Mainflux.mainflux/coap/adapter.go

101 lines
2.8 KiB
Go

// Copyright (c) Mainflux
// SPDX-License-Identifier: Apache-2.0
// Package coap contains the domain concept definitions needed to support
// Mainflux CoAP adapter service functionality. All constant values are taken
// from RFC, and could be adjusted based on specific use case.
package coap
import (
"context"
"fmt"
"sync"
"github.com/mainflux/mainflux/pkg/errors"
"github.com/mainflux/mainflux"
"github.com/mainflux/mainflux/pkg/messaging"
)
const chansPrefix = "channels"
// ErrUnsubscribe indicates an error to unsubscribe
var ErrUnsubscribe = errors.New("unable to unsubscribe")
// Service specifies CoAP service API.
type Service interface {
// Publish Messssage
Publish(ctx context.Context, key string, msg messaging.Message) error
// Subscribes to channel with specified id, subtopic and adds subscription to
// service map of subscriptions under given ID.
Subscribe(ctx context.Context, key, chanID, subtopic string, c Client) error
// Unsubscribe method is used to stop observing resource.
Unsubscribe(ctx context.Context, key, chanID, subptopic, token string) error
}
var _ Service = (*adapterService)(nil)
// Observers is a map of maps,
type adapterService struct {
auth mainflux.ThingsServiceClient
pubsub messaging.PubSub
obsLock sync.Mutex
}
// New instantiates the CoAP adapter implementation.
func New(auth mainflux.ThingsServiceClient, pubsub messaging.PubSub) Service {
as := &adapterService{
auth: auth,
pubsub: pubsub,
obsLock: sync.Mutex{},
}
return as
}
func (svc *adapterService) Publish(ctx context.Context, key string, msg messaging.Message) error {
ar := &mainflux.AccessByKeyReq{
Token: key,
ChanID: msg.Channel,
}
thid, err := svc.auth.CanAccessByKey(ctx, ar)
if err != nil {
return errors.Wrap(errors.ErrAuthorization, err)
}
msg.Publisher = thid.GetValue()
return svc.pubsub.Publish(msg.Channel, msg)
}
func (svc *adapterService) Subscribe(ctx context.Context, key, chanID, subtopic string, c Client) error {
ar := &mainflux.AccessByKeyReq{
Token: key,
ChanID: chanID,
}
if _, err := svc.auth.CanAccessByKey(ctx, ar); err != nil {
return errors.Wrap(errors.ErrAuthorization, err)
}
subject := fmt.Sprintf("%s.%s", chansPrefix, chanID)
if subtopic != "" {
subject = fmt.Sprintf("%s.%s", subject, subtopic)
}
return svc.pubsub.Subscribe(c.Token(), subject, c)
}
func (svc *adapterService) Unsubscribe(ctx context.Context, key, chanID, subtopic, token string) error {
ar := &mainflux.AccessByKeyReq{
Token: key,
ChanID: chanID,
}
if _, err := svc.auth.CanAccessByKey(ctx, ar); err != nil {
return errors.Wrap(errors.ErrAuthorization, err)
}
subject := fmt.Sprintf("%s.%s", chansPrefix, chanID)
if subtopic != "" {
subject = fmt.Sprintf("%s.%s", subject, subtopic)
}
return svc.pubsub.Unsubscribe(token, subject)
}