/
amqp.go
129 lines (114 loc) · 3.21 KB
/
amqp.go
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// Copyright © 2017 The Things Network
// Use of this source code is governed by the MIT license that can be found in the LICENSE file.
package handler
import (
"sync"
ttnlog "github.com/TheThingsNetwork/go-utils/log"
"github.com/TheThingsNetwork/ttn/amqp"
"github.com/TheThingsNetwork/ttn/core/types"
)
// AMQPBufferSize indicates the size for uplink channel buffers
var AMQPBufferSize = 10
func (h *handler) assertAMQPExchange() error {
ch, err := h.amqpClient.(*amqp.DefaultClient).GetChannel()
if err != nil {
return err
}
err = ch.ExchangeDeclarePassive(h.amqpExchange, "topic", true, false, false, false, nil)
if err != nil {
h.Ctx.Warnf("Could not assert presence of AMQP Exchange %s, trying to create...", h.amqpExchange)
ch, err := h.amqpClient.(*amqp.DefaultClient).GetChannel()
if err != nil {
return err
}
err = ch.ExchangeDeclare(h.amqpExchange, "topic", true, false, false, false, nil)
if err != nil {
h.Ctx.Errorf("Could not create AMQP Exchange %s.", h.amqpExchange)
return err
}
h.Ctx.Infof("Created AMQP Exchange %s", h.amqpExchange)
}
return nil
}
func (h *handler) HandleAMQP(username, password, host, exchange, downlinkQueue string) error {
h.amqpClient = amqp.NewClient(h.Ctx, username, password, host)
err := h.amqpClient.Connect()
if err != nil {
return err
}
defer func() {
if err != nil {
h.amqpClient.Disconnect()
}
}()
if err := h.assertAMQPExchange(); err != nil {
return err
}
h.amqpUp = make(chan *types.UplinkMessage, AMQPBufferSize)
h.amqpEvent = make(chan *types.DeviceEvent, AMQPBufferSize)
subscriber := h.amqpClient.NewSubscriber(h.amqpExchange, downlinkQueue, downlinkQueue != "", downlinkQueue == "")
err = subscriber.Open()
if err != nil {
return err
}
defer func() {
if err != nil {
subscriber.Close()
}
}()
err = subscriber.SubscribeDownlink(func(_ amqp.Subscriber, _, _ string, req types.DownlinkMessage) {
h.EnqueueDownlink(&req)
})
if err != nil {
return err
}
ctx := h.Ctx.WithField("Protocol", "AMQP")
publisher := h.amqpClient.NewPublisher(h.amqpExchange)
err = publisher.Open()
if err != nil {
ctx.WithError(err).Error("Could not open publisher channel")
return err
}
var pubWait sync.WaitGroup
pubWait.Add(2)
defer func() {
go func() {
pubWait.Wait()
publisher.Close()
}()
}()
go func() {
defer pubWait.Done()
for up := range h.amqpUp {
ctx := ctx.WithFields(ttnlog.Fields{
"DevID": up.DevID,
"AppID": up.AppID,
})
ctx.Debug("Publish Uplink")
if err := publisher.PublishUplink(*up); err != nil {
ctx.WithError(err).Warn("Could not publish Uplink")
}
}
}()
go func() {
defer pubWait.Done()
for event := range h.amqpEvent {
ctx := ctx.WithFields(ttnlog.Fields{
"DevID": event.DevID,
"AppID": event.AppID,
"Event": event.Event,
})
ctx.Debug("Publish Event")
if event.DevID == "" {
if err := publisher.PublishAppEvent(event.AppID, event.Event, event.Data); err != nil {
ctx.WithError(err).Warn("Could not publish App Event")
}
} else {
if err := publisher.PublishDeviceEvent(event.AppID, event.DevID, event.Event, event.Data); err != nil {
ctx.WithError(err).Warn("Could not publish Device Event")
}
}
}
}()
return nil
}