neoneo-go/pkg/core/storage/store.go
2021-10-27 17:32:25 +03:00

115 lines
3.6 KiB
Go

package storage
import (
"encoding/binary"
"errors"
"fmt"
)
// KeyPrefix constants.
const (
DataBlock KeyPrefix = 0x01
DataTransaction KeyPrefix = 0x02
DataMPT KeyPrefix = 0x03
STAccount KeyPrefix = 0x40
STNotification KeyPrefix = 0x4d
STContractID KeyPrefix = 0x51
STStorage KeyPrefix = 0x70
// STTempStorage is used to store contract storage items during state sync process
// in order not to mess up the previous state which has its own items stored by
// STStorage prefix. Once state exchange process is completed, all items with
// STStorage prefix will be replaced with STTempStorage-prefixed ones.
STTempStorage KeyPrefix = 0x71
STNEP17Transfers KeyPrefix = 0x72
STNEP17TransferInfo KeyPrefix = 0x73
IXHeaderHashList KeyPrefix = 0x80
SYSCurrentBlock KeyPrefix = 0xc0
SYSCurrentHeader KeyPrefix = 0xc1
SYSStateSyncCurrentBlockHeight KeyPrefix = 0xc2
SYSStateSyncPoint KeyPrefix = 0xc3
SYSStateJumpStage KeyPrefix = 0xc4
SYSVersion KeyPrefix = 0xf0
)
const (
// MaxStorageKeyLen is the maximum length of a key for storage items.
MaxStorageKeyLen = 64
// MaxStorageValueLen is the maximum length of a value for storage items.
// It is set to be the maximum value for uint16.
MaxStorageValueLen = 65535
)
// 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
Delete(k []byte) error
Get([]byte) ([]byte, error)
Put(k, v []byte) error
PutBatch(Batch) error
// PutChangeSet allows to push prepared changeset to the Store.
PutChangeSet(puts map[string][]byte, dels map[string]bool) error
// Seek can guarantee that provided key (k) and value (v) are the only valid until the next call to f.
// Key and value slices should not be modified. Seek can guarantee that key-value items are sorted by
// key in ascending way.
Seek(k []byte, f func(k, v []byte))
Close() error
}
// Batch represents an abstraction on top of batch operations.
// Each Store implementation is responsible of casting a Batch
// to its appropriate type. Batches can only be used in a single
// thread.
Batch interface {
Delete(k []byte)
Put(k, v []byte)
}
// 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 appends 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(cfg DBConfiguration) (Store, error) {
var store Store
var err error
switch cfg.Type {
case "leveldb":
store, err = NewLevelDBStore(cfg.LevelDBOptions)
case "inmemory":
store = NewMemoryStore()
case "boltdb":
store, err = NewBoltDBStore(cfg.BoltDBOptions)
default:
return nil, fmt.Errorf("unknown storage: %s", cfg.Type)
}
return store, err
}