diff options
Diffstat (limited to 'accounts/abi/bind/topics.go')
| -rw-r--r-- | accounts/abi/bind/topics.go | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/accounts/abi/bind/topics.go b/accounts/abi/bind/topics.go new file mode 100644 index 000000000..600dfcda9 --- /dev/null +++ b/accounts/abi/bind/topics.go @@ -0,0 +1,189 @@ +// 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 +} |