Refactorings for simplify readability (#35)

internal/controller/notifier/notifier.go

@@ -0,0 +1,57 @@
+package notifier
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/cirruslabs/orchard/internal/concurrentmap"
+	"github.com/cirruslabs/orchard/rpc"
+)
+
+var ErrNoWorker = errors.New("no worker registered with this name")
+
+type Notifier struct {
+	workers *concurrentmap.ConcurrentMap[*WorkerSlot]
+}
+
+type WorkerSlot struct {
+	ctx context.Context
+	ch  chan *rpc.WatchInstruction
+}
+
+func NewNotifier() *Notifier {
+	return &Notifier{
+		workers: concurrentmap.NewConcurrentMap[*WorkerSlot](),
+	}
+}
+
+func (watcher *Notifier) Register(ctx context.Context, workerUID string) (chan *rpc.WatchInstruction, func()) {
+	subCtx, cancel := context.WithCancel(ctx)
+	workerCh := make(chan *rpc.WatchInstruction)
+
+	watcher.workers.Store(workerUID, &WorkerSlot{
+		ctx: subCtx,
+		ch:  workerCh,
+	})
+
+	return workerCh, func() {
+		watcher.workers.Delete(workerUID)
+		cancel()
+	}
+}
+
+func (watcher *Notifier) Notify(ctx context.Context, workerUID string, msg *rpc.WatchInstruction) error {
+	slot, ok := watcher.workers.Load(workerUID)
+	if !ok {
+		return fmt.Errorf("%w: %s", ErrNoWorker, workerUID)
+	}
+
+	select {
+	case slot.ch <- msg:
+		return nil
+	case <-slot.ctx.Done():
+		return slot.ctx.Err()
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}

internal/controller/notifier/notifier_test.go

@@ -0,0 +1,48 @@
+package notifier_test
+
+import (
+	"context"
+	"fmt"
+	"github.com/cirruslabs/orchard/internal/controller/notifier"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestNotifier(t *testing.T) {
+	ctx := context.Background()
+
+	notifier := notifier.NewNotifier()
+
+	var topic = uuid.New().String()
+
+	msgCh, cancel := notifier.Register(context.Background(), topic)
+	defer cancel()
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	go func() {
+		require.NoError(t, notifier.Notify(ctx, topic, nil))
+
+		time.Sleep(time.Second)
+
+		require.NoError(t, notifier.Notify(ctx, topic, nil))
+
+		wg.Done()
+	}()
+
+	fmt.Println("waiting for the message...")
+
+	<-msgCh
+
+	fmt.Println("received first message")
+
+	<-msgCh
+
+	fmt.Println("received second message")
+
+	wg.Wait()
+}