Mainflux.mainflux/twins/service.go

444 lines
11 KiB
Go

// Copyright (c) Mainflux
// SPDX-License-Identifier: Apache-2.0
package twins
import (
"context"
"encoding/json"
"fmt"
"math"
"time"
"github.com/mainflux/mainflux/logger"
"github.com/mainflux/mainflux/pkg/errors"
"github.com/mainflux/mainflux/pkg/messaging"
"github.com/mainflux/mainflux"
"github.com/mainflux/senml"
)
const publisher = "twins"
var (
// ErrMalformedEntity indicates malformed entity specification (e.g.
// invalid username or password).
ErrMalformedEntity = errors.New("malformed entity specification")
// ErrUnauthorizedAccess indicates missing or invalid credentials provided
// when accessing a protected resource.
ErrUnauthorizedAccess = errors.New("missing or invalid credentials provided")
// ErrNotFound indicates a non-existent entity request.
ErrNotFound = errors.New("non-existent entity")
// ErrConflict indicates that entity already exists.
ErrConflict = errors.New("entity already exists")
)
// Service specifies an API that must be fullfiled by the domain service
// implementation, and all of its decorators (e.g. logging & metrics).
type Service interface {
// AddTwin adds new twin related to user identified by the provided key.
AddTwin(ctx context.Context, token string, twin Twin, def Definition) (tw Twin, err error)
// UpdateTwin updates twin identified by the provided Twin that
// belongs to the user identified by the provided key.
UpdateTwin(ctx context.Context, token string, twin Twin, def Definition) (err error)
// ViewTwin retrieves data about twin with the provided
// ID belonging to the user identified by the provided key.
ViewTwin(ctx context.Context, token, twinID string) (tw Twin, err error)
// RemoveTwin removes the twin identified with the provided ID, that
// belongs to the user identified by the provided key.
RemoveTwin(ctx context.Context, token, twinID string) (err error)
// ListTwins retrieves data about subset of twins that belongs to the
// user identified by the provided key.
ListTwins(ctx context.Context, token string, offset uint64, limit uint64, name string, metadata Metadata) (Page, error)
// ListStates retrieves data about subset of states that belongs to the
// twin identified by the id.
ListStates(ctx context.Context, token string, offset uint64, limit uint64, twinID string) (StatesPage, error)
// SaveStates persists states into database
SaveStates(msg *messaging.Message) error
}
const (
noop = iota
update
save
millisec = 1e6
nanosec = 1e9
SubtopicWildcard = ">"
)
var crudOp = map[string]string{
"createSucc": "create.success",
"createFail": "create.failure",
"updateSucc": "update.success",
"updateFail": "update.failure",
"getSucc": "get.success",
"getFail": "get.failure",
"removeSucc": "remove.success",
"removeFail": "remove.failure",
"stateSucc": "save.success",
"stateFail": "save.failure",
}
type twinsService struct {
publisher messaging.Publisher
auth mainflux.AuthNServiceClient
twins TwinRepository
states StateRepository
uuidProvider mainflux.UUIDProvider
channelID string
twinCache TwinCache
logger logger.Logger
}
var _ Service = (*twinsService)(nil)
// New instantiates the twins service implementation.
func New(publisher messaging.Publisher, auth mainflux.AuthNServiceClient, twins TwinRepository, tcache TwinCache, sr StateRepository, idp mainflux.UUIDProvider, chann string, logger logger.Logger) Service {
return &twinsService{
publisher: publisher,
auth: auth,
twins: twins,
twinCache: tcache,
states: sr,
uuidProvider: idp,
channelID: chann,
logger: logger,
}
}
func (ts *twinsService) AddTwin(ctx context.Context, token string, twin Twin, def Definition) (tw Twin, err error) {
var id string
var b []byte
defer ts.publish(&id, &err, crudOp["createSucc"], crudOp["createFail"], &b)
res, err := ts.auth.Identify(ctx, &mainflux.Token{Value: token})
if err != nil {
return Twin{}, ErrUnauthorizedAccess
}
twin.ID, err = ts.uuidProvider.ID()
if err != nil {
return Twin{}, err
}
twin.Owner = res.GetValue()
t := time.Now()
twin.Created = t
twin.Updated = t
if def.Attributes == nil {
def.Attributes = []Attribute{}
}
if def.Delta == 0 {
def.Delta = millisec
}
def.Created = time.Now()
def.ID = 0
twin.Definitions = append(twin.Definitions, def)
twin.Revision = 0
if _, err = ts.twins.Save(ctx, twin); err != nil {
return Twin{}, err
}
id = twin.ID
b, err = json.Marshal(twin)
return twin, ts.twinCache.Save(ctx, twin)
}
func (ts *twinsService) UpdateTwin(ctx context.Context, token string, twin Twin, def Definition) (err error) {
var b []byte
var id string
defer ts.publish(&id, &err, crudOp["updateSucc"], crudOp["updateFail"], &b)
_, err = ts.auth.Identify(ctx, &mainflux.Token{Value: token})
if err != nil {
return ErrUnauthorizedAccess
}
tw, err := ts.twins.RetrieveByID(ctx, twin.ID)
if err != nil {
return err
}
revision := false
if twin.Name != "" {
revision = true
tw.Name = twin.Name
}
if len(def.Attributes) > 0 {
revision = true
def.Created = time.Now()
def.ID = tw.Definitions[len(tw.Definitions)-1].ID + 1
tw.Definitions = append(tw.Definitions, def)
}
if len(twin.Metadata) > 0 {
revision = true
tw.Metadata = twin.Metadata
}
if !revision {
return ErrMalformedEntity
}
tw.Updated = time.Now()
tw.Revision++
if err := ts.twins.Update(ctx, tw); err != nil {
return err
}
id = twin.ID
b, err = json.Marshal(tw)
return ts.twinCache.Update(ctx, twin)
}
func (ts *twinsService) ViewTwin(ctx context.Context, token, twinID string) (tw Twin, err error) {
var b []byte
defer ts.publish(&twinID, &err, crudOp["getSucc"], crudOp["getFail"], &b)
_, err = ts.auth.Identify(ctx, &mainflux.Token{Value: token})
if err != nil {
return Twin{}, ErrUnauthorizedAccess
}
twin, err := ts.twins.RetrieveByID(ctx, twinID)
if err != nil {
return Twin{}, err
}
b, err = json.Marshal(twin)
return twin, nil
}
func (ts *twinsService) RemoveTwin(ctx context.Context, token, twinID string) (err error) {
var b []byte
defer ts.publish(&twinID, &err, crudOp["removeSucc"], crudOp["removeFail"], &b)
_, err = ts.auth.Identify(ctx, &mainflux.Token{Value: token})
if err != nil {
return ErrUnauthorizedAccess
}
if err := ts.twins.Remove(ctx, twinID); err != nil {
return err
}
return ts.twinCache.Remove(ctx, twinID)
}
func (ts *twinsService) ListTwins(ctx context.Context, token string, offset uint64, limit uint64, name string, metadata Metadata) (Page, error) {
res, err := ts.auth.Identify(ctx, &mainflux.Token{Value: token})
if err != nil {
return Page{}, ErrUnauthorizedAccess
}
return ts.twins.RetrieveAll(ctx, res.GetValue(), offset, limit, name, metadata)
}
func (ts *twinsService) ListStates(ctx context.Context, token string, offset uint64, limit uint64, twinID string) (StatesPage, error) {
_, err := ts.auth.Identify(ctx, &mainflux.Token{Value: token})
if err != nil {
return StatesPage{}, ErrUnauthorizedAccess
}
return ts.states.RetrieveAll(ctx, offset, limit, twinID)
}
func (ts *twinsService) SaveStates(msg *messaging.Message) error {
var ids []string
ctx := context.TODO()
channel, subtopic := msg.Channel, msg.Subtopic
ids, err := ts.twinCache.IDs(ctx, channel, subtopic)
if err != nil {
return err
}
if len(ids) < 1 {
ids, err = ts.twins.RetrieveByAttribute(ctx, channel, subtopic)
if err != nil {
return err
}
if len(ids) < 1 {
return nil
}
if err := ts.twinCache.SaveIDs(ctx, channel, subtopic, ids); err != nil {
return err
}
}
for _, id := range ids {
if err := ts.saveState(msg, id); err != nil {
return err
}
}
return nil
}
func (ts *twinsService) saveState(msg *messaging.Message, twinID string) error {
var b []byte
var err error
defer ts.publish(&twinID, &err, crudOp["stateSucc"], crudOp["stateFail"], &b)
ctx := context.TODO()
tw, err := ts.twins.RetrieveByID(ctx, twinID)
if err != nil {
return fmt.Errorf("Retrieving twin for %s failed: %s", msg.Publisher, err)
}
var recs []senml.Record
if err := json.Unmarshal(msg.Payload, &recs); err != nil {
return fmt.Errorf("Unmarshal payload for %s failed: %s", msg.Publisher, err)
}
st, err := ts.states.RetrieveLast(ctx, tw.ID)
if err != nil {
return fmt.Errorf("Retrieve last state for %s failed: %s", msg.Publisher, err)
}
for _, rec := range recs {
action := ts.prepareState(&st, &tw, rec, msg)
switch action {
case noop:
return nil
case update:
if err := ts.states.Update(ctx, st); err != nil {
return fmt.Errorf("Update state for %s failed: %s", msg.Publisher, err)
}
case save:
if err := ts.states.Save(ctx, st); err != nil {
return fmt.Errorf("Save state for %s failed: %s", msg.Publisher, err)
}
}
}
twinID = msg.Publisher
b = msg.Payload
return nil
}
func (ts *twinsService) prepareState(st *State, tw *Twin, rec senml.Record, msg *messaging.Message) int {
def := tw.Definitions[len(tw.Definitions)-1]
st.TwinID = tw.ID
st.Definition = def.ID
if st.Payload == nil {
st.Payload = make(map[string]interface{})
st.ID = -1 // state is incremented on save -> zero-based index
} else {
for k := range st.Payload {
idx := findAttribute(k, def.Attributes)
if idx < 0 || !def.Attributes[idx].PersistState {
delete(st.Payload, k)
}
}
}
recSec := rec.BaseTime + rec.Time
recNano := recSec * nanosec
sec, dec := math.Modf(recSec)
recTime := time.Unix(int64(sec), int64(dec*nanosec))
action := noop
for _, attr := range def.Attributes {
if !attr.PersistState {
continue
}
if attr.Channel == msg.Channel && (attr.Subtopic == SubtopicWildcard || attr.Subtopic == msg.Subtopic) {
action = update
delta := math.Abs(float64(st.Created.UnixNano()) - recNano)
if recNano == 0 || delta > float64(def.Delta) {
action = save
st.ID++
st.Created = time.Now()
if recNano != 0 {
st.Created = recTime
}
}
val := findValue(rec)
st.Payload[attr.Name] = val
break
}
}
return action
}
func findValue(rec senml.Record) interface{} {
if rec.Value != nil {
return rec.Value
}
if rec.StringValue != nil {
return rec.StringValue
}
if rec.DataValue != nil {
return rec.DataValue
}
if rec.BoolValue != nil {
return rec.BoolValue
}
if rec.Sum != nil {
return rec.Sum
}
return nil
}
func findAttribute(name string, attrs []Attribute) (idx int) {
for idx, attr := range attrs {
if attr.Name == name {
return idx
}
}
return -1
}
func (ts *twinsService) publish(twinID *string, err *error, succOp, failOp string, payload *[]byte) {
if ts.channelID == "" {
return
}
op := succOp
if *err != nil {
op = failOp
esb := []byte((*err).Error())
payload = &esb
}
pl := *payload
if pl == nil {
pl = []byte(fmt.Sprintf("{\"deleted\":\"%s\"}", *twinID))
}
msg := messaging.Message{
Channel: ts.channelID,
Subtopic: op,
Payload: pl,
Publisher: publisher,
Created: time.Now().UnixNano(),
}
if err := ts.publisher.Publish(msg.Channel, msg); err != nil {
ts.logger.Warn(fmt.Sprintf("Failed to publish notification on NATS: %s", err))
}
}