/
redis_map_store.go
274 lines (239 loc) · 6.2 KB
/
redis_map_store.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 storage
import (
"sort"
"strings"
"github.com/TheThingsNetwork/ttn/utils/errors"
redis "gopkg.in/redis.v5"
)
// RedisMapStore stores structs as HMaps in Redis
type RedisMapStore struct {
prefix string
client *redis.Client
encoder StringStringMapEncoder
decoder StringStringMapDecoder
}
// NewRedisMapStore returns a new RedisMapStore that talks to the given Redis client and respects the given prefix
func NewRedisMapStore(client *redis.Client, prefix string) *RedisMapStore {
if !strings.HasSuffix(prefix, ":") {
prefix += ":"
}
return &RedisMapStore{
client: client,
prefix: prefix,
}
}
// SetBase sets the base struct for automatically encoding and decoding to and from Redis format
func (s *RedisMapStore) SetBase(base interface{}, tagName string) {
s.SetEncoder(buildDefaultStructEncoder(tagName))
s.SetDecoder(buildDefaultStructDecoder(base, tagName))
}
// SetEncoder sets the encoder to convert structs to Redis format
func (s *RedisMapStore) SetEncoder(encoder StringStringMapEncoder) {
s.encoder = encoder
}
// SetDecoder sets the decoder to convert structs from Redis format
func (s *RedisMapStore) SetDecoder(decoder StringStringMapDecoder) {
s.decoder = decoder
}
// GetAll returns all results for the given keys, prepending the prefix to the keys if necessary
func (s *RedisMapStore) GetAll(keys []string, options *ListOptions) ([]interface{}, error) {
if len(keys) == 0 {
return []interface{}{}, nil
}
for i, key := range keys {
if !strings.HasPrefix(key, s.prefix) {
keys[i] = s.prefix + key
}
}
sort.Strings(keys)
selectedKeys := selectKeys(keys, options)
pipe := s.client.Pipeline()
defer pipe.Close()
// Add all commands to pipeline
cmds := make(map[string]*redis.StringStringMapCmd)
for _, key := range selectedKeys {
cmds[key] = pipe.HGetAll(key)
}
// Execute pipeline
_, err := pipe.Exec()
if err != nil {
return nil, err
}
// Get all results from pipeline
results := make([]interface{}, 0, len(selectedKeys))
for _, key := range selectedKeys {
if result, err := cmds[key].Result(); err == nil {
if result, err := s.decoder(result); err == nil {
results = append(results, result)
}
}
}
return results, nil
}
// List all results matching the selector, prepending the prefix to the selector if necessary
func (s *RedisMapStore) List(selector string, options *ListOptions) ([]interface{}, error) {
if selector == "" {
selector = "*"
}
if !strings.HasPrefix(selector, s.prefix) {
selector = s.prefix + selector
}
keys, err := s.client.Keys(selector).Result()
if err != nil {
return nil, err
}
return s.GetAll(keys, options)
}
// Get one result, prepending the prefix to the key if necessary
func (s *RedisMapStore) Get(key string) (interface{}, error) {
if !strings.HasPrefix(key, s.prefix) {
key = s.prefix + key
}
result, err := s.client.HGetAll(key).Result()
if err == redis.Nil || len(result) == 0 {
return nil, errors.NewErrNotFound(key)
}
if err != nil {
return nil, err
}
i, err := s.decoder(result)
if err != nil {
return nil, err
}
return i, nil
}
// GetFields for a record, prepending the prefix to the key if necessary
func (s *RedisMapStore) GetFields(key string, fields ...string) (interface{}, error) {
if !strings.HasPrefix(key, s.prefix) {
key = s.prefix + key
}
result, err := s.client.HMGet(key, fields...).Result()
if err == redis.Nil {
return nil, errors.NewErrNotFound(key)
}
if err != nil {
return nil, err
}
res := make(map[string]string)
for i, field := range fields {
if str, ok := result[i].(string); ok {
res[field] = str
}
}
i, err := s.decoder(res)
if err != nil {
return nil, err
}
return i, nil
}
// ChangedFielder interface is used to see what fields to update
type ChangedFielder interface {
ChangedFields() []string
}
// Create a new record, prepending the prefix to the key if necessary, optionally setting only the given properties
func (s *RedisMapStore) Create(key string, value interface{}, properties ...string) error {
if !strings.HasPrefix(key, s.prefix) {
key = s.prefix + key
}
if len(properties) == 0 {
if i, ok := value.(ChangedFielder); ok {
properties = i.ChangedFields()
}
}
vmap, err := s.encoder(value, properties...)
if err != nil {
return err
}
if len(vmap) == 0 {
return nil
}
err = s.client.Watch(func(tx *redis.Tx) error {
exists, err := tx.Exists(key).Result()
if err != nil {
return err
}
if exists {
return errors.NewErrAlreadyExists(key)
}
_, err = tx.Pipelined(func(pipe *redis.Pipeline) error {
pipe.HMSet(key, vmap)
return nil
})
if err != nil {
return err
}
return nil
}, key)
if err != nil {
return err
}
return nil
}
// Update an existing record, prepending the prefix to the key if necessary, optionally setting only the given properties
func (s *RedisMapStore) Update(key string, value interface{}, properties ...string) error {
if !strings.HasPrefix(key, s.prefix) {
key = s.prefix + key
}
if len(properties) == 0 {
if i, ok := value.(ChangedFielder); ok {
properties = i.ChangedFields()
}
}
vmap, err := s.encoder(value, properties...)
if err != nil {
return err
}
if len(vmap) == 0 {
return nil
}
err = s.client.Watch(func(tx *redis.Tx) error {
exists, err := tx.Exists(key).Result()
if err != nil {
return err
}
if !exists {
return errors.NewErrNotFound(key)
}
_, err = tx.Pipelined(func(pipe *redis.Pipeline) error {
pipe.HMSet(key, vmap)
return nil
})
if err != nil {
return err
}
return nil
}, key)
if err != nil {
return err
}
return nil
}
// Delete an existing record, prepending the prefix to the key if necessary
func (s *RedisMapStore) Delete(key string) error {
if !strings.HasPrefix(key, s.prefix) {
key = s.prefix + key
}
err := s.client.Watch(func(tx *redis.Tx) error {
exists, err := tx.Exists(key).Result()
if err != nil {
return err
}
if !exists {
return errors.NewErrNotFound(key)
}
_, err = tx.Pipelined(func(pipe *redis.Pipeline) error {
pipe.Del(key)
return nil
})
if err != nil {
return err
}
return nil
}, key)
if err != nil {
return err
}
return nil
}