Mainflux.mainflux/twins/events/twins.go

129 lines
3.6 KiB
Go

// Copyright (c) Mainflux
// SPDX-License-Identifier: Apache-2.0
package events
import (
"context"
"fmt"
"github.com/go-redis/redis/v8"
"github.com/mainflux/mainflux/pkg/errors"
"github.com/mainflux/mainflux/twins"
)
const (
prefix = "twin"
)
var (
// ErrRedisTwinSave indicates error while saving Twin in redis cache.
ErrRedisTwinSave = errors.New("failed to save twin in redis cache")
// ErrRedisTwinUpdate indicates error while saving Twin in redis cache.
ErrRedisTwinUpdate = errors.New("failed to update twin in redis cache")
// ErrRedisTwinIDs indicates error while getting Twin IDs from redis cache.
ErrRedisTwinIDs = errors.New("failed to get twin id from redis cache")
// ErrRedisTwinRemove indicates error while removing Twin from redis cache.
ErrRedisTwinRemove = errors.New("failed to remove twin from redis cache")
)
var _ twins.TwinCache = (*twinCache)(nil)
type twinCache struct {
client *redis.Client
}
// NewTwinCache returns redis twin cache implementation.
func NewTwinCache(client *redis.Client) twins.TwinCache {
return &twinCache{
client: client,
}
}
func (tc *twinCache) Save(ctx context.Context, twin twins.Twin) error {
return tc.save(ctx, twin)
}
func (tc *twinCache) Update(ctx context.Context, twin twins.Twin) error {
if err := tc.remove(ctx, twin.ID); err != nil {
return errors.Wrap(ErrRedisTwinUpdate, err)
}
if err := tc.save(ctx, twin); err != nil {
return errors.Wrap(ErrRedisTwinUpdate, err)
}
return nil
}
func (tc *twinCache) SaveIDs(ctx context.Context, channel, subtopic string, ids []string) error {
for _, id := range ids {
if err := tc.client.SAdd(ctx, attrKey(channel, subtopic), id).Err(); err != nil {
return errors.Wrap(ErrRedisTwinSave, err)
}
if err := tc.client.SAdd(ctx, twinKey(id), attrKey(channel, subtopic)).Err(); err != nil {
return errors.Wrap(ErrRedisTwinSave, err)
}
}
return nil
}
func (tc *twinCache) IDs(ctx context.Context, channel, subtopic string) ([]string, error) {
ids, err := tc.client.SMembers(ctx, attrKey(channel, subtopic)).Result()
if err != nil {
return nil, errors.Wrap(ErrRedisTwinIDs, err)
}
idsWildcard, err := tc.client.SMembers(ctx, attrKey(channel, twins.SubtopicWildcard)).Result()
if err != nil {
return nil, errors.Wrap(ErrRedisTwinIDs, err)
}
ids = append(ids, idsWildcard...)
return ids, nil
}
func (tc *twinCache) Remove(ctx context.Context, twinID string) error {
return tc.remove(ctx, twinID)
}
func (tc *twinCache) save(ctx context.Context, twin twins.Twin) error {
if len(twin.Definitions) < 1 {
return nil
}
attributes := twin.Definitions[len(twin.Definitions)-1].Attributes
for _, attr := range attributes {
if err := tc.client.SAdd(ctx, attrKey(attr.Channel, attr.Subtopic), twin.ID).Err(); err != nil {
return errors.Wrap(ErrRedisTwinSave, err)
}
if err := tc.client.SAdd(ctx, twinKey(twin.ID), attrKey(attr.Channel, attr.Subtopic)).Err(); err != nil {
return errors.Wrap(ErrRedisTwinSave, err)
}
}
return nil
}
func (tc *twinCache) remove(ctx context.Context, twinID string) error {
twinKey := twinKey(twinID)
attrKeys, err := tc.client.SMembers(ctx, twinKey).Result()
if err != nil {
return errors.Wrap(ErrRedisTwinRemove, err)
}
if err := tc.client.Del(ctx, twinKey).Err(); err != nil {
return errors.Wrap(ErrRedisTwinRemove, err)
}
for _, attrKey := range attrKeys {
if err := tc.client.SRem(ctx, attrKey, twinID).Err(); err != nil {
return errors.Wrap(ErrRedisTwinRemove, err)
}
}
return nil
}
func twinKey(twinID string) string {
return fmt.Sprintf("%s:%s", prefix, twinID)
}
func attrKey(channel, subtopic string) string {
return fmt.Sprintf("%s:%s-%s", prefix, channel, subtopic)
}