pip-services3-components-nodex/src/cache/CacheEntry.ts

Component definitions for Pip.Services in Node.js / ES2017

/** @module cache */

/**
 * Data object to store cached values with their keys used by [[MemoryCache]]
 */
export class CacheEntry {
    private _key: string;
    private _value: any;
    private _expiration: number;

    /**
     * Creates a new instance of the cache entry and assigns its values.
     * 
     * @param key       a unique key to locate the value.
     * @param value     a value to be stored.
     * @param timeout   expiration timeout in milliseconds.
     */
    public constructor(key: string, value: any, timeout: number) {
        this._key = key;
        this._value = value;
        this._expiration = new Date().getTime() + timeout;
    }

    /**
     * Gets the key to locate the cached value.
     * 
     * @returns the value key.
     */
    public getKey(): string {
        return this._key;
    }

    /**
     * Gets the cached value.
     * 
     * @returns the value object.
     */
    public getValue(): any {
        return this._value;
    }

    /**
     * Gets the expiration timeout.
     * 
     * @returns the expiration timeout in milliseconds.
     */
    public getExpiration(): number {
        return this._expiration;
    }

    /**
     * Sets a new value and extends its expiration.
     * 
     * @param value     a new cached value.
     * @param timeout   a expiration timeout in milliseconds.
     */
    public setValue(value: any, timeout: number): void {
        this._value = value;
        this._expiration = new Date().getTime() + timeout;
    }

    /**
     * Checks if this value already expired.
     * 
     * @returns true if the value already expires and false otherwise.
     */
    public isExpired(): boolean {
        return this._expiration < new Date().getTime();
    }

}