Golang common.Database類代碼示例

func NewStateObjectFromBytes(address common.Address, data []byte, db common.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.prepaid = new(big.Int)
	object.code, _ = db.Get(extobject.CodeHash)

	return object
}

// PutTransactions stores the transactions in the given database
func PutTransactions(db common.Database, block *types.Block, txs types.Transactions) {
	for i, tx := range block.Transactions() {
		rlpEnc, err := rlp.EncodeToBytes(tx)
		if err != nil {
			glog.V(logger.Debug).Infoln("Failed encoding tx", err)
			return
		}
		db.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 {
			glog.V(logger.Debug).Infoln("Failed encoding tx meta data", err)
			return
		}
		db.Put(append(tx.Hash().Bytes(), 0x0001), rlpMeta)
	}
}

// PutReceipts stores the receipts in the current database
func PutReceipts(db common.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
}

func benchInsertChain(b *testing.B, disk bool, gen func(int, *BlockGen)) {
	// Create the database in memory or in a temporary directory.
	var db common.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, 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, _ := NewChainManager(db, db, db, FakePow{}, evmux)
	chainman.SetProcessor(NewBlockProcessor(db, 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)
	}
}

func saveProtocolVersion(db common.Database, protov int) {
	d, _ := db.Get([]byte("ProtocolVersion"))
	protocolVersion := common.NewValue(d).Uint()

	if protocolVersion == 0 {
		db.Put([]byte("ProtocolVersion"), common.NewValue(protov).Bytes())
	}
}

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

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

// WriteCanonNumber writes the canonical hash for the given block
func WriteCanonNumber(db common.Database, block *types.Block) error {
	key := append(blockNumPre, block.Number().Bytes()...)
	err := db.Put(key, block.Hash().Bytes())
	if err != nil {
		return err
	}
	return nil
}

// GetBlockByHash returns the canonical block by number or nil if not found
func GetBlockByNumber(db common.Database, number uint64) *types.Block {
	key, _ := db.Get(append(blockNumPre, big.NewInt(int64(number)).Bytes()...))
	if len(key) == 0 {
		return nil
	}

	return GetBlockByHash(db, common.BytesToHash(key))
}

// WriteHead force writes the current head
func WriteHead(db common.Database, block *types.Block) error {
	err := WriteCanonNumber(db, block)
	if err != nil {
		return err
	}
	err = db.Put([]byte("LastBlock"), block.Hash().Bytes())
	if err != nil {
		return err
	}
	return nil
}

func getBlockReceipts(db common.Database, bhash common.Hash) (receipts types.Receipts, err error) {
	var rdata []byte
	rdata, err = db.Get(append(receiptsPre, bhash[:]...))

	if err == nil {
		err = rlp.DecodeBytes(rdata, &receipts)
	} else {
		glog.V(logger.Detail).Infof("getBlockReceipts error %v\n", err)
	}
	return
}

// WriteHead force writes the current head
func WriteHead(db common.Database, block *types.Block) error {
	key := append(blockNumPre, block.Number().Bytes()...)
	err := db.Put(key, block.Hash().Bytes())
	if err != nil {
		return err
	}
	err = db.Put([]byte("LastBlock"), block.Hash().Bytes())
	if err != nil {
		return err
	}
	return nil
}

// GetBlockByHash returns the block corresponding to the hash or nil if not found
func GetBlockByHash(db common.Database, hash common.Hash) *types.Block {
	data, _ := db.Get(append(blockHashPre, hash[:]...))
	if len(data) == 0 {
		return nil
	}
	var block types.StorageBlock
	if err := rlp.Decode(bytes.NewReader(data), &block); err != nil {
		glog.V(logger.Error).Infof("invalid block RLP for hash %x: %v", hash, err)
		return nil
	}
	return (*types.Block)(&block)
}

// GetReceipt returns a receipt by hash
func GetReceipt(db common.Database, txHash common.Hash) *types.Receipt {
	data, _ := db.Get(append(receiptsPre, txHash[:]...))
	if len(data) == 0 {
		return nil
	}

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

func putReceipts(db common.Database, hash common.Hash, receipts types.Receipts) error {
	storageReceipts := make([]*types.ReceiptForStorage, len(receipts))
	for i, receipt := range receipts {
		storageReceipts[i] = (*types.ReceiptForStorage)(receipt)
	}

	bytes, err := rlp.EncodeToBytes(storageReceipts)
	if err != nil {
		return err
	}

	db.Put(append(receiptsPre, hash[:]...), bytes)

	return nil
}