// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package bind
import (
"errors"
"fmt"
"math/big"
"reflect"
"github.com/ethereum/go-ethereum/accounts/abi"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
)
// makeTopics converts a filter query argument list into a filter topic set.
func makeTopics(query ...[]interface{}) ([][]common.Hash, error) {
topics := make([][]common.Hash, len(query))
for i, filter := range query {
for _, rule := range filter {
var topic common.Hash
// Try to generate the topic based on simple types
switch rule := rule.(type) {
case common.Hash:
copy(topic[:], rule[:])
case common.Address:
copy(topic[common.HashLength-common.AddressLength:], rule[:])
case *big.Int:
blob := rule.Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case bool:
if rule {
topic[common.HashLength-1] = 1
}
case int8:
blob := big.NewInt(int64(rule)).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case int16:
blob := big.NewInt(int64(rule)).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case int32:
blob := big.NewInt(int64(rule)).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case int64:
blob := big.NewInt(rule).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case uint8:
blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case uint16:
blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case uint32:
blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case uint64:
blob := new(big.Int).SetUint64(rule).Bytes()
copy(topic[common.HashLength-len(blob):], blob)
case string:
hash := crypto.Keccak256Hash([]byte(rule))
copy(topic[:], hash[:])
case []byte:
hash := crypto.Keccak256Hash(rule)
copy(topic[:], hash[:])
default:
// Attempt to generate the topic from funky types
val := reflect.ValueOf(rule)
switch {
case val.Kind() == reflect.Array && reflect.TypeOf(rule).Elem().Kind() == reflect.Uint8:
reflect.Copy(reflect.ValueOf(topic[common.HashLength-val.Len():]), val)
default:
return nil, fmt.Errorf("unsupported indexed type: %T", rule)
}
}
topics[i] = append(topics[i], topic)
}
}
return topics, nil
}
// Big batch of reflect types for topic reconstruction.
var (
reflectHash = reflect.TypeOf(common.Hash{})
reflectAddress = reflect.TypeOf(common.Address{})
reflectBigInt = reflect.TypeOf(new(big.Int))
)
// parseTopics converts the indexed topic fields into actual log field values.
//
// Note, dynamic types cannot be reconstructed since they get mapped to Keccak256
// hashes as the topic value!
func parseTopics(out interface{}, fields abi.Arguments, topics []common.Hash) error {
// Sanity check that the fields and topics match up
if len(fields) != len(topics) {
return errors.New("topic/field count mismatch")
}
// Iterate over all the fields and reconstruct them from topics
for _, arg := range fields {
if !arg.Indexed {
return errors.New("non-indexed field in topic reconstruction")
}
field := reflect.ValueOf(out).Elem().FieldByName(capitalise(arg.Name))
// Try to parse the topic back into the fields based on primitive types
switch field.Kind() {
case reflect.Bool:
if topics[0][common.HashLength-1] == 1 {
field.Set(reflect.ValueOf(true))
}
case reflect.Int8:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(int8(num.Int64())))
case reflect.Int16:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(int16(num.Int64())))
case reflect.Int32:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(int32(num.Int64())))
case reflect.Int64:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(num.Int64()))
case reflect.Uint8:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(uint8(num.Uint64())))
case reflect.Uint16:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(uint16(num.Uint64())))
case reflect.Uint32:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(uint32(num.Uint64())))
case reflect.Uint64:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(num.Uint64()))
default:
// Ran out of plain primitive types, try custom types
switch field.Type() {
case reflectHash: // Also covers all dynamic types
field.Set(reflect.ValueOf(topics[0]))
case reflectAddress:
var addr common.Address
copy(addr[:], topics[0][common.HashLength-common.AddressLength:])
field.Set(reflect.ValueOf(addr))
case reflectBigInt:
num := new(big.Int).SetBytes(topics[0][:])
field.Set(reflect.ValueOf(num))
default:
// Ran out of custom types, try the crazies
switch {
case arg.Type.T == abi.FixedBytesTy:
reflect.Copy(field, reflect.ValueOf(topics[0][common.HashLength-arg.Type.Size:]))
default:
return fmt.Errorf("unsupported indexed type: %v", arg.Type)
}
}
}
topics = topics[1:]
}
return nil
}
