SearchValue: simplify error handling

routing.go

@@ -107,6 +107,7 @@ func (dht *IpfsDHT) PutValue(ctx context.Context, key string, value []byte, opts
 type RecvdVal struct {
 	Val  []byte
 	From peer.ID
+	Err  error
 }
 
 // GetValue searches for the value corresponding to given Key.
@@ -123,29 +124,27 @@ func (dht *IpfsDHT) GetValue(ctx context.Context, key string, opts ...ropts.Opti
 	responses, errCh := dht.SearchValue(ctx, key, opts...)
 	var best []byte
 
-	loop:
 	for {
 		select {
 		case r, ok := <-responses:
 			if !ok {
-				if errCh == nil {
-					break loop
-				}
 				responses = nil
-				continue
+				break
 			}
-			best = r
 
-		case err, ok := <- errCh:
+			best = r
+		case err, ok := <-errCh:
 			if !ok {
-				if responses == nil {
-					break loop
-				}
 				errCh = nil
-				continue
+				break
 			}
+
 			return nil, err
 		}
+
+		if errCh == nil && responses == nil {
+			break
+		}
 	}
 
 	if best == nil {
@@ -172,7 +171,7 @@ func (dht *IpfsDHT) SearchValue(ctx context.Context, key string, opts ...ropts.O
 		defer close(out)
 		defer close(outErr)
 
-		valCh, errCh := dht.GetValues(ctx, key, responsesNeeded)
+		valCh := dht.GetValues(ctx, key, responsesNeeded)
 		vals := make([]RecvdVal, 0, responsesNeeded)
 		best := -1
 
@@ -207,15 +206,15 @@ func (dht *IpfsDHT) SearchValue(ctx context.Context, key string, opts ...ropts.O
 			select {
 			case v, ok := <-valCh:
 				if !ok {
-					if errCh == nil {
-						return
-					}
 					// failed to find a good record
 					if best < 0 {
 						outErr <- routing.ErrNotFound
 					}
-					valCh = nil
-					continue
+					return
+				}
+				if v.Err != nil {
+					outErr <- v.Err
+					return
 				}
 
 				vals = append(vals, v)
@@ -240,16 +239,6 @@ func (dht *IpfsDHT) SearchValue(ctx context.Context, key string, opts ...ropts.O
 						out <- v.Val
 					}
 				}
-			case err, ok := <-errCh:
-				if !ok {
-					if valCh == nil {
-						return
-					}
-					errCh = nil
-					continue
-				}
-				outErr <- err
-				return
 			case <-ctx.Done():
 				outErr <- ctx.Err()
 				return
@@ -261,20 +250,22 @@ func (dht *IpfsDHT) SearchValue(ctx context.Context, key string, opts ...ropts.O
 }
 
 // GetValues gets nvals values corresponding to the given key.
-func (dht *IpfsDHT) GetValues(ctx context.Context, key string, nvals int) (<-chan RecvdVal, <-chan error) {
+func (dht *IpfsDHT) GetValues(ctx context.Context, key string, nvals int) <-chan RecvdVal {
 	eip := log.EventBegin(ctx, "GetValues")
 
-	vals := make(chan RecvdVal, nvals)
+	// alloc 1 to have for sync errors
+	vals := make(chan RecvdVal, 1)
 
-	done := func(err error) (<-chan RecvdVal, <-chan error) {
+	done := func(err error) <-chan RecvdVal {
 		defer close(vals)
 
 		eip.Append(loggableKey(key))
 		if err != nil {
 			eip.SetError(err)
+			vals <- RecvdVal{Err: err}
 		}
 		eip.Done()
-		return vals, wrapErr(err)
+		return vals
 	}
 
 	// If we have it local, don't bother doing an RPC!
@@ -365,9 +356,7 @@ func (dht *IpfsDHT) GetValues(ctx context.Context, key string, nvals int) (<-cha
 		return res, nil
 	})
 
-	errCh := make(chan error, 1)
 	go func() {
-		defer close(errCh)
 		reqCtx, cancel := context.WithTimeout(ctx, time.Minute)
 		defer cancel()
 
@@ -380,13 +369,10 @@ func (dht *IpfsDHT) GetValues(ctx context.Context, key string, nvals int) (<-cha
 		if got > 0 && (err == routing.ErrNotFound || reqCtx.Err() == context.DeadlineExceeded) {
 			err = nil
 		}
-		if err != nil {
-			errCh <- err
-		}
 		done(err)
 	}()
 
-	return vals, errCh
+	return vals
 }
 
 // Provider abstraction for indirect stores.