pkg/{timex,wait}: Unify code

pkg/timex/timex.go

@@ -1,3 +1,4 @@
+// Package timex provides Interval and Wait
 package timex
 
 import (
@@ -5,21 +6,49 @@ import (
 	"time"
 )
 
-// SetInterval invokes f with the current time and then spawns a new goroutine that runs f every d, until context is closed.
-func SetInterval(ctx context.Context, d time.Duration, f func(t time.Time)) {
-	f(time.Now())
+// TickContext is like [time.Tick], but closes the returned channel once the context closes.
+// As such it can be recovered by the garbage collector; see [time.TickContext].
+//
+// Unlike [time.Tick], immediatly send the current time on the given channel.
+func TickContext(c context.Context, d time.Duration) <-chan time.Time {
+	if d < 0 {
+		return nil
+	}
 
+	timer := make(chan time.Time, 1)
+	timer <- time.Now()
 	go func() {
 		t := time.NewTicker(d)
 		defer t.Stop()
+		defer close(timer)
 
 		for {
 			select {
 			case tick := <-t.C:
-				f(tick)
-			case <-ctx.Done():
+				timer <- tick
+			case <-c.Done():
 				return
 			}
 		}
+
 	}()
+	return timer
+}
+
+// TickUntilFunc invokes f every d until either context is closed, or f returns true.
+// f is invoked once immediatly when the timer starts.
+//
+// TickUntilFunc blocks until f is no longer invoked.
+//
+// Returns the error of the context (if any).
+func TickUntilFunc(f func(t time.Time) bool, c context.Context, d time.Duration) error {
+	context, cancel := context.WithCancel(c)
+	defer cancel()
+
+	for t := range TickContext(context, d) {
+		if f(t) {
+			break
+		}
+	}
+	return c.Err()
 }