accounts/abi: add another unpack interface

accounts/abi/abi.go

@@ -136,11 +136,11 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
 
 // MethodById looks up a method by the 4-byte id
 // returns nil if none found
-func (abi *ABI) MethodById(sigdata []byte) *Method {
+func (abi *ABI) MethodById(sigdata []byte) (*Method, error){
 	for _, method := range abi.Methods {
 		if bytes.Equal(method.Id(), sigdata[:4]) {
-			return &method
+			return &method, nil
 		}
 	}
-	return nil
+	return nil, fmt.Errorf("ABI spec does not contain method signature in data: 0x%x", sigdata[:4])
 }

accounts/abi/abi_test.go

@@ -689,7 +689,11 @@ func TestABI_MethodById(t *testing.T) {
 	}
 	for name, m := range abi.Methods {
 		a := fmt.Sprintf("%v", m)
-		b := fmt.Sprintf("%v", abi.MethodById(m.Id()))
+		m2,err := abi.MethodById(m.Id())
+		if err != nil {
+			t.Fatal(err)
+		}
+		b := fmt.Sprintf("%v", m2)
 		if a != b {
 			t.Errorf("Method %v (id %v) not 'findable' by id in ABI", name, common.ToHex(m.Id()))
 		}

accounts/abi/argument.go

@@ -67,6 +67,16 @@ func (arguments Arguments) LengthNonIndexed() int {
 	return out
 }
 
+func (arguments Arguments) NonIndexed() Arguments{
+	var ret []Argument
+	for _,arg := range arguments{
+		if !arg.Indexed{
+			ret = append(ret, arg)
+		}
+	}
+	return ret
+}
+
 // isTuple returns true for non-atomic constructs, like (uint,uint) or uint[]
 func (arguments Arguments) isTuple() bool {
 	return len(arguments) > 1
@@ -114,14 +124,9 @@ func (arguments Arguments) unpackTuple(v interface{}, output []byte) error {
 	// `j` counts the number of complex types.
 	// both `i` and `j` are used to to correctly compute `data` offset.
 
-	i, j := -1, 0
+	j := 0
-	for _, arg := range arguments {
+	for i, arg := range arguments.NonIndexed() {
 
-		if arg.Indexed {
-			// can't read, continue
-			continue
-		}
-		i++
 		marshalledValue, err := toGoType((i+j)*32, arg.Type, output)
 		if err != nil {
 			return err
@@ -178,7 +183,6 @@ func (arguments Arguments) unpackAtomic(v interface{}, output []byte) error {
 	}
 
 	value := valueOf.Elem()
-
 	marshalledValue, err := toGoType(0, arg.Type, output)
 	if err != nil {
 		return err
@@ -186,7 +190,44 @@ func (arguments Arguments) unpackAtomic(v interface{}, output []byte) error {
 	return set(value, reflect.ValueOf(marshalledValue), arg)
 }
 
-// Unpack performs the operation Go format -> Hexdata
+// UnpackValues can be used to unpack ABI-encoded hexdata according to the ABI-specification,
+// without supplying a struct to unpack into. Instead, this method returns a list containing the
+// values. An atomic argument will be a list with one element.
+func (arguments Arguments) UnpackValues(data []byte) ([]interface{}, error){
+
+	retval := make([]interface{},0,arguments.LengthNonIndexed())
+
+	virtualArgs := 0
+
+	for index,arg:= range arguments.NonIndexed(){
+
+		marshalledValue, err := toGoType((index + virtualArgs) * 32, arg.Type, data)
+
+		if arg.Type.T == ArrayTy {
+			//If we have a static array, like [3]uint256, these are coded as
+			// just like uint256,uint256,uint256.
+			// This means that we need to add two 'virtual' arguments when
+			// we count the index from now on
+
+			virtualArgs += arg.Type.Size - 1
+		}
+
+		if err != nil{
+			return nil, err
+		}
+		retval = append(retval, marshalledValue)
+	}
+	return retval, nil
+}
+
+// UnpackValues performs the operation Go format -> Hexdata
+// It is the semantic opposite of UnpackValues
+func (arguments Arguments) PackValues(args []interface{}) ([]byte, error) {
+	return arguments.Pack(args...)
+}
+
+
+// Pack performs the operation Go format -> Hexdata
 func (arguments Arguments) Pack(args ...interface{}) ([]byte, error) {
 	// Make sure arguments match up and pack them
 	abiArgs := arguments

accounts/abi/unpack_test.go

@@ -130,7 +130,7 @@ var unpackTests = []unpackTest{
 	{
 		def:  `[{"type": "bytes32"}]`,
 		enc:  "0100000000000000000000000000000000000000000000000000000000000000",
-		want: common.HexToHash("0100000000000000000000000000000000000000000000000000000000000000"),
+		want: [32]byte{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
 	},
 	{
 		def:  `[{"type": "function"}]`,

accounts/abi/unpackv2_test.go

@@ -0,0 +1,336 @@
+// 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 (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"math/big"
+	"reflect"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+func TestUnpackV2(t *testing.T) {
+	for i, test := range unpackTests {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			def := fmt.Sprintf(`[{ "name" : "method", "outputs": %s}]`, test.def)
+			abi, err := JSON(strings.NewReader(def))
+			if err != nil {
+				t.Fatalf("invalid ABI definition %s: %v", def, err)
+			}
+			encb, err := hex.DecodeString(test.enc)
+			if err != nil {
+				t.Fatalf("invalid hex: %s" + test.enc)
+			}
+			out, err := abi.Methods["method"].Outputs.UnpackValues(encb)
+
+			if err != nil {
+				t.Fatal(err)
+			}
+			if len(test.err) != 0 {
+				// The new stuff doesn't have these types of errors
+				return
+			}
+			if !reflect.DeepEqual(test.want, out[0]) {
+				t.Errorf("test %d (%v) failed: expected %v, got %v", i, test.def, test.want, out[0])
+			}
+		})
+	}
+}
+
+
+func TestMultiReturnWithArrayV2(t *testing.T) {
+	const definition = `[{"name" : "multi", "outputs": [{"type": "uint64[3]"}, {"type": "uint64"}]}]`
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Fatal(err)
+	}
+	buff := new(bytes.Buffer)
+	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000900000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000007"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000006"))
+
+	out, err := abi.Methods["multi"].Outputs.UnpackValues(buff.Bytes())
+
+	ret1Exp := [3]uint64{9, 8, 7}
+	ret2Exp := uint64(6)
+
+	if !reflect.DeepEqual(out[0], ret1Exp) {
+		t.Error("array result", out[0], "!= Expected", ret1Exp)
+	}
+	if out[1] != ret2Exp {
+		t.Error("int result", out[1], "!= Expected", ret2Exp)
+	}
+}
+
+func TestUnmarshalV2(t *testing.T) {
+	const definition = `[
+	{ "name" : "int", "constant" : false, "outputs": [ { "type": "uint256" } ] },
+	{ "name" : "bool", "constant" : false, "outputs": [ { "type": "bool" } ] },
+	{ "name" : "bytes", "constant" : false, "outputs": [ { "type": "bytes" } ] },
+	{ "name" : "fixed", "constant" : false, "outputs": [ { "type": "bytes32" } ] },
+	{ "name" : "multi", "constant" : false, "outputs": [ { "type": "bytes" }, { "type": "bytes" } ] },
+	{ "name" : "intArraySingle", "constant" : false, "outputs": [ { "type": "uint256[3]" } ] },
+	{ "name" : "addressSliceSingle", "constant" : false, "outputs": [ { "type": "address[]" } ] },
+	{ "name" : "addressSliceDouble", "constant" : false, "outputs": [ { "name": "a", "type": "address[]" }, { "name": "b", "type": "address[]" } ] },
+	{ "name" : "mixedBytes", "constant" : true, "outputs": [ { "name": "a", "type": "bytes" }, { "name": "b", "type": "bytes32" } ] }]`
+
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Fatal(err)
+	}
+	buff := new(bytes.Buffer)
+
+	// marshall mixed bytes (mixedBytes)
+	p0Exp := common.Hex2Bytes("01020000000000000000")
+	p1Exp := common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000ddeeff")
+
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000ddeeff"))
+	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000a"))
+	buff.Write(common.Hex2Bytes("0102000000000000000000000000000000000000000000000000000000000000"))
+
+	mixedBytes, err := abi.Methods["mixedBytes"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Error(err)
+	} else {
+		p0 := mixedBytes[0].([]byte)
+		p1 := mixedBytes[1].([32]byte)
+		if !bytes.Equal(p0, p0Exp) {
+			t.Errorf("unexpected value unpacked: want %x, got %x", p0Exp, p0)
+		}
+
+		if !bytes.Equal(p1[:], p1Exp) {
+			t.Errorf("unexpected value unpacked: want %x, got %x", p1Exp, p1)
+		}
+	}
+
+	// marshal int
+	integer, err := abi.Methods["int"].Outputs.UnpackValues(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001"))
+	if err != nil {
+		t.Error(err)
+	}
+	if len(integer) == 0 {
+		t.Error("Expected one integer")
+	}
+	intval := integer[0].(*big.Int)
+	if intval == nil || intval.Cmp(big.NewInt(1)) != 0 {
+		t.Error("expected Int to be 1 got", intval)
+	}
+
+	// marshal bool
+	boolreturns, err := abi.Methods["bool"].Outputs.UnpackValues(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001"))
+	if err != nil {
+		t.Error(err)
+	}
+	boolval := boolreturns[0].(bool)
+	if !boolval {
+		t.Error("expected Bool to be true")
+	}
+
+	// marshal dynamic bytes max length 32
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
+	bytesOut := common.RightPadBytes([]byte("hello"), 32)
+	buff.Write(bytesOut)
+
+	bytesreturns, err := abi.Methods["bytes"].Outputs.UnpackValues(buff.Bytes())
+
+	if err != nil {
+		t.Error(err)
+	}
+	bytesval := bytesreturns[0].([]byte)
+	if !bytes.Equal(bytesval, bytesOut) {
+		t.Errorf("expected %x got %x", bytesOut, bytesval)
+	}
+
+	// marshall dynamic bytes max length 64
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040"))
+	bytesOut = common.RightPadBytes([]byte("hello"), 64)
+	buff.Write(bytesOut)
+
+	bytesreturns, err = abi.Methods["bytes"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Error(err)
+	}
+	bytesval = bytesreturns[0].([]byte)
+	if !bytes.Equal(bytesval, bytesOut) {
+		t.Errorf("expected %x got %x", bytesOut, bytesval)
+	}
+
+	// marshall dynamic bytes max length 64
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
+	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000003f"))
+	bytesOut = common.RightPadBytes([]byte("hello"), 64)
+	buff.Write(bytesOut)
+
+	bytesreturns, err = abi.Methods["bytes"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Error(err)
+	}
+	bytesval = bytesreturns[0].([]byte)
+
+	if !bytes.Equal(bytesval, bytesOut[:len(bytesOut)-1]) {
+		t.Errorf("expected %x got %x", bytesOut[:len(bytesOut)-1], bytesval)
+	}
+	// marshal dynamic bytes output empty  (nil)
+	bytesreturns, err = abi.Methods["bytes"].Outputs.UnpackValues(nil)
+	if err == nil {
+		t.Error("expected error")
+	}
+	// marshal dynamic bytes output empty
+	buff.Reset()
+	bytesreturns, err = abi.Methods["bytes"].Outputs.UnpackValues(buff.Bytes())
+	if err == nil {
+		t.Error("expected error")
+	}
+
+	// marshal dynamic bytes length 5
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000005"))
+	buff.Write(common.RightPadBytes([]byte("hello"), 32))
+
+	bytesreturns, err = abi.Methods["bytes"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Error(err)
+	}
+	bytesval = bytesreturns[0].([]byte)
+
+	if !bytes.Equal(bytesval, []byte("hello")) {
+		t.Errorf("expected %x got %x", bytesOut, bytesval)
+	}
+
+	// marshal dynamic bytes length 5
+	buff.Reset()
+	buff.Write(common.RightPadBytes([]byte("hello"), 32))
+
+	hashreturns, err := abi.Methods["fixed"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Error(err)
+	}
+	hashval := hashreturns[0].([32]byte)
+
+	helloHash := common.BytesToHash(common.RightPadBytes([]byte("hello"), 32))
+	if common.Hash(hashval) != helloHash {
+		t.Errorf("Expected %x to equal %x", hashval, helloHash)
+	}
+
+	// marshal error
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
+
+	bytesreturns, err = abi.Methods["bytes"].Outputs.UnpackValues(buff.Bytes())
+	if err == nil {
+		// Error abi: cannot marshal in to go slice: offset 32 would go over slice boundary (len=64)
+		t.Error("expected error")
+	}
+	bytesreturns, err = abi.Methods["multi"].Outputs.UnpackValues(make([]byte, 64))
+
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000003"))
+	// marshal int array
+
+	intArrayReturns, err := abi.Methods["intArraySingle"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Error(err)
+	}
+	intArray := intArrayReturns[0].([3]*big.Int)
+
+	var testAgainstIntArray = [3]*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)}
+
+	for i, intval := range intArray {
+		if intval.Cmp(testAgainstIntArray[i]) != 0 {
+			t.Errorf("expected %v, got %v", testAgainstIntArray[i], intval)
+		}
+	}
+	// marshal address slice
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020")) // offset
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // size
+	buff.Write(common.Hex2Bytes("0000000000000000000000000100000000000000000000000000000000000000"))
+
+	outAddrReturns, err := abi.Methods["addressSliceSingle"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Fatal("didn't expect error:", err)
+	}
+	outAddr := outAddrReturns[0].([]common.Address)
+	if len(outAddr) != 1 {
+		t.Fatal("expected 1 item, got", len(outAddr))
+	}
+
+	if outAddr[0] != (common.Address{1}) {
+		t.Errorf("expected %x, got %x", common.Address{1}, outAddr[0])
+	}
+
+	// marshal multiple address slice
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040")) // offset
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000080")) // offset
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // size
+	buff.Write(common.Hex2Bytes("0000000000000000000000000100000000000000000000000000000000000000"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // size
+	buff.Write(common.Hex2Bytes("0000000000000000000000000200000000000000000000000000000000000000"))
+	buff.Write(common.Hex2Bytes("0000000000000000000000000300000000000000000000000000000000000000"))
+
+	outAddrStructReturns, err := abi.Methods["addressSliceDouble"].Outputs.UnpackValues(buff.Bytes())
+	if err != nil {
+		t.Fatal("didn't expect error:", err)
+	}
+	A := outAddrStructReturns[0].([]common.Address)
+	B := outAddrStructReturns[1].([]common.Address)
+
+	if len(A) != 1 {
+		t.Fatal("expected 1 item, got", len(A))
+	}
+
+	if A[0] != (common.Address{1}) {
+		t.Errorf("expected %x, got %x", common.Address{1}, A[0])
+	}
+
+	if len(B) != 2 {
+		t.Fatal("expected 1 item, got", len(B))
+	}
+
+	if B[0] != (common.Address{2}) {
+		t.Errorf("expected %x, got %x", common.Address{2}, B[0])
+	}
+	if B[1] != (common.Address{3}) {
+		t.Errorf("expected %x, got %x", common.Address{3}, B[1])
+	}
+
+	// marshal invalid address slice
+	buff.Reset()
+	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000100"))
+
+	err = abi.Unpack(&outAddr, "addressSliceSingle", buff.Bytes())
+	_, err = abi.Methods["addressSliceSingle"].Outputs.UnpackValues(buff.Bytes())
+	if err == nil {
+		t.Fatal("expected error:", err)
+	}
+
+}