Kas saaksite anda näiteid WithCancel, WithTimeout ja WithDeadline kasutamisest?

In the context package of Go, there are functions to create contexts with the ability to cancel and set execution time limits:

• WithCancel — creates a context that can be manually canceled by calling the cancel() function. Used when you need to interrupt an operation upon an event.

• WithTimeout — creates a context that automatically cancels after a specified duration.

• WithDeadline — creates a context that cancels at a specific time.

Examples:

ctx, cancel := context.WithCancel(context.Background())
// Start a goroutine that will cancel the context after 2 seconds
//
go func() {
    time.Sleep(2 * time.Second)
    cancel()
}()

select {
case <-ctx.Done():
    fmt.Println("Operation canceled")
}

// WithTimeout
ctxTimeout, cancelTimeout := context.WithTimeout(context.Background(), 3*time.Second)
defer cancelTimeout()
// operation that will be interrupted after 3 seconds

// WithDeadline
deadline := time.Now().Add(5 * time.Second)
ctxDeadline, cancelDeadline := context.WithDeadline(context.Background(), deadline)
defer cancelDeadline()
// operation that will be interrupted at the specified time

These mechanisms are useful for controlling request execution time, canceling long operations, and managing resources.