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 means seeking through all keys in the DB starting from // the Start if specified. 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 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) 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 } // 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) } 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 }