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Diffstat (limited to 'accounts/abi/type.go')
-rw-r--r-- | accounts/abi/type.go | 348 |
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 +} |