Golang rlp.DecodeBytes函數代碼示例

// GetTransaction retrieves a specific transaction from the database, along with
// its added positional metadata.
func GetTransaction(db ethdb.Database, hash common.Hash) (*types.Transaction, common.Hash, uint64, uint64) {
	// Retrieve the transaction itself from the database
	data, _ := db.Get(hash.Bytes())
	if len(data) == 0 {
		return nil, common.Hash{}, 0, 0
	}
	var tx types.Transaction
	if err := rlp.DecodeBytes(data, &tx); err != nil {
		return nil, common.Hash{}, 0, 0
	}
	// Retrieve the blockchain positional metadata
	data, _ = db.Get(append(hash.Bytes(), txMetaSuffix...))
	if len(data) == 0 {
		return nil, common.Hash{}, 0, 0
	}
	var meta struct {
		BlockHash  common.Hash
		BlockIndex uint64
		Index      uint64
	}
	if err := rlp.DecodeBytes(data, &meta); err != nil {
		return nil, common.Hash{}, 0, 0
	}
	return &tx, meta.BlockHash, meta.BlockIndex, meta.Index
}

// DecodeRLP is a specialized decoder for hashOrNumber to decode the contents
// into either a block hash or a block number.
func (hn *hashOrNumber) DecodeRLP(s *rlp.Stream) error {
	_, size, _ := s.Kind()
	origin, err := s.Raw()
	if err == nil {
		switch {
		case size == 32:
			err = rlp.DecodeBytes(origin, &hn.Hash)
		case size <= 8:
			err = rlp.DecodeBytes(origin, &hn.Number)
		default:
			err = fmt.Errorf("invalid input size %d for origin", size)
		}
	}
	return err
}

func (self *StateDB) RawDump() Dump {
	dump := Dump{
		Root:     common.Bytes2Hex(self.trie.Root()),
		Accounts: make(map[string]DumpAccount),
	}

	it := self.trie.Iterator()
	for it.Next() {
		addr := self.trie.GetKey(it.Key)
		var data Account
		if err := rlp.DecodeBytes(it.Value, &data); err != nil {
			panic(err)
		}

		obj := newObject(nil, common.BytesToAddress(addr), data, nil)
		account := DumpAccount{
			Balance:  data.Balance.String(),
			Nonce:    data.Nonce,
			Root:     common.Bytes2Hex(data.Root[:]),
			CodeHash: common.Bytes2Hex(data.CodeHash),
			Code:     common.Bytes2Hex(obj.Code(self.db)),
			Storage:  make(map[string]string),
		}
		storageIt := obj.getTrie(self.db).Iterator()
		for storageIt.Next() {
			account.Storage[common.Bytes2Hex(self.trie.GetKey(storageIt.Key))] = common.Bytes2Hex(storageIt.Value)
		}
		dump.Accounts[common.Bytes2Hex(addr)] = account
	}
	return dump
}

func (self *XEth) PushTx(encodedTx string) (string, error) {
	tx := new(types.Transaction)
	err := rlp.DecodeBytes(common.FromHex(encodedTx), tx)
	if err != nil {
		glog.V(logger.Error).Infoln(err)
		return "", err
	}

	err = self.backend.TxPool().Add(tx)
	if err != nil {
		return "", err
	}

	if tx.To() == nil {
		from, err := tx.From()
		if err != nil {
			return "", err
		}

		addr := crypto.CreateAddress(from, tx.Nonce())
		glog.V(logger.Info).Infof("Tx(%x) created: %x\n", tx.Hash(), addr)
	} else {
		glog.V(logger.Info).Infof("Tx(%x) to: %x\n", tx.Hash(), tx.To())
	}

	return tx.Hash().Hex(), nil
}

func decodePacket(buf []byte) (packet, NodeID, []byte, error) {
	if len(buf) < headSize+1 {
		return nil, NodeID{}, nil, errPacketTooSmall
	}
	hash, sig, sigdata := buf[:macSize], buf[macSize:headSize], buf[headSize:]
	shouldhash := crypto.Sha3(buf[macSize:])
	if !bytes.Equal(hash, shouldhash) {
		return nil, NodeID{}, nil, errBadHash
	}
	fromID, err := recoverNodeID(crypto.Sha3(buf[headSize:]), sig)
	if err != nil {
		return nil, NodeID{}, hash, err
	}
	var req packet
	switch ptype := sigdata[0]; ptype {
	case pingPacket:
		req = new(ping)
	case pongPacket:
		req = new(pong)
	case findnodePacket:
		req = new(findnode)
	case neighborsPacket:
		req = new(neighbors)
	default:
		return nil, fromID, hash, fmt.Errorf("unknown type: %d", ptype)
	}
	err = rlp.DecodeBytes(sigdata[1:], req)
	return req, fromID, hash, err
}

// NewValueFromBytes decodes RLP data.
// The contained value will be nil if data contains invalid RLP.
func NewValueFromBytes(data []byte) *Value {
	v := new(Value)
	if len(data) != 0 {
		if err := rlp.DecodeBytes(data, v); err != nil {
			v.Val = nil
		}
	}
	return v
}

// getAddr gets the storage value at the given address from the trie
func (c *StateObject) getAddr(ctx context.Context, addr common.Hash) (common.Hash, error) {
	var ret []byte
	val, err := c.trie.Get(ctx, addr[:])
	if err != nil {
		return common.Hash{}, err
	}
	rlp.DecodeBytes(val, &ret)
	return common.BytesToHash(ret), nil
}

func checkDecodeInterface(b []byte, isValid bool) error {
	err := rlp.DecodeBytes(b, new(interface{}))
	switch {
	case isValid && err != nil:
		return fmt.Errorf("decoding failed: %v", err)
	case !isValid && err == nil:
		return fmt.Errorf("decoding of invalid value succeeded")
	}
	return nil
}

// GetReceipt returns a receipt by hash
func GetReceipt(db ethdb.Database, txHash common.Hash) *types.Receipt {
	data, _ := db.Get(append(receiptsPrefix, txHash[:]...))
	if len(data) == 0 {
		return nil
	}
	var receipt types.ReceiptForStorage
	err := rlp.DecodeBytes(data, &receipt)
	if err != nil {
		glog.V(logger.Core).Infoln("GetReceipt err:", err)
	}
	return (*types.Receipt)(&receipt)
}

// GetBlockReceipts returns the receipts generated by the transactions
// included in block's given hash.
func GetBlockReceipts(db common.Database, hash common.Hash) types.Receipts {
	data, _ := db.Get(append(blockReceiptsPre, hash[:]...))
	if len(data) == 0 {
		return nil
	}

	var receipts types.Receipts
	err := rlp.DecodeBytes(data, &receipts)
	if err != nil {
		glog.V(logger.Core).Infoln("GetReceiptse err", err)
	}
	return receipts
}

// node retrieves a node with a given id from the database.
func (db *nodeDB) node(id NodeID) *Node {
	blob, err := db.lvl.Get(makeKey(id, nodeDBDiscoverRoot), nil)
	if err != nil {
		glog.V(logger.Detail).Infof("failed to retrieve node %v: %v", id, err)
		return nil
	}
	node := new(Node)
	if err := rlp.DecodeBytes(blob, node); err != nil {
		glog.V(logger.Warn).Infof("failed to decode node RLP: %v", err)
		return nil
	}
	node.sha = crypto.Sha3Hash(node.ID[:])
	return node
}

// GetBlockReceipts retrieves the receipts generated by the transactions included
// in a block given by its hash.
func GetBlockReceipts(db ethdb.Database, hash common.Hash) types.Receipts {
	data, _ := db.Get(append(blockReceiptsPrefix, hash[:]...))
	if len(data) == 0 {
		return nil
	}
	storageReceipts := []*types.ReceiptForStorage{}
	if err := rlp.DecodeBytes(data, &storageReceipts); err != nil {
		glog.V(logger.Error).Infof("invalid receipt array RLP for hash %x: %v", hash, err)
		return nil
	}
	receipts := make(types.Receipts, len(storageReceipts))
	for i, receipt := range storageReceipts {
		receipts[i] = (*types.Receipt)(receipt)
	}
	return receipts
}

// DecodeRLP decodes an Envelope from an RLP data stream.
func (self *Envelope) DecodeRLP(s *rlp.Stream) error {
	raw, err := s.Raw()
	if err != nil {
		return err
	}
	// The decoding of Envelope uses the struct fields but also needs
	// to compute the hash of the whole RLP-encoded envelope. This
	// type has the same structure as Envelope but is not an
	// rlp.Decoder so we can reuse the Envelope struct definition.
	type rlpenv Envelope
	if err := rlp.DecodeBytes(raw, (*rlpenv)(self)); err != nil {
		return err
	}
	self.hash = crypto.Sha3Hash(raw)
	return nil
}

// reads the next node record from the iterator, skipping over other
// database entries.
func nextNode(it iterator.Iterator) *Node {
	for end := false; !end; end = !it.Next() {
		id, field := splitKey(it.Key())
		if field != nodeDBDiscoverRoot {
			continue
		}
		var n Node
		if err := rlp.DecodeBytes(it.Value(), &n); err != nil {
			if glog.V(logger.Warn) {
				glog.Errorf("invalid node %x: %v", id, err)
			}
			continue
		}
		return &n
	}
	return nil
}

// Tests that the custom union field encoder and decoder works correctly.
func TestGetBlockHeadersDataEncodeDecode(t *testing.T) {
	// Create a "random" hash for testing
	var hash common.Hash
	for i, _ := range hash {
		hash[i] = byte(i)
	}
	// Assemble some table driven tests
	tests := []struct {
		packet *getBlockHeadersData
		fail   bool
	}{
		// Providing the origin as either a hash or a number should both work
		{fail: false, packet: &getBlockHeadersData{Origin: hashOrNumber{Number: 314}}},
		{fail: false, packet: &getBlockHeadersData{Origin: hashOrNumber{Hash: hash}}},

		// Providing arbitrary query field should also work
		{fail: false, packet: &getBlockHeadersData{Origin: hashOrNumber{Number: 314}, Amount: 314, Skip: 1, Reverse: true}},
		{fail: false, packet: &getBlockHeadersData{Origin: hashOrNumber{Hash: hash}, Amount: 314, Skip: 1, Reverse: true}},

		// Providing both the origin hash and origin number must fail
		{fail: true, packet: &getBlockHeadersData{Origin: hashOrNumber{Hash: hash, Number: 314}}},
	}
	// Iterate over each of the tests and try to encode and then decode
	for i, tt := range tests {
		bytes, err := rlp.EncodeToBytes(tt.packet)
		if err != nil && !tt.fail {
			t.Fatalf("test %d: failed to encode packet: %v", i, err)
		} else if err == nil && tt.fail {
			t.Fatalf("test %d: encode should have failed", i)
		}
		if !tt.fail {
			packet := new(getBlockHeadersData)
			if err := rlp.DecodeBytes(bytes, packet); err != nil {
				t.Fatalf("test %d: failed to decode packet: %v", i, err)
			}
			if packet.Origin.Hash != tt.packet.Origin.Hash || packet.Origin.Number != tt.packet.Origin.Number || packet.Amount != tt.packet.Amount ||
				packet.Skip != tt.packet.Skip || packet.Reverse != tt.packet.Reverse {
				t.Fatalf("test %d: encode decode mismatch: have %+v, want %+v", i, packet, tt.packet)
			}
		}
	}
}