コード例 #1
0
ファイル: txindex.go プロジェクト: decred/dcrd
// dbFetchTxIndexEntry uses an existing database transaction to fetch the block
// region for the provided transaction hash from the transaction index.  When
// there is no entry for the provided hash, nil will be returned for the both
// the region and the error.
func dbFetchTxIndexEntry(dbTx database.Tx, txHash chainhash.Hash) (*database.BlockRegion, error) {
	// Load the record from the database and return now if it doesn't exist.
	txIndex := dbTx.Metadata().Bucket(txIndexKey)
	serializedData := txIndex.Get(txHash[:])
	if len(serializedData) == 0 {
		return nil, nil
	}

	// Ensure the serialized data has enough bytes to properly deserialize.
	if len(serializedData) < 12 {
		return nil, database.Error{
			ErrorCode: database.ErrCorruption,
			Description: fmt.Sprintf("corrupt transaction index "+
				"entry for %s", txHash),
		}
	}

	// Load the block hash associated with the block ID.
	hash, err := dbFetchBlockHashBySerializedID(dbTx, serializedData[0:4])
	if err != nil {
		return nil, database.Error{
			ErrorCode: database.ErrCorruption,
			Description: fmt.Sprintf("corrupt transaction index "+
				"entry for %s: %v", txHash, err),
		}
	}

	// Deserialize the final entry.
	region := database.BlockRegion{Hash: &chainhash.Hash{}}
	copy(region.Hash[:], hash[:])
	region.Offset = byteOrder.Uint32(serializedData[4:8])
	region.Len = byteOrder.Uint32(serializedData[8:12])

	return &region, nil
}
コード例 #2
0
ファイル: addrindex.go プロジェクト: decred/dcrd
// deserializeAddrIndexEntry decodes the passed serialized byte slice into the
// provided region struct according to the format described in detail above and
// uses the passed block hash fetching function in order to conver the block ID
// to the associated block hash.
func deserializeAddrIndexEntry(serialized []byte, region *database.BlockRegion, fetchBlockHash fetchBlockHashFunc) error {
	// Ensure there are enough bytes to decode.
	if len(serialized) < txEntrySize {
		return errDeserialize("unexpected end of data")
	}

	hash, err := fetchBlockHash(serialized[0:4])
	if err != nil {
		return err
	}
	region.Hash = &hash
	region.Offset = byteOrder.Uint32(serialized[4:8])
	region.Len = byteOrder.Uint32(serialized[8:12])
	return nil
}