime;
        this.maxElements = maxElements;
    }
    /**
     * Returns the current Unix timestamp in seconds.
     *
     * @returns The current Unix timestamp.
     */
    getUnixTS() {
        return Math.floor(new Date().getTime() / 1000);
    }
    /**
     * Inserts a new data record into the history.
     *
     * @param value The value to be added to the history.
     */
    push(value) {
        if (this.maxElements > 0 && this.data.length + 1 >= this.maxElements) {
            this.data.shift();
        }
        this.data.push({ value, timestamp: this.getUnixTS() });
    }
    /**
     * Retrieves data records based on specified conditions.
     *
     * @param conditions The conditions to filter the data records.
     * @returns An array of data records that match the conditions.
     */
    get(conditions) {
        let result = this.data.slice(0);
        // Filter by startTime and endTime
        if ('startTime' in conditions || 'endTime' in conditions) {
            const startTime = conditions.startTime ? Math.floor(conditions.startTime.getTime() / 1000) : -Infinity;
            const endTime = conditions.endTime ? Math.floor(conditions.endTime.getTime() / 1000) : Infinity;
            result = result.filter((record) => record.timestamp >= startTime && record.timestamp <= endTime);
        }
        // Filter by offset (timestamp in seconds from current time)
        if ('recentSeconds' in conditions && conditions.recentSeconds !== undefined) {
            const recentTime = this.getUnixTS() - conditions.recentSeconds;
            result = result.filter((record) => record.timestamp >= recentTime);
        }
        // Sort by order
        if (conditions.order && conditions.order.toLowerCase() === 'asc') {
            result = result.sort((a, b) => a.timestamp - b.timestamp);
        }
        // Limit the number of results
        if (conditions.limit && conditions.limit > 0) {
            result = result.slice(0, conditions.limit);
        }
        return result;
    }
    /**
     * Removes outdated data records from the history.
     */
    clean() {
        const beginOfValidData = this.getUnixTS() - this.expirationTime + 1;
        if (this.maxElements > 0) {
            this.data = this.data.slice(-this.maxElements);
        }
        this.data = this.data.filter((record) => record.timestamp >= beginOfValidData);
    }
}
exports.History = History;