account/abi: implements event parsing

Implementation of basic event parsing and its input types. This
separates methods and events and fixes an issue with go type parsing and
validation.
This commit is contained in:
Jeffrey Wilcke 2016-01-27 08:38:53 +01:00
parent d951ff300e
commit bddf8f76c8
6 changed files with 174 additions and 31 deletions

@ -37,6 +37,7 @@ type Executer func(datain []byte) []byte
// packs data accordingly.
type ABI struct {
Methods map[string]Method
Events map[string]Event
}
// JSON returns a parsed ABI interface and error if it failed.
@ -149,14 +150,37 @@ func (abi ABI) Call(executer Executer, name string, args ...interface{}) interfa
}
func (abi *ABI) UnmarshalJSON(data []byte) error {
var methods []Method
if err := json.Unmarshal(data, &methods); err != nil {
var fields []struct {
Type string
Name string
Const bool
Indexed bool
Inputs []Argument
Outputs []Argument
}
if err := json.Unmarshal(data, &fields); err != nil {
return err
}
abi.Methods = make(map[string]Method)
for _, method := range methods {
abi.Methods[method.Name] = method
abi.Events = make(map[string]Event)
for _, field := range fields {
switch field.Type {
// empty defaults to function according to the abi spec
case "function", "":
abi.Methods[field.Name] = Method{
Name: field.Name,
Const: field.Const,
Inputs: field.Inputs,
Outputs: field.Outputs,
}
case "event":
abi.Events[field.Name] = Event{
Name: field.Name,
Inputs: field.Inputs,
}
}
}
return nil

@ -31,25 +31,25 @@ import (
const jsondata = `
[
{ "name" : "balance", "const" : true },
{ "name" : "send", "const" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] }
{ "type" : "function", "name" : "balance", "const" : true },
{ "type" : "function", "name" : "send", "const" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] }
]`
const jsondata2 = `
[
{ "name" : "balance", "const" : true },
{ "name" : "send", "const" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] },
{ "name" : "test", "const" : false, "inputs" : [ { "name" : "number", "type" : "uint32" } ] },
{ "name" : "string", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "string" } ] },
{ "name" : "bool", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "bool" } ] },
{ "name" : "address", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "address" } ] },
{ "name" : "string32", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "string32" } ] },
{ "name" : "uint64[2]", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[2]" } ] },
{ "name" : "uint64[]", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[]" } ] },
{ "name" : "foo", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" } ] },
{ "name" : "bar", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" }, { "name" : "string", "type" : "uint16" } ] },
{ "name" : "slice", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32[2]" } ] },
{ "name" : "slice256", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint256[2]" } ] }
{ "type" : "function", "name" : "balance", "const" : true },
{ "type" : "function", "name" : "send", "const" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] },
{ "type" : "function", "name" : "test", "const" : false, "inputs" : [ { "name" : "number", "type" : "uint32" } ] },
{ "type" : "function", "name" : "string", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "string" } ] },
{ "type" : "function", "name" : "bool", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "bool" } ] },
{ "type" : "function", "name" : "address", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "address" } ] },
{ "type" : "function", "name" : "string32", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "string32" } ] },
{ "type" : "function", "name" : "uint64[2]", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[2]" } ] },
{ "type" : "function", "name" : "uint64[]", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[]" } ] },
{ "type" : "function", "name" : "foo", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" } ] },
{ "type" : "function", "name" : "bar", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" }, { "name" : "string", "type" : "uint16" } ] },
{ "type" : "function", "name" : "slice", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32[2]" } ] },
{ "type" : "function", "name" : "slice256", "const" : false, "inputs" : [ { "name" : "inputs", "type" : "uint256[2]" } ] }
]`
func TestType(t *testing.T) {
@ -96,7 +96,7 @@ func TestReader(t *testing.T) {
},
"send": Method{
"send", false, []Argument{
Argument{"amount", Uint256},
Argument{"amount", Uint256, false},
}, nil,
},
},
@ -238,7 +238,7 @@ func TestTestAddress(t *testing.T) {
func TestMethodSignature(t *testing.T) {
String, _ := NewType("string")
String32, _ := NewType("string32")
m := Method{"foo", false, []Argument{Argument{"bar", String32}, Argument{"baz", String}}, nil}
m := Method{"foo", false, []Argument{Argument{"bar", String32, false}, Argument{"baz", String, false}}, nil}
exp := "foo(string32,string)"
if m.Sig() != exp {
t.Error("signature mismatch", exp, "!=", m.Sig())
@ -250,7 +250,7 @@ func TestMethodSignature(t *testing.T) {
}
uintt, _ := NewType("uint")
m = Method{"foo", false, []Argument{Argument{"bar", uintt}}, nil}
m = Method{"foo", false, []Argument{Argument{"bar", uintt, false}}, nil}
exp = "foo(uint256)"
if m.Sig() != exp {
t.Error("signature mismatch", exp, "!=", m.Sig())
@ -367,8 +367,8 @@ func ExampleJSON() {
func TestBytes(t *testing.T) {
const definition = `[
{ "name" : "balance", "const" : true, "inputs" : [ { "name" : "address", "type" : "bytes20" } ] },
{ "name" : "send", "const" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] }
{ "type" : "function", "name" : "balance", "const" : true, "inputs" : [ { "name" : "address", "type" : "bytes20" } ] },
{ "type" : "function", "name" : "send", "const" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] }
]`
abi, err := JSON(strings.NewReader(definition))
@ -396,10 +396,8 @@ func TestBytes(t *testing.T) {
func TestReturn(t *testing.T) {
const definition = `[
{ "name" : "balance", "const" : true, "inputs" : [], "outputs" : [ { "name": "", "type": "hash" } ] },
{ "name" : "name", "const" : true, "inputs" : [], "outputs" : [ { "name": "", "type": "address" } ] }
]`
{ "type" : "function", "name" : "balance", "const" : true, "inputs" : [], "outputs" : [ { "name": "", "type": "hash" } ] },
{ "type" : "function", "name" : "name", "const" : true, "inputs" : [], "outputs" : [ { "name": "", "type": "address" } ] }]`
abi, err := JSON(strings.NewReader(definition))
if err != nil {
@ -424,3 +422,39 @@ func TestReturn(t *testing.T) {
t.Errorf("expected type common.Address, got %T", r)
}
}
func TestDefaultFunctionParsing(t *testing.T) {
const definition = `[{ "name" : "balance" }]`
abi, err := JSON(strings.NewReader(definition))
if err != nil {
t.Fatal(err)
}
if _, ok := abi.Methods["balance"]; !ok {
t.Error("expected 'balance' to be present")
}
}
func TestBareEvents(t *testing.T) {
const definition = `[
{ "type" : "event", "name" : "balance" },
{ "type" : "event", "name" : "name" }]`
abi, err := JSON(strings.NewReader(definition))
if err != nil {
t.Fatal(err)
}
if len(abi.Events) != 2 {
t.Error("expected 2 events")
}
if _, ok := abi.Events["balance"]; !ok {
t.Error("expected 'balance' event to be present")
}
if _, ok := abi.Events["name"]; !ok {
t.Error("expected 'name' event to be present")
}
}

@ -24,8 +24,9 @@ import (
// Argument holds the name of the argument and the corresponding type.
// Types are used when packing and testing arguments.
type Argument struct {
Name string
Type Type
Name string
Type Type
Indexed bool // indexed is only used by events
}
func (a *Argument) UnmarshalJSON(data []byte) error {

44
accounts/abi/event.go Normal file

@ -0,0 +1,44 @@
// 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 (
"fmt"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
)
// Event is an event potentially triggered by the EVM's LOG mechanism. The Event
// holds type information (inputs) about the yielded output
type Event struct {
Name string
Inputs []Argument
}
// Id returns the canonical representation of the event's signature used by the
// abi definition to identify event names and types.
func (e Event) Id() common.Hash {
types := make([]string, len(e.Inputs))
i := 0
for _, input := range e.Inputs {
types[i] = input.Type.String()
i++
}
return common.BytesToHash(crypto.Sha3([]byte(fmt.Sprintf("%v(%v)", e.Name, strings.Join(types, ",")))))
}

@ -0,0 +1,40 @@
package abi
import (
"strings"
"testing"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
)
func TestEventId(t *testing.T) {
var table = []struct {
definition string
expectations map[string]common.Hash
}{
{
definition: `[
{ "type" : "event", "name" : "balance", "inputs": [{ "name" : "in", "type": "uint" }] },
{ "type" : "event", "name" : "check", "inputs": [{ "name" : "t", "type": "address" }, { "name": "b", "type": "uint256" }] }
]`,
expectations: map[string]common.Hash{
"balance": crypto.Sha3Hash([]byte("balance(uint256)")),
"check": crypto.Sha3Hash([]byte("check(address,uint256)")),
},
},
}
for _, test := range table {
abi, err := JSON(strings.NewReader(test.definition))
if err != nil {
t.Fatal(err)
}
for name, event := range abi.Events {
if event.Id() != test.expectations[name] {
t.Errorf("expected id to be %x, got %x", test.expectations[name], event.Id())
}
}
}
}

@ -218,5 +218,5 @@ func (t Type) pack(v interface{}) ([]byte, error) {
}
}
return nil, fmt.Errorf("ABI: bad input given %T", value.Kind())
return nil, fmt.Errorf("ABI: bad input given %v", value.Kind())
}