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

internal/xds/testutils/resource_watcher.go

@@ -0,0 +1,83 @@
+/*
+ *
+ * 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 testutils
+
+import "google.golang.org/grpc/internal/xds/xdsclient/xdsresource"
+
+// TestResourceWatcher implements the xdsresource.ResourceWatcher interface,
+// used to receive updates on watches registered with the xDS client, when using
+// the resource-type agnostic WatchResource API.
+//
+// Tests can use the channels provided by this type to get access to updates and
+// errors sent by the xDS client.
+type TestResourceWatcher struct {
+	// UpdateCh is the channel on which xDS client updates are delivered.
+	UpdateCh chan *xdsresource.ResourceData
+	// AmbientErrorCh is the channel on which ambient errors from the xDS
+	// client are delivered.
+	AmbientErrorCh chan error
+	// ResourceErrorCh is the channel on which resource errors from the xDS
+	// client are delivered.
+	ResourceErrorCh chan struct{}
+}
+
+// ResourceChanged is invoked by the xDS client to report the latest update.
+func (w *TestResourceWatcher) ResourceChanged(data xdsresource.ResourceData, onDone func()) {
+	defer onDone()
+	select {
+	case <-w.UpdateCh:
+	default:
+	}
+	w.UpdateCh <- &data
+
+}
+
+// ResourceError is invoked by the xDS client to report the latest error to
+// stop watching the resource.
+func (w *TestResourceWatcher) ResourceError(err error, onDone func()) {
+	defer onDone()
+	select {
+	case <-w.ResourceErrorCh:
+	case <-w.AmbientErrorCh:
+	default:
+	}
+	w.AmbientErrorCh <- err
+	w.ResourceErrorCh <- struct{}{}
+}
+
+// AmbientError is invoked by the xDS client to report the latest ambient
+// error.
+func (w *TestResourceWatcher) AmbientError(err error, onDone func()) {
+	defer onDone()
+	select {
+	case <-w.AmbientErrorCh:
+	default:
+	}
+	w.AmbientErrorCh <- err
+}
+
+// NewTestResourceWatcher returns a TestResourceWatcher to watch for resources
+// via the xDS client.
+func NewTestResourceWatcher() *TestResourceWatcher {
+	return &TestResourceWatcher{
+		UpdateCh:        make(chan *xdsresource.ResourceData, 1),
+		AmbientErrorCh:  make(chan error, 1),
+		ResourceErrorCh: make(chan struct{}, 1),
+	}
+}