Make channels more specific

cmd/icingadb/main.go

@@ -42,7 +42,7 @@ func main() {
 	s := icingadb.NewSync(db, rc, logger)
 
 	// For temporary exit after sync
-	done := make(chan interface{}, 0)
+	done := make(chan struct{}, 0)
 
 	// Main loop
 	for {

pkg/icingadb/ha.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"database/sql"
 	"encoding/hex"
-	"errors"
 	"github.com/google/uuid"
 	v1 "github.com/icinga/icingadb/pkg/icingadb/v1"
 	"github.com/icinga/icingadb/pkg/icingaredis"
@@ -26,9 +25,9 @@ type HA struct {
 	heartbeat   *icingaredis.Heartbeat
 	logger      *zap.SugaredLogger
 	responsible bool
-	handover    chan interface{}
-	takeover    chan interface{}
-	done        chan interface{}
+	handover    chan struct{}
+	takeover    chan struct{}
+	done        chan struct{}
 	mu          *sync.Mutex
 	err         error
 	errOnce     sync.Once
@@ -46,9 +45,9 @@ func NewHA(ctx context.Context, db *DB, heartbeat *icingaredis.Heartbeat, logger
 		db:         db,
 		heartbeat:  heartbeat,
 		logger:     logger,
-		handover:   make(chan interface{}),
-		takeover:   make(chan interface{}),
-		done:       make(chan interface{}),
+		handover:   make(chan struct{}),
+		takeover:   make(chan struct{}),
+		done:       make(chan struct{}),
 		mu:         &sync.Mutex{},
 	}
 
@@ -67,7 +66,7 @@ func (h *HA) Close() error {
 	return h.Err()
 }
 
-func (h *HA) Done() <-chan interface{} {
+func (h *HA) Done() <-chan struct{} {
 	return h.done
 }
 
@@ -78,11 +77,11 @@ func (h *HA) Err() error {
 	return h.err
 }
 
-func (h *HA) Handover() chan interface{} {
+func (h *HA) Handover() chan struct{} {
 	return h.handover
 }
 
-func (h *HA) Takeover() chan interface{} {
+func (h *HA) Takeover() chan struct{} {
 	return h.takeover
 }
 
@@ -104,16 +103,12 @@ func (h *HA) controller() {
 
 	for {
 		select {
-		case b, ok := <-h.heartbeat.Beat():
+		case m, ok := <-h.heartbeat.Beat():
 			if !ok {
 				// Beat channel closed.
 				return
 			}
 			now := time.Now()
-			m, ok := b.(icingaredisv1.StatsMessage)
-			if !ok {
-				h.abort(errors.New("bad message"))
-			}
 			t, err := m.Time()
 			if err != nil {
 				h.abort(err)

pkg/icingaredis/heartbeat.go

@@ -19,9 +19,9 @@ type Heartbeat struct {
 	client *Client
 	logger *zap.SugaredLogger
 	active bool
-	beat   chan interface{}
-	lost   chan interface{}
-	done   chan interface{}
+	beat   chan v1.StatsMessage
+	lost   chan struct{}
+	done   chan struct{}
 	mu     *sync.Mutex
 	err    error
 }
@@ -34,9 +34,9 @@ func NewHeartbeat(ctx context.Context, client *Client, logger *zap.SugaredLogger
 		cancel: cancel,
 		client: client,
 		logger: logger,
-		beat:   make(chan interface{}),
-		lost:   make(chan interface{}),
-		done:   make(chan interface{}),
+		beat:   make(chan v1.StatsMessage),
+		lost:   make(chan struct{}),
+		done:   make(chan struct{}),
 		mu:     &sync.Mutex{},
 	}
 
@@ -55,7 +55,7 @@ func (h Heartbeat) Close() error {
 	return h.Err()
 }
 
-func (h Heartbeat) Done() <-chan interface{} {
+func (h Heartbeat) Done() <-chan struct{} {
 	return h.done
 }
 
@@ -66,17 +66,17 @@ func (h Heartbeat) Err() error {
 	return h.err
 }
 
-func (h Heartbeat) Beat() <-chan interface{} {
+func (h Heartbeat) Beat() <-chan v1.StatsMessage {
 	return h.beat
 }
 
-func (h Heartbeat) Lost() <-chan interface{} {
+func (h Heartbeat) Lost() <-chan struct{} {
 	return h.lost
 }
 
 // controller loop.
 func (h Heartbeat) controller() {
-	messages := make(chan interface{})
+	messages := make(chan v1.StatsMessage)
 	defer close(messages)
 
 	g, ctx := errgroup.WithContext(h.ctx)
@@ -95,7 +95,7 @@ func (h Heartbeat) controller() {
 			}
 
 			select {
-			case messages <- v1.StatsMessage(streams[0].Messages[0].Values):
+			case messages <- streams[0].Messages[0].Values:
 			case <-ctx.Done():
 				return ctx.Err()
 			}