Golang Database.Delete方法代碼示例

// upgradeChainDatabase ensures that the chain database stores block split into
// separate header and body entries.
func upgradeChainDatabase(db ethdb.Database) error {
	// Short circuit if the head block is stored already as separate header and body
	data, err := db.Get([]byte("LastBlock"))
	if err != nil {
		return nil
	}
	head := common.BytesToHash(data)

	if block := core.GetBlockByHashOld(db, head); block == nil {
		return nil
	}
	// At least some of the database is still the old format, upgrade (skip the head block!)
	glog.V(logger.Info).Info("Old database detected, upgrading...")

	if db, ok := db.(*ethdb.LDBDatabase); ok {
		blockPrefix := []byte("block-hash-")
		for it := db.NewIterator(); it.Next(); {
			// Skip anything other than a combined block
			if !bytes.HasPrefix(it.Key(), blockPrefix) {
				continue
			}
			// Skip the head block (merge last to signal upgrade completion)
			if bytes.HasSuffix(it.Key(), head.Bytes()) {
				continue
			}
			// Load the block, split and serialize (order!)
			block := core.GetBlockByHashOld(db, common.BytesToHash(bytes.TrimPrefix(it.Key(), blockPrefix)))

			if err := core.WriteTd(db, block.Hash(), block.DeprecatedTd()); err != nil {
				return err
			}
			if err := core.WriteBody(db, block.Hash(), block.Body()); err != nil {
				return err
			}
			if err := core.WriteHeader(db, block.Header()); err != nil {
				return err
			}
			if err := db.Delete(it.Key()); err != nil {
				return err
			}
		}
		// Lastly, upgrade the head block, disabling the upgrade mechanism
		current := core.GetBlockByHashOld(db, head)

		if err := core.WriteTd(db, current.Hash(), current.DeprecatedTd()); err != nil {
			return err
		}
		if err := core.WriteBody(db, current.Hash(), current.Body()); err != nil {
			return err
		}
		if err := core.WriteHeader(db, current.Header()); err != nil {
			return err
		}
	}
	return nil
}

// DeleteReceipt removes all receipt data associated with a transaction hash.
func DeleteReceipt(db ethdb.Database, hash common.Hash) {
	db.Delete(append(receiptsPrefix, hash.Bytes()...))
}

// DeleteTransaction removes all transaction data associated with a hash.
func DeleteTransaction(db ethdb.Database, hash common.Hash) {
	db.Delete(hash.Bytes())
	db.Delete(append(hash.Bytes(), txMetaSuffix...))
}

// DeleteTd removes all block total difficulty data associated with a hash.
func DeleteTd(db ethdb.Database, hash common.Hash) {
	db.Delete(append(append(blockPrefix, hash.Bytes()...), tdSuffix...))
}

// DeleteCanonicalHash removes the number to hash canonical mapping.
func DeleteCanonicalHash(db ethdb.Database, number uint64) {
	db.Delete(append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...))
}

func DeleteTransaction(db ethdb.Database, txHash common.Hash) {
	db.Delete(txHash[:])
}

// Delete a receipts from the database
func DeleteReceipt(db ethdb.Database, txHash common.Hash) {
	db.Delete(append(receiptsPre, txHash[:]...))
}