github.com/0xsequence/ethkit@v1.25.0/go-ethereum/accounts/abi/error.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package abi
    18  
    19  import (
    20  	"bytes"
    21  	"errors"
    22  	"fmt"
    23  	"strings"
    24  
    25  	"github.com/0xsequence/ethkit/go-ethereum/common"
    26  	"github.com/0xsequence/ethkit/go-ethereum/crypto"
    27  )
    28  
    29  type Error struct {
    30  	Name   string
    31  	Inputs Arguments
    32  	str    string
    33  
    34  	// Sig contains the string signature according to the ABI spec.
    35  	// e.g.	 error foo(uint32 a, int b) = "foo(uint32,int256)"
    36  	// Please note that "int" is substitute for its canonical representation "int256"
    37  	Sig string
    38  
    39  	// ID returns the canonical representation of the error's signature used by the
    40  	// abi definition to identify event names and types.
    41  	ID common.Hash
    42  }
    43  
    44  func NewError(name string, inputs Arguments) Error {
    45  	// sanitize inputs to remove inputs without names
    46  	// and precompute string and sig representation.
    47  	names := make([]string, len(inputs))
    48  	types := make([]string, len(inputs))
    49  	for i, input := range inputs {
    50  		if input.Name == "" {
    51  			inputs[i] = Argument{
    52  				Name:    fmt.Sprintf("arg%d", i),
    53  				Indexed: input.Indexed,
    54  				Type:    input.Type,
    55  			}
    56  		} else {
    57  			inputs[i] = input
    58  		}
    59  		// string representation
    60  		names[i] = fmt.Sprintf("%v %v", input.Type, inputs[i].Name)
    61  		if input.Indexed {
    62  			names[i] = fmt.Sprintf("%v indexed %v", input.Type, inputs[i].Name)
    63  		}
    64  		// sig representation
    65  		types[i] = input.Type.String()
    66  	}
    67  
    68  	str := fmt.Sprintf("error %v(%v)", name, strings.Join(names, ", "))
    69  	sig := fmt.Sprintf("%v(%v)", name, strings.Join(types, ","))
    70  	id := common.BytesToHash(crypto.Keccak256([]byte(sig)))
    71  
    72  	return Error{
    73  		Name:   name,
    74  		Inputs: inputs,
    75  		str:    str,
    76  		Sig:    sig,
    77  		ID:     id,
    78  	}
    79  }
    80  
    81  func (e *Error) String() string {
    82  	return e.str
    83  }
    84  
    85  func (e *Error) Unpack(data []byte) (interface{}, error) {
    86  	if len(data) < 4 {
    87  		return "", errors.New("invalid data for unpacking")
    88  	}
    89  	if !bytes.Equal(data[:4], e.ID[:4]) {
    90  		return "", errors.New("invalid data for unpacking")
    91  	}
    92  	return e.Inputs.Unpack(data[4:])
    93  }