Merge pull request ethereum#15731 from holiman/revamp_abi

accounts/abi refactor

Author: holiman

accounts/abi/abi.go

@@ -17,6 +17,7 @@
 package abi
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -50,25 +51,25 @@ func JSON(reader io.Reader) (ABI, error) {
 // methods string signature. (signature = baz(uint32,string32))
 func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error) {
 	// Fetch the ABI of the requested method
-	var method Method
-
 	if name == "" {
-		method = abi.Constructor
-	} else {
-		m, exist := abi.Methods[name]
-		if !exist {
-			return nil, fmt.Errorf("method '%s' not found", name)
+		// constructor
+		arguments, err := abi.Constructor.Inputs.Pack(args...)
+		if err != nil {
+			return nil, err
 		}
-		method = m
+		return arguments, nil
+
+	}
+	method, exist := abi.Methods[name]
+	if !exist {
+		return nil, fmt.Errorf("method '%s' not found", name)
 	}
-	arguments, err := method.pack(args...)
+
+	arguments, err := method.Inputs.Pack(args...)
 	if err != nil {
 		return nil, err
 	}
 	// Pack up the method ID too if not a constructor and return
-	if name == "" {
-		return arguments, nil
-	}
 	return append(method.Id(), arguments...), nil
 }
 
@@ -77,28 +78,20 @@ func (abi ABI) Unpack(v interface{}, name string, output []byte) (err error) {
 	if len(output) == 0 {
 		return fmt.Errorf("abi: unmarshalling empty output")
 	}
-
 	// since there can't be naming collisions with contracts and events,
 	// we need to decide whether we're calling a method or an event
-	var unpack unpacker
 	if method, ok := abi.Methods[name]; ok {
 		if len(output)%32 != 0 {
 			return fmt.Errorf("abi: improperly formatted output")
 		}
-		unpack = method
+		return method.Outputs.Unpack(v, output)
 	} else if event, ok := abi.Events[name]; ok {
-		unpack = event
-	} else {
-		return fmt.Errorf("abi: could not locate named method or event.")
-	}
-
-	// requires a struct to unpack into for a tuple return...
-	if unpack.isTupleReturn() {
-		return unpack.tupleUnpack(v, output)
+		return event.Inputs.Unpack(v, output)
 	}
-	return unpack.singleUnpack(v, output)
+	return fmt.Errorf("abi: could not locate named method or event")
 }
 
+// UnmarshalJSON implements json.Unmarshaler interface
 func (abi *ABI) UnmarshalJSON(data []byte) error {
 	var fields []struct {
 		Type      string
@@ -141,3 +134,14 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
 
 	return nil
 }
+
+// MethodById looks up a method by the 4-byte id
+// returns nil if none found
+func (abi *ABI) MethodById(sigdata []byte) *Method {
+	for _, method := range abi.Methods {
+		if bytes.Equal(method.Id(), sigdata[:4]) {
+			return &method
+		}
+	}
+	return nil
+}

accounts/abi/abi_test.go

@@ -22,10 +22,11 @@ import (
 	"fmt"
 	"log"
 	"math/big"
-	"reflect"
 	"strings"
 	"testing"
 
+	"reflect"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 )
@@ -75,9 +76,24 @@ func TestReader(t *testing.T) {
 	}
 
 	// deep equal fails for some reason
-	t.Skip()
-	if !reflect.DeepEqual(abi, exp) {
-		t.Errorf("\nabi: %v\ndoes not match exp: %v", abi, exp)
+	for name, expM := range exp.Methods {
+		gotM, exist := abi.Methods[name]
+		if !exist {
+			t.Errorf("Missing expected method %v", name)
+		}
+		if !reflect.DeepEqual(gotM, expM) {
+			t.Errorf("\nGot abi method: \n%v\ndoes not match expected method\n%v", gotM, expM)
+		}
+	}
+
+	for name, gotM := range abi.Methods {
+		expM, exist := exp.Methods[name]
+		if !exist {
+			t.Errorf("Found extra method %v", name)
+		}
+		if !reflect.DeepEqual(gotM, expM) {
+			t.Errorf("\nGot abi method: \n%v\ndoes not match expected method\n%v", gotM, expM)
+		}
 	}
 }
 
@@ -641,3 +657,42 @@ func TestUnpackEvent(t *testing.T) {
 		t.Logf("len(data): %d; received event: %+v", len(data), ev)
 	}
 }
+
+func TestABI_MethodById(t *testing.T) {
+	const abiJSON = `[
+		{"type":"function","name":"receive","constant":false,"inputs":[{"name":"memo","type":"bytes"}],"outputs":[],"payable":true,"stateMutability":"payable"},
+		{"type":"event","name":"received","anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}]},
+		{"type":"function","name":"fixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr","type":"uint256[2]"}]},
+		{"type":"function","name":"fixedArrBytes","constant":true,"inputs":[{"name":"str","type":"bytes"},{"name":"fixedArr","type":"uint256[2]"}]},
+		{"type":"function","name":"mixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr","type":"uint256[2]"},{"name":"dynArr","type":"uint256[]"}]},
+		{"type":"function","name":"doubleFixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr1","type":"uint256[2]"},{"name":"fixedArr2","type":"uint256[3]"}]},
+		{"type":"function","name":"multipleMixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr1","type":"uint256[2]"},{"name":"dynArr","type":"uint256[]"},{"name":"fixedArr2","type":"uint256[3]"}]},
+		{"type":"function","name":"balance","constant":true},
+		{"type":"function","name":"send","constant":false,"inputs":[{"name":"amount","type":"uint256"}]},
+		{"type":"function","name":"test","constant":false,"inputs":[{"name":"number","type":"uint32"}]},
+		{"type":"function","name":"string","constant":false,"inputs":[{"name":"inputs","type":"string"}]},
+		{"type":"function","name":"bool","constant":false,"inputs":[{"name":"inputs","type":"bool"}]},
+		{"type":"function","name":"address","constant":false,"inputs":[{"name":"inputs","type":"address"}]},
+		{"type":"function","name":"uint64[2]","constant":false,"inputs":[{"name":"inputs","type":"uint64[2]"}]},
+		{"type":"function","name":"uint64[]","constant":false,"inputs":[{"name":"inputs","type":"uint64[]"}]},
+		{"type":"function","name":"foo","constant":false,"inputs":[{"name":"inputs","type":"uint32"}]},
+		{"type":"function","name":"bar","constant":false,"inputs":[{"name":"inputs","type":"uint32"},{"name":"string","type":"uint16"}]},
+		{"type":"function","name":"_slice","constant":false,"inputs":[{"name":"inputs","type":"uint32[2]"}]},
+		{"type":"function","name":"__slice256","constant":false,"inputs":[{"name":"inputs","type":"uint256[2]"}]},
+		{"type":"function","name":"sliceAddress","constant":false,"inputs":[{"name":"inputs","type":"address[]"}]},
+		{"type":"function","name":"sliceMultiAddress","constant":false,"inputs":[{"name":"a","type":"address[]"},{"name":"b","type":"address[]"}]}
+	]
+`
+	abi, err := JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for name, m := range abi.Methods {
+		a := fmt.Sprintf("%v", m)
+		b := fmt.Sprintf("%v", abi.MethodById(m.Id()))
+		if a != b {
+			t.Errorf("Method %v (id %v) not 'findable' by id in ABI", name, common.ToHex(m.Id()))
+		}
+	}
+
+}

accounts/abi/argument.go

@@ -19,6 +19,8 @@ package abi
 import (
 	"encoding/json"
 	"fmt"
+	"reflect"
+	"strings"
 )
 
 // Argument holds the name of the argument and the corresponding type.
@@ -29,7 +31,10 @@ type Argument struct {
 	Indexed bool // indexed is only used by events
 }
 
-func (a *Argument) UnmarshalJSON(data []byte) error {
+type Arguments []Argument
+
+// UnmarshalJSON implements json.Unmarshaler interface
+func (argument *Argument) UnmarshalJSON(data []byte) error {
 	var extarg struct {
 		Name    string
 		Type    string
@@ -40,12 +45,180 @@ func (a *Argument) UnmarshalJSON(data []byte) error {
 		return fmt.Errorf("argument json err: %v", err)
 	}
 
-	a.Type, err = NewType(extarg.Type)
+	argument.Type, err = NewType(extarg.Type)
 	if err != nil {
 		return err
 	}
-	a.Name = extarg.Name
-	a.Indexed = extarg.Indexed
+	argument.Name = extarg.Name
+	argument.Indexed = extarg.Indexed
 
 	return nil
 }
+
+// LengthNonIndexed returns the number of arguments when not counting 'indexed' ones. Only events
+// can ever have 'indexed' arguments, it should always be false on arguments for method input/output
+func (arguments Arguments) LengthNonIndexed() int {
+	out := 0
+	for _, arg := range arguments {
+		if !arg.Indexed {
+			out++
+		}
+	}
+	return out
+}
+
+// isTuple returns true for non-atomic constructs, like (uint,uint) or uint[]
+func (arguments Arguments) isTuple() bool {
+	return len(arguments) > 1
+}
+
+// Unpack performs the operation hexdata -> Go format
+func (arguments Arguments) Unpack(v interface{}, data []byte) error {
+	if arguments.isTuple() {
+		return arguments.unpackTuple(v, data)
+	}
+	return arguments.unpackAtomic(v, data)
+}
+
+func (arguments Arguments) unpackTuple(v interface{}, output []byte) error {
+	// make sure the passed value is arguments pointer
+	valueOf := reflect.ValueOf(v)
+	if reflect.Ptr != valueOf.Kind() {
+		return fmt.Errorf("abi: Unpack(non-pointer %T)", v)
+	}
+
+	var (
+		value = valueOf.Elem()
+		typ   = value.Type()
+		kind  = value.Kind()
+	)
+
+	if err := requireUnpackKind(value, typ, kind, arguments); err != nil {
+		return err
+	}
+	// `i` counts the nonindexed arguments.
+	// `j` counts the number of complex types.
+	// both `i` and `j` are used to to correctly compute `data` offset.
+
+	i, j := -1, 0
+	for _, arg := range arguments {
+
+		if arg.Indexed {
+			// can't read, continue
+			continue
+		}
+		i++
+		marshalledValue, err := toGoType((i+j)*32, arg.Type, output)
+		if err != nil {
+			return err
+		}
+
+		if arg.Type.T == ArrayTy {
+			// combined index ('i' + 'j') need to be adjusted only by size of array, thus
+			// we need to decrement 'j' because 'i' was incremented
+			j += arg.Type.Size - 1
+		}
+
+		reflectValue := reflect.ValueOf(marshalledValue)
+
+		switch kind {
+		case reflect.Struct:
+			for j := 0; j < typ.NumField(); j++ {
+				field := typ.Field(j)
+				// TODO read tags: `abi:"fieldName"`
+				if field.Name == strings.ToUpper(arg.Name[:1])+arg.Name[1:] {
+					if err := set(value.Field(j), reflectValue, arg); err != nil {
+						return err
+					}
+				}
+			}
+		case reflect.Slice, reflect.Array:
+			if value.Len() < i {
+				return fmt.Errorf("abi: insufficient number of arguments for unpack, want %d, got %d", len(arguments), value.Len())
+			}
+			v := value.Index(i)
+			if err := requireAssignable(v, reflectValue); err != nil {
+				return err
+			}
+
+			if err := set(v.Elem(), reflectValue, arg); err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("abi:[2] cannot unmarshal tuple in to %v", typ)
+		}
+	}
+	return nil
+}
+
+// unpackAtomic unpacks ( hexdata -> go ) a single value
+func (arguments Arguments) unpackAtomic(v interface{}, output []byte) error {
+	// make sure the passed value is arguments pointer
+	valueOf := reflect.ValueOf(v)
+	if reflect.Ptr != valueOf.Kind() {
+		return fmt.Errorf("abi: Unpack(non-pointer %T)", v)
+	}
+	arg := arguments[0]
+	if arg.Indexed {
+		return fmt.Errorf("abi: attempting to unpack indexed variable into element.")
+	}
+
+	value := valueOf.Elem()
+
+	marshalledValue, err := toGoType(0, arg.Type, output)
+	if err != nil {
+		return err
+	}
+	return set(value, reflect.ValueOf(marshalledValue), arg)
+}
+
+// Unpack performs the operation Go format -> Hexdata
+func (arguments Arguments) Pack(args ...interface{}) ([]byte, error) {
+	// Make sure arguments match up and pack them
+	abiArgs := arguments
+	if len(args) != len(abiArgs) {
+		return nil, fmt.Errorf("argument count mismatch: %d for %d", len(args), len(abiArgs))
+	}
+
+	// variable input is the output appended at the end of packed
+	// output. This is used for strings and bytes types input.
+	var variableInput []byte
+
+	// input offset is the bytes offset for packed output
+	inputOffset := 0
+	for _, abiArg := range abiArgs {
+		if abiArg.Type.T == ArrayTy {
+			inputOffset += (32 * abiArg.Type.Size)
+		} else {
+			inputOffset += 32
+		}
+	}
+
+	var ret []byte
+	for i, a := range args {
+		input := abiArgs[i]
+		// pack the input
+		packed, err := input.Type.pack(reflect.ValueOf(a))
+		if err != nil {
+			return nil, err
+		}
+
+		// check for a slice type (string, bytes, slice)
+		if input.Type.requiresLengthPrefix() {
+			// calculate the offset
+			offset := inputOffset + len(variableInput)
+			// set the offset
+			ret = append(ret, packNum(reflect.ValueOf(offset))...)
+			// Append the packed output to the variable input. The variable input
+			// will be appended at the end of the input.
+			variableInput = append(variableInput, packed...)
+		} else {
+			// append the packed value to the input
+			ret = append(ret, packed...)
+		}
+	}
+	// append the variable input at the end of the packed input
+	ret = append(ret, variableInput...)
+
+	return ret, nil
+}