go-ethereum/accounts/abi/error.go

93 lines
2.7 KiB
Go

// Copyright 2016 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 abi
import (
"bytes"
"fmt"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
)
type Error struct {
Name string
Inputs Arguments
str string
// Sig contains the string signature according to the ABI spec.
// e.g. error foo(uint32 a, int b) = "foo(uint32,int256)"
// Please note that "int" is substitute for its canonical representation "int256"
Sig string
// ID returns the canonical representation of the error's signature used by the
// abi definition to identify event names and types.
ID common.Hash
}
func NewError(name string, inputs Arguments) Error {
// sanitize inputs to remove inputs without names
// and precompute string and sig representation.
names := make([]string, len(inputs))
types := make([]string, len(inputs))
for i, input := range inputs {
if input.Name == "" {
inputs[i] = Argument{
Name: fmt.Sprintf("arg%d", i),
Indexed: input.Indexed,
Type: input.Type,
}
} else {
inputs[i] = input
}
// string representation
names[i] = fmt.Sprintf("%v %v", input.Type, inputs[i].Name)
if input.Indexed {
names[i] = fmt.Sprintf("%v indexed %v", input.Type, inputs[i].Name)
}
// sig representation
types[i] = input.Type.String()
}
str := fmt.Sprintf("error %v(%v)", name, strings.Join(names, ", "))
sig := fmt.Sprintf("%v(%v)", name, strings.Join(types, ","))
id := common.BytesToHash(crypto.Keccak256([]byte(sig)))
return Error{
Name: name,
Inputs: inputs,
str: str,
Sig: sig,
ID: id,
}
}
func (e Error) String() string {
return e.str
}
func (e *Error) Unpack(data []byte) (interface{}, error) {
if len(data) < 4 {
return "", fmt.Errorf("insufficient data for unpacking: have %d, want at least 4", len(data))
}
if !bytes.Equal(data[:4], e.ID[:4]) {
return "", fmt.Errorf("invalid identifier, have %#x want %#x", data[:4], e.ID[:4])
}
return e.Inputs.Unpack(data[4:])
}