pip-services3-components-node/src/lock/NullLock.ts

Component definitions for Pip.Services in Node.js

/** @module lock */
import { ILock } from './ILock';

/**
 * Dummy lock implementation that doesn't do anything.
 * 
 * It can be used in testing or in situations when lock is required
 * but shall be disabled.
 * 
 * @see [[ILock]]
 */
export class NullLock implements ILock {
    /**
     * Makes a single attempt to acquire a lock by its key.
     * It returns immediately a positive or negative result.
     * 
     * @param correlationId     (optional) transaction id to trace execution through call chain.
     * @param key               a unique lock key to acquire.
     * @param ttl               a lock timeout (time to live) in milliseconds.
     * @param callback          callback function that receives a lock result or error.
     */
    public tryAcquireLock(correlationId: string, key: string, ttl: number,
        callback: (err: any, result: boolean) => void): void {
        callback(null, true);
    }

    /**
     * Makes multiple attempts to acquire a lock by its key within give time interval.
     * 
     * @param correlationId     (optional) transaction id to trace execution through call chain. 
     * @param key               a unique lock key to acquire.
     * @param ttl               a lock timeout (time to live) in milliseconds.
     * @param timeout           a lock acquisition timeout.
     * @param callback          callback function that receives error or null for success.
     */
    public acquireLock(correlationId: string, key: string, ttl: number, timeout: number,
        callback: (err: any) => void): void {
        callback(null);
    }

    /**
     * Releases prevously acquired lock by its key.
     * 
     * @param correlationId     (optional) transaction id to trace execution through call chain.
     * @param key               a unique lock key to release.
     * @param callback          callback function that receives error or null for success.
     */
    public releaseLock(correlationId: string, key: string,
        callback?: (err: any) => void): void {
        if (callback) callback(null);
    }
}