ipld-eth-server/libraries/shared/storage/utils/decoder.go
2019-07-18 13:30:04 -05:00

94 lines
2.7 KiB
Go

// VulcanizeDB
// Copyright © 2019 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package utils
import (
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/common"
)
func Decode(row StorageDiffRow, metadata StorageValueMetadata) (interface{}, error) {
switch metadata.Type {
case Uint256:
return decodeUint256(row.StorageValue.Bytes()), nil
case Uint48:
return decodeUint48(row.StorageValue.Bytes()), nil
case Address:
return decodeAddress(row.StorageValue.Bytes()), nil
case Bytes32:
return row.StorageValue.Hex(), nil
case PackedSlot:
return decodePackedSlot(row.StorageValue.Bytes(), metadata.PackedTypes), nil
default:
panic(fmt.Sprintf("can't decode unknown type: %d", metadata.Type))
}
}
func decodeUint256(raw []byte) string {
n := big.NewInt(0).SetBytes(raw)
return n.String()
}
func decodeUint48(raw []byte) string {
n := big.NewInt(0).SetBytes(raw)
return n.String()
}
func decodeAddress(raw []byte) string {
return common.BytesToAddress(raw).Hex()
}
//this may need to return a slice of strings, a string for each item
func decodePackedSlot(raw []byte, packedTypes map[int]ValueType) []string{
storageSlot := raw
var results []string
//the reason we're using a map and not a slice is that golang doesn't guarantee the order of a slice
for _, valueType := range packedTypes {
lengthOfStorageSlot := len(storageSlot)
lengthOfItem := getLengthOfItem(valueType)
itemStartingIndex := lengthOfStorageSlot - lengthOfItem
value := storageSlot[itemStartingIndex:]
decodedValue := decodeIndividualItems(value, valueType)
results = append(results, decodedValue)
//pop last item off slot before moving on
storageSlot = storageSlot[0:itemStartingIndex]
}
return results
}
func decodeIndividualItems(itemBytes []byte, valueType ValueType) string {
switch valueType {
case Uint48:
return decodeUint48(itemBytes)
default:
panic(fmt.Sprintf("can't decode unknown type: %d", valueType))
}
}
func getLengthOfItem(valueType ValueType) int{
switch valueType {
case Uint48:
return 6
default:
panic(fmt.Sprintf("ValueType %d not recognized", valueType))
}
}