snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

internal/balancer/nop/nop.go

@@ -0,0 +1,65 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package nop implements a balancer with all of its balancer operations as
+// no-ops, other than returning a Transient Failure Picker on a Client Conn
+// update.
+package nop
+
+import (
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/connectivity"
+)
+
+// bal is a balancer with all of its balancer operations as no-ops, other than
+// returning a Transient Failure Picker on a Client Conn update.
+type bal struct {
+	cc  balancer.ClientConn
+	err error
+}
+
+// NewBalancer returns a no-op balancer.
+func NewBalancer(cc balancer.ClientConn, err error) balancer.Balancer {
+	return &bal{
+		cc:  cc,
+		err: err,
+	}
+}
+
+// UpdateClientConnState updates the bal's Client Conn with an Error Picker
+// and a Connectivity State of TRANSIENT_FAILURE.
+func (b *bal) UpdateClientConnState(_ balancer.ClientConnState) error {
+	b.cc.UpdateState(balancer.State{
+		Picker:            base.NewErrPicker(b.err),
+		ConnectivityState: connectivity.TransientFailure,
+	})
+	return nil
+}
+
+// ResolverError is a no-op.
+func (b *bal) ResolverError(_ error) {}
+
+// UpdateSubConnState is a no-op.
+func (b *bal) UpdateSubConnState(_ balancer.SubConn, _ balancer.SubConnState) {}
+
+// Close is a no-op.
+func (b *bal) Close() {}
+
+// ExitIdle is a no-op.
+func (b *bal) ExitIdle() {}