grpc-go/xds/internal/testutils/resource_watcher.go

84 lines
2.5 KiB
Go

/*
*
* 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/xds/internal/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),
}
}