Golang ethdb.Database類代碼示例

func NewStateObjectFromBytes(address common.Address, data []byte, db ethdb.Database) *StateObject {
	var extobject struct {
		Nonce    uint64
		Balance  *big.Int
		Root     common.Hash
		CodeHash []byte
	}
	err := rlp.Decode(bytes.NewReader(data), &extobject)
	if err != nil {
		glog.Errorf("can't decode state object %x: %v", address, err)
		return nil
	}
	trie, err := trie.NewSecure(extobject.Root, db)
	if err != nil {
		// TODO: bubble this up or panic
		glog.Errorf("can't create account trie with root %x: %v", extobject.Root[:], err)
		return nil
	}

	object := &StateObject{address: address, db: db}
	object.nonce = extobject.Nonce
	object.balance = extobject.Balance
	object.codeHash = extobject.CodeHash
	object.trie = trie
	object.storage = make(map[string]common.Hash)
	object.code, _ = db.Get(extobject.CodeHash)
	return object
}

func NewStateObjectFromBytes(address common.Address, data []byte, db ethdb.Database) *StateObject {
	// TODO clean me up
	var extobject struct {
		Nonce    uint64
		Balance  *big.Int
		Root     common.Hash
		CodeHash []byte
	}
	err := rlp.Decode(bytes.NewReader(data), &extobject)
	if err != nil {
		fmt.Println(err)
		return nil
	}

	object := &StateObject{address: address, db: db}
	object.nonce = extobject.Nonce
	object.balance = extobject.Balance
	object.codeHash = extobject.CodeHash
	object.trie = trie.NewSecure(extobject.Root[:], db)
	object.storage = make(map[string]common.Hash)
	object.gasPool = new(big.Int)
	object.code, _ = db.Get(extobject.CodeHash)

	return object
}

func benchInsertChain(b *testing.B, disk bool, gen func(int, *BlockGen)) {
	// Create the database in memory or in a temporary directory.
	var db ethdb.Database
	if !disk {
		db, _ = ethdb.NewMemDatabase()
	} else {
		dir, err := ioutil.TempDir("", "eth-core-bench")
		if err != nil {
			b.Fatalf("cannot create temporary directory: %v", err)
		}
		defer os.RemoveAll(dir)
		db, err = ethdb.NewLDBDatabase(dir, 0)
		if err != nil {
			b.Fatalf("cannot create temporary database: %v", err)
		}
		defer db.Close()
	}

	// Generate a chain of b.N blocks using the supplied block
	// generator function.
	genesis := WriteGenesisBlockForTesting(db, GenesisAccount{benchRootAddr, benchRootFunds})
	chain, _ := GenerateChain(genesis, db, b.N, gen)

	// Time the insertion of the new chain.
	// State and blocks are stored in the same DB.
	evmux := new(event.TypeMux)
	chainman, _ := NewBlockChain(db, FakePow{}, evmux)
	chainman.SetProcessor(NewBlockProcessor(db, FakePow{}, chainman, evmux))
	defer chainman.Stop()
	b.ReportAllocs()
	b.ResetTimer()
	if i, err := chainman.InsertChain(chain); err != nil {
		b.Fatalf("insert error (block %d): %v\n", i, err)
	}
}

// WriteHeadFastBlockHash stores the fast head block's hash.
func WriteHeadFastBlockHash(db ethdb.Database, hash common.Hash) error {
	if err := db.Put(headFastKey, hash.Bytes()); err != nil {
		glog.Fatalf("failed to store last fast block's hash into database: %v", err)
		return err
	}
	return nil
}

// PutTransactions stores the transactions in the given database
func PutTransactions(db ethdb.Database, block *types.Block, txs types.Transactions) error {
	batch := db.NewBatch()

	for i, tx := range block.Transactions() {
		rlpEnc, err := rlp.EncodeToBytes(tx)
		if err != nil {
			return fmt.Errorf("failed encoding tx: %v", err)
		}

		batch.Put(tx.Hash().Bytes(), rlpEnc)

		var txExtra struct {
			BlockHash  common.Hash
			BlockIndex uint64
			Index      uint64
		}
		txExtra.BlockHash = block.Hash()
		txExtra.BlockIndex = block.NumberU64()
		txExtra.Index = uint64(i)
		rlpMeta, err := rlp.EncodeToBytes(txExtra)
		if err != nil {
			return fmt.Errorf("failed encoding tx meta data: %v", err)
		}

		batch.Put(append(tx.Hash().Bytes(), 0x0001), rlpMeta)
	}

	if err := batch.Write(); err != nil {
		return fmt.Errorf("failed writing tx to db: %v", err)
	}
	return nil
}

// PutReceipts stores the receipts in the current database
func PutReceipts(db ethdb.Database, receipts types.Receipts) error {
	batch := new(leveldb.Batch)
	_, batchWrite := db.(*ethdb.LDBDatabase)

	for _, receipt := range receipts {
		storageReceipt := (*types.ReceiptForStorage)(receipt)
		bytes, err := rlp.EncodeToBytes(storageReceipt)
		if err != nil {
			return err
		}

		if batchWrite {
			batch.Put(append(receiptsPre, receipt.TxHash[:]...), bytes)
		} else {
			err = db.Put(append(receiptsPre, receipt.TxHash[:]...), bytes)
			if err != nil {
				return err
			}
		}
	}
	if db, ok := db.(*ethdb.LDBDatabase); ok {
		if err := db.LDB().Write(batch, nil); err != nil {
			return err
		}
	}

	return nil
}

// GetCanonicalHash retrieves a hash assigned to a canonical block number.
func GetCanonicalHash(db ethdb.Database, number uint64) common.Hash {
	data, _ := db.Get(append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...))
	if len(data) == 0 {
		return common.Hash{}
	}
	return common.BytesToHash(data)
}

// 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
}

// GetHeadFastBlockHash retrieves the hash of the current canonical head block during
// fast synchronization. The difference between this and GetHeadBlockHash is that
// whereas the last block hash is only updated upon a full block import, the last
// fast hash is updated when importing pre-processed blocks.
func GetHeadFastBlockHash(db ethdb.Database) common.Hash {
	data, _ := db.Get(headFastKey)
	if len(data) == 0 {
		return common.Hash{}
	}
	return common.BytesToHash(data)
}

// WriteCanonicalHash stores the canonical hash for the given block number.
func WriteCanonicalHash(db ethdb.Database, hash common.Hash, number uint64) error {
	key := append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...)
	if err := db.Put(key, hash.Bytes()); err != nil {
		glog.Fatalf("failed to store number to hash mapping into database: %v", err)
		return err
	}
	return nil
}

func saveBlockchainVersion(db ethdb.Database, bcVersion int) {
	d, _ := db.Get([]byte("BlockchainVersion"))
	blockchainVersion := common.NewValue(d).Uint()

	if blockchainVersion == 0 {
		db.Put([]byte("BlockchainVersion"), common.NewValue(bcVersion).Bytes())
	}
}

// storeProof stores the new trie nodes obtained from a merkle proof in the database
func storeProof(db ethdb.Database, proof []rlp.RawValue) {
	for _, buf := range proof {
		hash := crypto.Keccak256(buf)
		val, _ := db.Get(hash)
		if val == nil {
			db.Put(hash, buf)
		}
	}
}

func GetTransaction(db ethdb.Database, txhash common.Hash) *types.Transaction {
	data, _ := db.Get(txhash[:])
	if len(data) != 0 {
		var tx types.Transaction
		if err := rlp.DecodeBytes(data, &tx); err != nil {
			return nil
		}
		return &tx
	}
	return nil
}

// GetTd retrieves a block's total difficulty corresponding to the hash, nil if
// none found.
func GetTd(db ethdb.Database, hash common.Hash) *big.Int {
	data, _ := db.Get(append(append(blockPrefix, hash.Bytes()...), tdSuffix...))
	if len(data) == 0 {
		return nil
	}
	td := new(big.Int)
	if err := rlp.Decode(bytes.NewReader(data), td); err != nil {
		glog.V(logger.Error).Infof("invalid block total difficulty RLP for hash %x: %v", hash, err)
		return nil
	}
	return td
}

// 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)
}