Mainflux.mainflux/things/cache/things.go

81 lines
1.9 KiB
Go

// Copyright (c) Mainflux
// SPDX-License-Identifier: Apache-2.0
package cache
import (
"context"
"fmt"
"time"
"github.com/go-redis/redis/v8"
"github.com/mainflux/mainflux/pkg/errors"
"github.com/mainflux/mainflux/things"
)
const (
keyPrefix = "thing_key"
idPrefix = "thing_id"
)
var _ things.Cache = (*thingCache)(nil)
type thingCache struct {
client *redis.Client
keyDuration time.Duration
}
// NewCache returns redis thing cache implementation.
func NewCache(client *redis.Client, duration time.Duration) things.Cache {
return &thingCache{
client: client,
keyDuration: duration,
}
}
func (tc *thingCache) Save(ctx context.Context, thingKey string, thingID string) error {
tkey := fmt.Sprintf("%s:%s", keyPrefix, thingKey)
if err := tc.client.Set(ctx, tkey, thingID, tc.keyDuration).Err(); err != nil {
return errors.Wrap(errors.ErrCreateEntity, err)
}
tid := fmt.Sprintf("%s:%s", idPrefix, thingID)
if err := tc.client.Set(ctx, tid, thingKey, tc.keyDuration).Err(); err != nil {
return errors.Wrap(errors.ErrCreateEntity, err)
}
return nil
}
func (tc *thingCache) ID(ctx context.Context, thingKey string) (string, error) {
tkey := fmt.Sprintf("%s:%s", keyPrefix, thingKey)
thingID, err := tc.client.Get(ctx, tkey).Result()
if err != nil {
return "", errors.Wrap(errors.ErrNotFound, err)
}
if thingID == "" {
return "", errors.ErrNotFound
}
return thingID, nil
}
func (tc *thingCache) Remove(ctx context.Context, thingID string) error {
tid := fmt.Sprintf("%s:%s", idPrefix, thingID)
key, err := tc.client.Get(ctx, tid).Result()
// Redis returns Nil Reply when key does not exist.
if err == redis.Nil {
return nil
}
if err != nil {
return errors.Wrap(errors.ErrRemoveEntity, err)
}
tkey := fmt.Sprintf("%s:%s", keyPrefix, key)
if err := tc.client.Del(ctx, tkey, tid).Err(); err != nil {
return errors.Wrap(errors.ErrRemoveEntity, err)
}
return nil
}