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// Package service provides the broker service client
package service
import (
"context"
"fmt"
"time"
pb "github.com/unistack-org/micro-broker-service/v3/proto"
"github.com/unistack-org/micro/v3/broker"
"github.com/unistack-org/micro/v3/client"
"github.com/unistack-org/micro/v3/logger"
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)
type serviceBroker struct {
addrs []string
service string
client pb.BrokerService
opts broker.Options
}
func (b *serviceBroker) Address() string {
return b.addrs[0]
}
func (b *serviceBroker) Connect(ctx context.Context) error {
return nil
}
func (b *serviceBroker) Disconnect(ctx context.Context) error {
return nil
}
func (b *serviceBroker) Init(opts ...broker.Option) error {
for _, o := range opts {
o(&b.opts)
}
var cli client.Client
if b.opts.Context != nil {
if v, ok := b.opts.Context.Value(clientKey{}).(client.Client); ok && v != nil {
cli = v
}
if v, ok := b.opts.Context.Value(serviceKey{}).(string); ok && v != "" {
b.service = v
}
}
if b.service == "" {
return fmt.Errorf("missing Service option")
}
if cli == nil {
return fmt.Errorf("missing Client option")
}
b.client = pb.NewBrokerService(b.service, cli)
return nil
}
func (b *serviceBroker) Options() broker.Options {
return b.opts
}
func (b *serviceBroker) Publish(ctx context.Context, topic string, msg *broker.Message, opts ...broker.PublishOption) error {
if logger.V(logger.TraceLevel) {
logger.Tracef(ctx, "Publishing to topic %s broker %v", topic, b.addrs)
}
_, err := b.client.Publish(ctx, &pb.PublishRequest{
Topic: topic,
Message: &pb.Message{
Header: msg.Header,
Body: msg.Body,
},
}, client.WithAddress(b.addrs...))
return err
}
func (b *serviceBroker) Subscribe(ctx context.Context, topic string, handler broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
options := broker.NewSubscribeOptions(opts...)
if logger.V(logger.TraceLevel) {
logger.Tracef(ctx, "Subscribing to topic %s group %s broker %v", topic, options.Group, b.addrs)
}
stream, err := b.client.Subscribe(ctx, &pb.SubscribeRequest{
Topic: topic,
Group: options.Group,
}, client.WithAddress(b.addrs...), client.WithRequestTimeout(time.Hour))
if err != nil {
return nil, err
}
sub := &serviceSub{
topic: topic,
group: options.Group,
handler: handler,
stream: stream,
closed: make(chan bool),
options: options,
}
go func() {
for {
select {
case <-sub.closed:
if logger.V(logger.TraceLevel) {
logger.Tracef(ctx, "Unsubscribed from topic %s", topic)
}
return
default:
if logger.V(logger.TraceLevel) {
// run the subscriber
logger.Tracef(ctx, "Streaming from broker %v to topic [%s] group [%s]", b.addrs, topic, options.Group)
}
if err := sub.run(ctx); err != nil {
if logger.V(logger.TraceLevel) {
logger.Tracef(ctx, "Resubscribing to topic %s broker %v", topic, b.addrs)
}
stream, err := b.client.Subscribe(ctx, &pb.SubscribeRequest{
Topic: topic,
Group: options.Group,
}, client.WithAddress(b.addrs...), client.WithRequestTimeout(time.Hour))
if err != nil {
if logger.V(logger.TraceLevel) {
logger.Tracef(ctx, "Failed to resubscribe to topic %s: %v", topic, err)
}
time.Sleep(time.Second)
continue
}
// new stream
sub.stream = stream
}
}
}
}()
return sub, nil
}
func (b *serviceBroker) String() string {
return "service"
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}
func (b *serviceBroker) Name() string {
return b.opts.Name
}
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func NewBroker(opts ...broker.Option) broker.Broker {
options := broker.NewOptions(opts...)
addrs := options.Addrs
if len(addrs) == 0 {
addrs = []string{"127.0.0.1:8001"}
}
return &serviceBroker{
addrs: addrs,
opts: options,
}
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}