1 files changed, 348 insertions, 0 deletions
diff --git a/accounts/abi/type.go b/accounts/abi/type.go
new file mode 100644
index 0000000..597d314
--- /dev/null
+++ b/accounts/abi/type.go
@@ -0,0 +1,348 @@
+// 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 (
+	"errors"
+	"fmt"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// Type enumerator
+const (
+	IntTy byte = iota
+	UintTy
+	BoolTy
+	StringTy
+	SliceTy
+	ArrayTy
+	TupleTy
+	AddressTy
+	FixedBytesTy
+	BytesTy
+	HashTy
+	FixedPointTy
+	FunctionTy
+)
+
+// Type is the reflection of the supported argument type
+type Type struct {
+	Elem *Type
+	Kind reflect.Kind
+	Type reflect.Type
+	Size int
+	T    byte // Our own type checking
+
+	stringKind string // holds the unparsed string for deriving signatures
+
+	// Tuple relative fields
+	TupleElems    []*Type  // Type information of all tuple fields
+	TupleRawNames []string // Raw field name of all tuple fields
+}
+
+var (
+	// typeRegex parses the abi sub types
+	typeRegex = regexp.MustCompile("([a-zA-Z]+)(([0-9]+)(x([0-9]+))?)?")
+)
+
+// NewType creates a new reflection type of abi type given in t.
+func NewType(t string, components []ArgumentMarshaling) (typ Type, err error) {
+	// check that array brackets are equal if they exist
+	if strings.Count(t, "[") != strings.Count(t, "]") {
+		return Type{}, fmt.Errorf("invalid arg type in abi")
+	}
+	typ.stringKind = t
+
+	// if there are brackets, get ready to go into slice/array mode and
+	// recursively create the type
+	if strings.Count(t, "[") != 0 {
+		i := strings.LastIndex(t, "[")
+		// recursively embed the type
+		embeddedType, err := NewType(t[:i], components)
+		if err != nil {
+			return Type{}, err
+		}
+		// grab the last cell and create a type from there
+		sliced := t[i:]
+		// grab the slice size with regexp
+		re := regexp.MustCompile("[0-9]+")
+		intz := re.FindAllString(sliced, -1)
+
+		if len(intz) == 0 {
+			// is a slice
+			typ.T = SliceTy
+			typ.Kind = reflect.Slice
+			typ.Elem = &embeddedType
+			typ.Type = reflect.SliceOf(embeddedType.Type)
+			typ.stringKind = embeddedType.stringKind + sliced
+		} else if len(intz) == 1 {
+			// is a array
+			typ.T = ArrayTy
+			typ.Kind = reflect.Array
+			typ.Elem = &embeddedType
+			typ.Size, err = strconv.Atoi(intz[0])
+			if err != nil {
+				return Type{}, fmt.Errorf("abi: error parsing variable size: %v", err)
+			}
+			typ.Type = reflect.ArrayOf(typ.Size, embeddedType.Type)
+			typ.stringKind = embeddedType.stringKind + sliced
+		} else {
+			return Type{}, fmt.Errorf("invalid formatting of array type")
+		}
+		return typ, err
+	}
+	// parse the type and size of the abi-type.
+	matches := typeRegex.FindAllStringSubmatch(t, -1)
+	if len(matches) == 0 {
+		return Type{}, fmt.Errorf("invalid type '%v'", t)
+	}
+	parsedType := matches[0]
+
+	// varSize is the size of the variable
+	var varSize int
+	if len(parsedType[3]) > 0 {
+		var err error
+		varSize, err = strconv.Atoi(parsedType[2])
+		if err != nil {
+			return Type{}, fmt.Errorf("abi: error parsing variable size: %v", err)
+		}
+	} else {
+		if parsedType[0] == "uint" || parsedType[0] == "int" {
+			// this should fail because it means that there's something wrong with
+			// the abi type (the compiler should always format it to the size...always)
+			return Type{}, fmt.Errorf("unsupported arg type: %s", t)
+		}
+	}
+	// varType is the parsed abi type
+	switch varType := parsedType[1]; varType {
+	case "int":
+		typ.Kind, typ.Type = reflectIntKindAndType(false, varSize)
+		typ.Size = varSize
+		typ.T = IntTy
+	case "uint":
+		typ.Kind, typ.Type = reflectIntKindAndType(true, varSize)
+		typ.Size = varSize
+		typ.T = UintTy
+	case "bool":
+		typ.Kind = reflect.Bool
+		typ.T = BoolTy
+		typ.Type = reflect.TypeOf(bool(false))
+	case "address":
+		typ.Kind = reflect.Array
+		typ.Type = addressT
+		typ.Size = 20
+		typ.T = AddressTy
+	case "string":
+		typ.Kind = reflect.String
+		typ.Type = reflect.TypeOf("")
+		typ.T = StringTy
+	case "bytes":
+		if varSize == 0 {
+			typ.T = BytesTy
+			typ.Kind = reflect.Slice
+			typ.Type = reflect.SliceOf(reflect.TypeOf(byte(0)))
+		} else {
+			typ.T = FixedBytesTy
+			typ.Kind = reflect.Array
+			typ.Size = varSize
+			typ.Type = reflect.ArrayOf(varSize, reflect.TypeOf(byte(0)))
+		}
+	case "tuple":
+		var (
+			fields     []reflect.StructField
+			elems      []*Type
+			names      []string
+			expression string // canonical parameter expression
+		)
+		expression += "("
+		for idx, c := range components {
+			cType, err := NewType(c.Type, c.Components)
+			if err != nil {
+				return Type{}, err
+			}
+			if ToCamelCase(c.Name) == "" {
+				return Type{}, errors.New("abi: purely anonymous or underscored field is not supported")
+			}
+			fields = append(fields, reflect.StructField{
+				Name: ToCamelCase(c.Name), // reflect.StructOf will panic for any exported field.
+				Type: cType.Type,
+				Tag:  reflect.StructTag("json:\"" + c.Name + "\""),
+			})
+			elems = append(elems, &cType)
+			names = append(names, c.Name)
+			expression += cType.stringKind
+			if idx != len(components)-1 {
+				expression += ","
+			}
+		}
+		expression += ")"
+		typ.Kind = reflect.Struct
+		typ.Type = reflect.StructOf(fields)
+		typ.TupleElems = elems
+		typ.TupleRawNames = names
+		typ.T = TupleTy
+		typ.stringKind = expression
+	case "function":
+		typ.Kind = reflect.Array
+		typ.T = FunctionTy
+		typ.Size = 24
+		typ.Type = reflect.ArrayOf(24, reflect.TypeOf(byte(0)))
+	default:
+		return Type{}, fmt.Errorf("unsupported arg type: %s", t)
+	}
+
+	return
+}
+
+// String implements Stringer
+func (t Type) String() (out string) {
+	return t.stringKind
+}
+
+func (t Type) pack(v reflect.Value) ([]byte, error) {
+	// dereference pointer first if it's a pointer
+	v = indirect(v)
+	if err := typeCheck(t, v); err != nil {
+		return nil, err
+	}
+
+	switch t.T {
+	case SliceTy, ArrayTy:
+		var ret []byte
+
+		if t.requiresLengthPrefix() {
+			// append length
+			ret = append(ret, packNum(reflect.ValueOf(v.Len()))...)
+		}
+
+		// calculate offset if any
+		offset := 0
+		offsetReq := isDynamicType(*t.Elem)
+		if offsetReq {
+			offset = getTypeSize(*t.Elem) * v.Len()
+		}
+		var tail []byte
+		for i := 0; i < v.Len(); i++ {
+			val, err := t.Elem.pack(v.Index(i))
+			if err != nil {
+				return nil, err
+			}
+			if !offsetReq {
+				ret = append(ret, val...)
+				continue
+			}
+			ret = append(ret, packNum(reflect.ValueOf(offset))...)
+			offset += len(val)
+			tail = append(tail, val...)
+		}
+		return append(ret, tail...), nil
+	case TupleTy:
+		// (T1,...,Tk) for k >= 0 and any types T1, …, Tk
+		// enc(X) = head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(k))
+		// where X = (X(1), ..., X(k)) and head and tail are defined for Ti being a static
+		// type as
+		//     head(X(i)) = enc(X(i)) and tail(X(i)) = "" (the empty string)
+		// and as
+		//     head(X(i)) = enc(len(head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(i-1))))
+		//     tail(X(i)) = enc(X(i))
+		// otherwise, i.e. if Ti is a dynamic type.
+		fieldmap, err := mapArgNamesToStructFields(t.TupleRawNames, v)
+		if err != nil {
+			return nil, err
+		}
+		// Calculate prefix occupied size.
+		offset := 0
+		for _, elem := range t.TupleElems {
+			offset += getTypeSize(*elem)
+		}
+		var ret, tail []byte
+		for i, elem := range t.TupleElems {
+			field := v.FieldByName(fieldmap[t.TupleRawNames[i]])
+			if !field.IsValid() {
+				return nil, fmt.Errorf("field %s for tuple not found in the given struct", t.TupleRawNames[i])
+			}
+			val, err := elem.pack(field)
+			if err != nil {
+				return nil, err
+			}
+			if isDynamicType(*elem) {
+				ret = append(ret, packNum(reflect.ValueOf(offset))...)
+				tail = append(tail, val...)
+				offset += len(val)
+			} else {
+				ret = append(ret, val...)
+			}
+		}
+		return append(ret, tail...), nil
+
+	default:
+		return packElement(t, v), nil
+	}
+}
+
+// requireLengthPrefix returns whether the type requires any sort of length
+// prefixing.
+func (t Type) requiresLengthPrefix() bool {
+	return t.T == StringTy || t.T == BytesTy || t.T == SliceTy
+}
+
+// isDynamicType returns true if the type is dynamic.
+// The following types are called “dynamic”:
+// * bytes
+// * string
+// * T[] for any T
+// * T[k] for any dynamic T and any k >= 0
+// * (T1,...,Tk) if Ti is dynamic for some 1 <= i <= k
+func isDynamicType(t Type) bool {
+	if t.T == TupleTy {
+		for _, elem := range t.TupleElems {
+			if isDynamicType(*elem) {
+				return true
+			}
+		}
+		return false
+	}
+	return t.T == StringTy || t.T == BytesTy || t.T == SliceTy || (t.T == ArrayTy && isDynamicType(*t.Elem))
+}
+
+// getTypeSize returns the size that this type needs to occupy.
+// We distinguish static and dynamic types. Static types are encoded in-place
+// and dynamic types are encoded at a separately allocated location after the
+// current block.
+// So for a static variable, the size returned represents the size that the
+// variable actually occupies.
+// For a dynamic variable, the returned size is fixed 32 bytes, which is used
+// to store the location reference for actual value storage.
+func getTypeSize(t Type) int {
+	if t.T == ArrayTy && !isDynamicType(*t.Elem) {
+		// Recursively calculate type size if it is a nested array
+		if t.Elem.T == ArrayTy {
+			return t.Size * getTypeSize(*t.Elem)
+		}
+		return t.Size * 32
+	} else if t.T == TupleTy && !isDynamicType(t) {
+		total := 0
+		for _, elem := range t.TupleElems {
+			total += getTypeSize(*elem)
+		}
+		return total
+	}
+	return 32
+}