forked from knative/eventing
/
dispatcher.go
97 lines (81 loc) · 2.57 KB
/
dispatcher.go
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/*
Copyright 2019 The Knative 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 inmemorychannel
import (
"context"
"errors"
"time"
cloudevents "github.com/cloudevents/sdk-go"
"go.uber.org/zap"
"knative.dev/eventing/pkg/channel/multichannelfanout"
"knative.dev/eventing/pkg/channel/swappable"
"knative.dev/eventing/pkg/kncloudevents"
)
type Dispatcher interface {
UpdateConfig(config *multichannelfanout.Config) error
}
type InMemoryDispatcher struct {
handler *swappable.Handler
ceClient cloudevents.Client
writeTimeout time.Duration
logger *zap.Logger
}
type InMemoryDispatcherArgs struct {
Port int
ReadTimeout time.Duration
WriteTimeout time.Duration
Handler *swappable.Handler
Logger *zap.Logger
}
func (d *InMemoryDispatcher) UpdateConfig(config *multichannelfanout.Config) error {
return d.handler.UpdateConfig(config)
}
// Start starts the inmemory dispatcher's message processing.
// This is a blocking call.
func (d *InMemoryDispatcher) Start(ctx context.Context) error {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
errCh := make(chan error, 1)
go func() {
errCh <- d.ceClient.StartReceiver(ctx, d.handler.ServeHTTP)
}()
// Stop either if the receiver stops (sending to errCh) or if the context Done channel is closed.
select {
case err := <-errCh:
return err
case <-ctx.Done():
break
}
// Done channel has been closed, we need to gracefully shutdown d.ceClient. The cancel() method will start its
// shutdown, if it hasn't finished in a reasonable amount of time, just return an error.
cancel()
select {
case err := <-errCh:
return err
case <-time.After(d.writeTimeout):
return errors.New("timeout shutting down ceClient")
}
}
func NewDispatcher(args *InMemoryDispatcherArgs) *InMemoryDispatcher {
// TODO set read and write timeouts and port?
ceClient, err := kncloudevents.NewDefaultClient()
if err != nil {
args.Logger.Fatal("failed to create cloudevents client", zap.Error(err))
}
dispatcher := &InMemoryDispatcher{
handler: args.Handler,
ceClient: ceClient,
logger: args.Logger,
}
return dispatcher
}