*** title: "JobQueueService" generated: true --------------- The JobQueueService is used to create new [JobQueue](/current/core/reference/typescript-api/job-queue/#jobqueue) instances and access existing jobs. *Example* ```ts // A service which transcodes video files class VideoTranscoderService { private jobQueue: JobQueue<{ videoId: string; }>; async onModuleInit() { // The JobQueue is created on initialization this.jobQueue = await this.jobQueueService.createQueue({ name: 'transcode-video', process: async job => { return await this.transcodeVideo(job.data.videoId); }, }); } addToTranscodeQueue(videoId: string) { this.jobQueue.add({ videoId, }) } private async transcodeVideo(videoId: string) { // e.g. call some external transcoding service } } ``` ```ts title="Signature" class JobQueueService implements OnModuleDestroy { started: boolean constructor(configService: ConfigService, jobBufferService: JobBufferService) createQueue(options: CreateQueueOptions) => Promise>; start() => Promise; addBuffer(buffer: JobBuffer) => ; removeBuffer(buffer: JobBuffer) => ; bufferSize(forBuffers: Array | string>) => Promise<{ [bufferId: string]: number }>; flush(forBuffers: Array | string>) => Promise; getJobQueues() => GraphQlJobQueue[]; } ``` * Implements: OnModuleDestroy
### started \ Returns `true` if the job queues have been started. ### createQueue \CreateQueueOptions) => Promise<JobQueue>`} /> Configures and creates a new [JobQueue](/current/core/reference/typescript-api/job-queue/#jobqueue) instance. ### start \ Promise`} /> ### addBuffer \JobBuffer) => `} since="1.3.0" /> Adds a [JobBuffer](/current/core/reference/typescript-api/job-queue/job-buffer#jobbuffer), which will make it active and begin collecting jobs to buffer. ### removeBuffer \JobBuffer) => `} since="1.3.0" /> Removes a [JobBuffer](/current/core/reference/typescript-api/job-queue/job-buffer#jobbuffer), prevent it from collecting and buffering any subsequent jobs. ### bufferSize \JobBuffer | string>) => Promise<{ [bufferId: string]: number }>`} since="1.3.0" /> Returns an object containing the number of buffered jobs arranged by bufferId. This can be used to decide whether a particular buffer has any jobs to flush. Passing in JobBuffer instances *or* ids limits the results to the specified JobBuffers. If no argument is passed, sizes will be returned for *all* JobBuffers. *Example* ```ts const sizes = await this.jobQueueService.bufferSize('buffer-1', 'buffer-2'); // sizes = { 'buffer-1': 12, 'buffer-2': 3 } ``` ### flush \JobBuffer | string>) => Promise<Job[]>`} since="1.3.0" /> Flushes the specified buffers, which means that the buffer is cleared and the jobs get sent to the job queue for processing. Before sending the jobs to the job queue, they will be passed through each JobBuffer's `reduce()` method, which is can be used to optimize the amount of work to be done by e.g. de-duplicating identical jobs or aggregating data over the collected jobs. Passing in JobBuffer instances *or* ids limits the action to the specified JobBuffers. If no argument is passed, *all* JobBuffers will be flushed. Returns an array of all Jobs which were added to the job queue. ### getJobQueues \ GraphQlJobQueue[]`} /> Returns an array of `{ name: string; running: boolean; }` for each registered JobQueue.