/
shard.go
60 lines (51 loc) · 1.18 KB
/
shard.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
package storages
import (
"io"
)
// Sharding pool
type ShardPool interface {
// Get storage based on key
Get(key []byte) (Storage, error)
// Iterate over shards
Iterate(handler func(storage Storage) error) error
io.Closer
}
// Sharded storage with defined pool (strategy)
func Sharded(pool ShardPool) Storage {
return &shardedStorage{pool: pool}
}
type shardedStorage struct {
pool ShardPool
}
func (shard *shardedStorage) Put(key []byte, data []byte) error {
storage, err := shard.pool.Get(key)
if err != nil {
return err
}
defer storage.Close()
return storage.Put(key, data)
}
func (shard *shardedStorage) Close() error {
return shard.pool.Close()
}
func (shard *shardedStorage) Get(key []byte) ([]byte, error) {
storage, err := shard.pool.Get(key)
if err != nil {
return nil, err
}
defer storage.Close()
return storage.Get(key)
}
func (shard *shardedStorage) Del(key []byte) error {
storage, err := shard.pool.Get(key)
if err != nil {
return err
}
defer storage.Close()
return storage.Del(key)
}
func (shard *shardedStorage) Keys(handler func(key []byte) error) error {
return shard.pool.Iterate(func(storage Storage) error {
return storage.Keys(handler)
})
}