neo-go/pkg/core/storage/store.go
Roman Khimov be24bf6412 storage: drop Put and Delete from Store interface
It's only changed with PutChangeSet, single KV operations are handled by
MemCachedStore.
2022-02-16 18:24:20 +03:00

202 lines
6.2 KiB
Go

package storage
import (
"encoding/binary"
"errors"
"fmt"
"github.com/syndtr/goleveldb/leveldb/util"
)
// KeyPrefix constants.
const (
DataExecutable KeyPrefix = 0x01
// DataMPT is used for MPT node entries identified by Uint256.
DataMPT KeyPrefix = 0x03
// DataMPTAux is used to store additional MPT data like height-root
// mappings and local/validated heights.
DataMPTAux KeyPrefix = 0x04
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
STNEP11Transfers KeyPrefix = 0x72
STNEP17Transfers KeyPrefix = 0x73
STTokenTransferInfo KeyPrefix = 0x74
IXHeaderHashList KeyPrefix = 0x80
SYSCurrentBlock KeyPrefix = 0xc0
SYSCurrentHeader KeyPrefix = 0xc1
SYSStateSyncCurrentBlockHeight KeyPrefix = 0xc2
SYSStateSyncPoint KeyPrefix = 0xc3
SYSStateJumpStage KeyPrefix = 0xc4
SYSVersion KeyPrefix = 0xf0
)
// Executable subtypes.
const (
ExecBlock byte = 1
ExecTransaction byte = 2
)
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
)
// Operation represents a single KV operation (add/del/change) performed
// in the DB.
type Operation struct {
// State can be Added, Changed or Deleted.
State string `json:"state"`
Key []byte `json:"key"`
Value []byte `json:"value,omitempty"`
}
// SeekRange represents options for Store.Seek operation.
type SeekRange struct {
// Prefix denotes the Seek's lookup key.
// Empty Prefix is not supported.
Prefix []byte
// Start denotes value appended to the Prefix to start Seek from.
// Seeking starting from some key includes this key to the result;
// if no matching key was found then next suitable key is picked up.
// Start may be empty. Empty Start means seeking through all keys in
// the DB with matching Prefix.
// Empty Prefix and empty Start can be combined, which means seeking
// through all keys in the DB.
Start []byte
// Backwards denotes whether Seek direction should be reversed, i.e.
// whether seeking should be performed in a descending way.
// Backwards can be safely combined with Prefix and Start.
Backwards bool
}
// 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 the underlying KV backend for the blockchain data, it's
// not intended to be used directly, you wrap it with some memory cache
// layer most of the time.
Store interface {
Get([]byte) ([]byte, error)
// PutChangeSet allows to push prepared changeset to the Store.
PutChangeSet(puts map[string][]byte, stor map[string][]byte) error
// Seek can guarantee that provided key (k) and value (v) are the only valid until the next call to f.
// Seek continues iteration until false is returned from f.
// Key and value slices should not be modified.
// Seek can guarantee that key-value items are sorted by key in ascending way.
Seek(rng SeekRange, f func(k, v []byte) bool)
// SeekGC is similar to Seek, but the function should return true if current
// KV pair should be kept and false if it's to be deleted; there is no way to
// do an early exit here. SeekGC only works with the current Store, it won't
// go down to layers below and it takes a full write lock, so use it carefully.
SeekGC(rng SeekRange, keep func(k, v []byte) bool) error
Close() error
}
// 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)
}
func seekRangeToPrefixes(sr SeekRange) *util.Range {
var (
rang *util.Range
start = make([]byte, len(sr.Prefix)+len(sr.Start))
)
copy(start, sr.Prefix)
copy(start[len(sr.Prefix):], sr.Start)
if !sr.Backwards {
rang = util.BytesPrefix(sr.Prefix)
rang.Start = start
} else {
rang = util.BytesPrefix(start)
rang.Start = sr.Prefix
}
return rang
}
// 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
}
// BatchToOperations converts a batch of changes into array of Operations.
func BatchToOperations(batch *MemBatch) []Operation {
size := len(batch.Put) + len(batch.Deleted)
ops := make([]Operation, 0, size)
for i := range batch.Put {
key := batch.Put[i].Key
if len(key) == 0 || key[0] != byte(STStorage) && key[0] != byte(STTempStorage) {
continue
}
op := "Added"
if batch.Put[i].Exists {
op = "Changed"
}
ops = append(ops, Operation{
State: op,
Key: key[1:],
Value: batch.Put[i].Value,
})
}
for i := range batch.Deleted {
key := batch.Deleted[i].Key
if len(key) == 0 || !batch.Deleted[i].Exists ||
key[0] != byte(STStorage) && key[0] != byte(STTempStorage) {
continue
}
ops = append(ops, Operation{
State: "Deleted",
Key: key[1:],
})
}
return ops
}