119 lines
2.7 KiB
Go
119 lines
2.7 KiB
Go
/*
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Copyright 2021 The Dapr Authors
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package inmemory
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import (
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"context"
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"errors"
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"sync"
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"sync/atomic"
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"time"
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"github.com/dapr/components-contrib/internal/eventbus"
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"github.com/dapr/components-contrib/metadata"
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"github.com/dapr/components-contrib/pubsub"
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"github.com/dapr/kit/logger"
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)
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type bus struct {
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bus eventbus.Bus
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log logger.Logger
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closed atomic.Bool
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closeCh chan struct{}
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wg sync.WaitGroup
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}
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func New(logger logger.Logger) pubsub.PubSub {
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return &bus{
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log: logger,
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closeCh: make(chan struct{}),
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}
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}
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func (a *bus) Close() error {
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if a.closed.CompareAndSwap(false, true) {
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close(a.closeCh)
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}
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a.wg.Wait()
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return nil
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}
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func (a *bus) Features() []pubsub.Feature {
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return []pubsub.Feature{pubsub.FeatureSubscribeWildcards}
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}
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func (a *bus) Init(_ context.Context, metadata pubsub.Metadata) error {
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a.bus = eventbus.New(true)
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return nil
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}
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func (a *bus) Publish(_ context.Context, req *pubsub.PublishRequest) error {
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if a.closed.Load() {
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return errors.New("component is closed")
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}
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a.bus.Publish(req.Topic, req.Data)
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return nil
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}
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func (a *bus) Subscribe(ctx context.Context, req pubsub.SubscribeRequest, handler pubsub.Handler) error {
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if a.closed.Load() {
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return errors.New("component is closed")
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}
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// For this component we allow built-in retries because it is backed by memory
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retryHandler := func(data []byte) {
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for i := 0; i < 10; i++ {
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handleErr := handler(ctx, &pubsub.NewMessage{Data: data, Topic: req.Topic, Metadata: req.Metadata})
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if handleErr == nil {
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break
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}
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a.log.Error(handleErr)
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select {
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case <-time.After(100 * time.Millisecond):
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// Nop
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case <-ctx.Done():
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return
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}
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}
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}
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err := a.bus.SubscribeAsync(req.Topic, retryHandler, true)
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if err != nil {
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return err
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}
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// Unsubscribe when context is done
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a.wg.Add(1)
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go func() {
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defer a.wg.Done()
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select {
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case <-ctx.Done():
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case <-a.closeCh:
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}
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err := a.bus.Unsubscribe(req.Topic, retryHandler)
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if err != nil {
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a.log.Errorf("error while unsubscribing from topic %s: %v", req.Topic, err)
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}
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}()
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return nil
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}
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// GetComponentMetadata returns the metadata of the component.
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func (a *bus) GetComponentMetadata() (metadataInfo metadata.MetadataMap) {
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return
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}
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