mirror of
https://gitlab.com/pulsechaincom/erigon-pulse.git
synced 2024-12-24 12:37:16 +00:00
a0bf2ea7e7
Added calling mechanism and return value parsing
164 lines
4.7 KiB
Go
164 lines
4.7 KiB
Go
// Copyright 2015 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 (
|
|
"encoding/json"
|
|
"fmt"
|
|
"io"
|
|
"math"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/logger"
|
|
"github.com/ethereum/go-ethereum/logger/glog"
|
|
)
|
|
|
|
// Executer is an executer method for performing state executions. It takes one
|
|
// argument which is the input data and expects output data to be returned as
|
|
// multiple 32 byte word length concatenated slice
|
|
type Executer func(datain []byte) []byte
|
|
|
|
// The ABI holds information about a contract's context and available
|
|
// invokable methods. It will allow you to type check function calls and
|
|
// packs data accordingly.
|
|
type ABI struct {
|
|
Methods map[string]Method
|
|
}
|
|
|
|
// JSON returns a parsed ABI interface and error if it failed.
|
|
func JSON(reader io.Reader) (ABI, error) {
|
|
dec := json.NewDecoder(reader)
|
|
|
|
var abi ABI
|
|
if err := dec.Decode(&abi); err != nil {
|
|
return ABI{}, err
|
|
}
|
|
|
|
return abi, nil
|
|
}
|
|
|
|
// tests, tests whether the given input would result in a successful
|
|
// call. Checks argument list count and matches input to `input`.
|
|
func (abi ABI) pack(name string, args ...interface{}) ([]byte, error) {
|
|
method := abi.Methods[name]
|
|
|
|
var ret []byte
|
|
for i, a := range args {
|
|
input := method.Inputs[i]
|
|
|
|
packed, err := input.Type.pack(a)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("`%s` %v", name, err)
|
|
}
|
|
ret = append(ret, packed...)
|
|
|
|
}
|
|
|
|
return ret, nil
|
|
}
|
|
|
|
// Pack the given method name to conform the ABI. Method call's data
|
|
// will consist of method_id, args0, arg1, ... argN. Method id consists
|
|
// of 4 bytes and arguments are all 32 bytes.
|
|
// Method ids are created from the first 4 bytes of the hash of the
|
|
// methods string signature. (signature = baz(uint32,string32))
|
|
func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error) {
|
|
method, exist := abi.Methods[name]
|
|
if !exist {
|
|
return nil, fmt.Errorf("method '%s' not found", name)
|
|
}
|
|
|
|
// start with argument count match
|
|
if len(args) != len(method.Inputs) {
|
|
return nil, fmt.Errorf("argument count mismatch: %d for %d", len(args), len(method.Inputs))
|
|
}
|
|
|
|
arguments, err := abi.pack(name, args...)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Set function id
|
|
packed := abi.Methods[name].Id()
|
|
packed = append(packed, arguments...)
|
|
|
|
return packed, nil
|
|
}
|
|
|
|
// toGoType parses the input and casts it to the proper type defined by the ABI
|
|
// argument in t.
|
|
func toGoType(t Argument, input []byte) interface{} {
|
|
switch t.Type.T {
|
|
case IntTy:
|
|
return common.BytesToBig(input)
|
|
case UintTy:
|
|
return common.BytesToBig(input)
|
|
case BoolTy:
|
|
return common.BytesToBig(input).Uint64() > 0
|
|
case AddressTy:
|
|
return common.BytesToAddress(input)
|
|
case HashTy:
|
|
return common.BytesToHash(input)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Call executes a call and attemps to parse the return values and returns it as
|
|
// an interface. It uses the executer method to perform the actual call since
|
|
// the abi knows nothing of the lower level calling mechanism.
|
|
//
|
|
// Call supports all abi types and includes multiple return values. When only
|
|
// one item is returned a single interface{} will be returned, if a contract
|
|
// method returns multiple values an []interface{} slice is returned.
|
|
func (abi ABI) Call(executer Executer, name string, args ...interface{}) interface{} {
|
|
callData, err := abi.Pack(name, args...)
|
|
if err != nil {
|
|
glog.V(logger.Debug).Infoln("pack error:", err)
|
|
return nil
|
|
}
|
|
|
|
output := executer(callData)
|
|
|
|
method := abi.Methods[name]
|
|
ret := make([]interface{}, int(math.Max(float64(len(method.Outputs)), float64(len(output)/32))))
|
|
for i := 0; i < len(ret); i += 32 {
|
|
index := i / 32
|
|
ret[index] = toGoType(method.Outputs[index], output[i:i+32])
|
|
}
|
|
|
|
// return single interface
|
|
if len(ret) == 1 {
|
|
return ret[0]
|
|
}
|
|
|
|
return ret
|
|
}
|
|
|
|
func (abi *ABI) UnmarshalJSON(data []byte) error {
|
|
var methods []Method
|
|
if err := json.Unmarshal(data, &methods); err != nil {
|
|
return err
|
|
}
|
|
|
|
abi.Methods = make(map[string]Method)
|
|
for _, method := range methods {
|
|
abi.Methods[method.Name] = method
|
|
}
|
|
|
|
return nil
|
|
}
|