neo-go/pkg/core/storage/store.go
Vsevolod Brekelov 4f680703a4 storage: multiple DB support and Redis support
add config which closes #336
add redis db support
2019-09-10 17:22:21 +03:00

90 lines
2.3 KiB
Go

package storage
import (
"context"
"encoding/binary"
"errors"
)
// KeyPrefix constants.
const (
DataBlock KeyPrefix = 0x01
DataTransaction KeyPrefix = 0x02
STAccount KeyPrefix = 0x40
STCoin KeyPrefix = 0x44
STSpentCoin KeyPrefix = 0x45
STValidator KeyPrefix = 0x48
STAsset KeyPrefix = 0x4c
STContract KeyPrefix = 0x50
STStorage KeyPrefix = 0x70
IXHeaderHashList KeyPrefix = 0x80
IXValidatorsCount KeyPrefix = 0x90
SYSCurrentBlock KeyPrefix = 0xc0
SYSCurrentHeader KeyPrefix = 0xc1
SYSVersion KeyPrefix = 0xf0
)
// ErrKeyNotFound is an error returned by Store implementations
// when a certain key is not found.
var ErrKeyNotFound = errors.New("key not found")
type (
// Store is anything that can persist and retrieve the blockchain.
// information.
Store interface {
Batch() Batch
Get([]byte) ([]byte, error)
Put(k, v []byte) error
PutBatch(Batch) error
Seek(k []byte, f func(k, v []byte))
}
// Batch represents an abstraction on top of batch operations.
// Each Store implementation is responsible of casting a Batch
// to its appropriate type.
Batch interface {
Put(k, v []byte)
Len() int
}
// KeyPrefix is a constant byte added as a prefix for each key
// stored.
KeyPrefix uint8
)
// Bytes returns the bytes representation of KeyPrefix.
func (k KeyPrefix) Bytes() []byte {
return []byte{byte(k)}
}
// AppendPrefix append byteslice b to the given KeyPrefix.
// AppendKeyPrefix(SYSVersion, []byte{0x00, 0x01})
func AppendPrefix(k KeyPrefix, b []byte) []byte {
dest := make([]byte, len(b)+1)
dest[0] = byte(k)
copy(dest[1:], b)
return dest
}
// AppendPrefixInt append int n to the given KeyPrefix.
// AppendPrefixInt(SYSCurrentHeader, 10001)
func AppendPrefixInt(k KeyPrefix, n int) []byte {
b := make([]byte, 4)
binary.LittleEndian.PutUint32(b, uint32(n))
return AppendPrefix(k, b)
}
// NewStore creates storage with preselected in configuration database type.
func NewStore(context context.Context, cfg DBConfiguration) (Store, error) {
var store Store
var err error
switch cfg.Type {
case "leveldb":
store, err = NewLevelDBStore(context, cfg.LevelDBOptions)
case "inmemory":
store = NewMemoryStore()
case "redis":
store, err = NewRedisStore(cfg.RedisDBOptions)
}
return store, err
}