FixedRateTimer

Implements: IClosable

Description

The FixerRateTimer class represents a timer that is triggered in equal time intervals.

Important points

• It has symmetric cross-language implementation and is often used by the Pip.Services toolkit to perform periodic processing and cleanup in microservices.

Constructors

Creates new instance of the timer and sets its values.

public constructor(taskOrCallback: any = null, interval: number = null, delay: number = null)

• taskOrCallback: any - (optional) Notifiable object or callback function to call when timer is triggered.
• interval: number - (optional) interval to trigger timer in milliseconds.
• delay: number - (optional) delay before the first triggering in milliseconds.

Instance methods

close

Closes the timer.

This is required by the IClosable interface, but besides that it is identical to stop().

public close(correlationId: string): Promise<void>

• correlationId: string - (optional) transaction id used to trace execution through the call chain.

getCallback

Gets the callback function that is called when this timer is triggered.

public getCallback(): () => void

• returns: function - callback function or null if it is not set.

getDelay

Gets an initial delay before the timer is triggered for the first time.

public getDelay(): number

• returns: number - delay in milliseconds.

getInterval

Gets a periodic timer triggering interval.

public getInterval(): number

• returns: number - interval in milliseconds

getTask

Gets the INotifiable object that receives notifications from this timer.

public getTask(): INotifiable

• returns: INotifiable - INotifiable object or null if it is not set.

setTask

Sets a new INotifiable object to receive notifications from this timer.

public setTask(value: INotifiable): void

• value: INotifiable - INotifiable object to be triggered.

isStarted

Checks if the timer is started.

public isStarted(): boolean

• returns: boolean - true if the timer is started and false if it is stopped.

setCallback

Sets the callback function that is called when this timer is triggered.

public setCallback(value: () => void)

• value: function - callback function to be called.

setDelay

Sets an initial delay before the timer is triggered for the first time.

public setDelay(value: number): void

• value: number - delay in milliseconds.

setInterval

Sets a periodic timer triggering interval.

public setInterval(value: number): void

• value: number - interval in milliseconds.

start

Starts the timer.

Initially. the timer is triggered after delay. After that, it is triggered after interval until it is stopped.

public start(): void

stop

Stops the timer.

public stop(): void

Examples

class MyComponent {
    private timer: FixedRateTimer = new FixedRateTimer(() => { this.cleanup }, 60000);
    ...
    public async open(correlationId: string): Promise<void> {
        ...
        timer.start();
        ...
    }
    
    public async close(correlationId: string): Promise<void> {
        ...
        timer.stop();
        ...
    }
    
    private cleanup(): void {
        ...
    }
    ...
}

See also

• INotifiable