plugeth/accounts/abi/type.go
2016-04-04 20:30:58 +02:00

239 lines
6.3 KiB
Go

// 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 (
"fmt"
"reflect"
"regexp"
"strconv"
"github.com/ethereum/go-ethereum/common"
)
const (
IntTy byte = iota
UintTy
BoolTy
StringTy
SliceTy
AddressTy
FixedBytesTy
BytesTy
HashTy
RealTy
)
// Type is the reflection of the supported argument type
type Type struct {
Kind reflect.Kind
Type reflect.Type
Size int
T byte // Our own type checking
stringKind string // holds the unparsed string for deriving signatures
}
// NewType returns a fully parsed Type given by the input string or an error if it can't be parsed.
//
// Strings can be in the format of:
//
// Input = Type [ "[" [ Number ] "]" ] Name .
// Type = [ "u" ] "int" [ Number ] .
//
// Examples:
//
// string int uint real
// string32 int8 uint8 uint[]
// address int256 uint256 real[2]
func NewType(t string) (typ Type, err error) {
// 1. full string 2. type 3. (opt.) is slice 4. (opt.) size
freg, err := regexp.Compile("([a-zA-Z0-9]+)(\\[([0-9]*)?\\])?")
if err != nil {
return Type{}, err
}
res := freg.FindAllStringSubmatch(t, -1)[0]
var (
isslice bool
size int
)
switch {
case res[3] != "":
// err is ignored. Already checked for number through the regexp
size, _ = strconv.Atoi(res[3])
isslice = true
case res[2] != "":
isslice = true
size = -1
case res[0] == "":
return Type{}, fmt.Errorf("type parse error for `%s`", t)
}
treg, err := regexp.Compile("([a-zA-Z]+)([0-9]*)?")
if err != nil {
return Type{}, err
}
parsedType := treg.FindAllStringSubmatch(res[1], -1)[0]
vsize, _ := strconv.Atoi(parsedType[2])
vtype := parsedType[1]
// substitute canonical representation
if vsize == 0 && (vtype == "int" || vtype == "uint") {
vsize = 256
t += "256"
}
switch vtype {
case "int":
typ.Kind = reflect.Ptr
typ.Type = big_t
typ.Size = 256
typ.T = IntTy
case "uint":
typ.Kind = reflect.Ptr
typ.Type = ubig_t
typ.Size = 256
typ.T = UintTy
case "bool":
typ.Kind = reflect.Bool
typ.T = BoolTy
case "real": // TODO
typ.Kind = reflect.Invalid
case "address":
typ.Kind = reflect.Slice
typ.Type = address_t
typ.Size = 20
typ.T = AddressTy
case "string":
typ.Kind = reflect.String
typ.Size = -1
typ.T = StringTy
if vsize > 0 {
typ.Size = 32
}
case "hash":
typ.Kind = reflect.Slice
typ.Size = 32
typ.Type = hash_t
typ.T = HashTy
case "bytes":
typ.Kind = reflect.Slice
typ.Type = byte_ts
typ.Size = vsize
if vsize == 0 {
typ.T = BytesTy
} else {
typ.T = FixedBytesTy
}
default:
return Type{}, fmt.Errorf("unsupported arg type: %s", t)
}
// if the type is a slice we must set Kind to a reflect.Slice
// so that serialisation can be determined based on this kind.
if isslice {
typ.Kind = reflect.Slice
typ.Size = size
}
typ.stringKind = t
return
}
func (t Type) String() (out string) {
return t.stringKind
}
// packBytesSlice packs the given bytes as [L, V] as the canonical representation
// bytes slice
func packBytesSlice(bytes []byte, l int) []byte {
len := packNum(reflect.ValueOf(l), UintTy)
return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
}
// Test the given input parameter `v` and checks if it matches certain
// criteria
// * Big integers are checks for ptr types and if the given value is
// assignable
// * Integer are checked for size
// * Strings, addresses and bytes are checks for type and size
func (t Type) pack(v interface{}) ([]byte, error) {
value := reflect.ValueOf(v)
switch kind := value.Kind(); kind {
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
if t.Type != ubig_t {
return nil, fmt.Errorf("type mismatch: %s for %T", t.Type, v)
}
return packNum(value, t.T), nil
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
if t.Type != ubig_t {
return nil, fmt.Errorf("type mismatch: %s for %T", t.Type, v)
}
return packNum(value, t.T), nil
case reflect.Ptr:
// If the value is a ptr do a assign check (only used by
// big.Int for now)
if t.Type == ubig_t && value.Type() != ubig_t {
return nil, fmt.Errorf("type mismatch: %s for %T", t.Type, v)
}
return packNum(value, t.T), nil
case reflect.String:
if t.Size > -1 && value.Len() > t.Size {
return nil, fmt.Errorf("%v out of bound. %d for %d", value.Kind(), value.Len(), t.Size)
}
return packBytesSlice([]byte(value.String()), value.Len()), nil
case reflect.Slice:
// Byte slice is a special case, it gets treated as a single value
if t.T == BytesTy {
return packBytesSlice(value.Bytes(), value.Len()), nil
}
if t.Size > -1 && value.Len() > t.Size {
return nil, fmt.Errorf("%v out of bound. %d for %d", value.Kind(), value.Len(), t.Size)
}
// Signed / Unsigned check
if value.Type() == big_t && (t.T != IntTy && isSigned(value)) || (t.T == UintTy && isSigned(value)) {
return nil, fmt.Errorf("slice of incompatible types.")
}
var packed []byte
for i := 0; i < value.Len(); i++ {
val, err := t.pack(value.Index(i).Interface())
if err != nil {
return nil, err
}
packed = append(packed, val...)
}
return packBytesSlice(packed, value.Len()), nil
case reflect.Bool:
if value.Bool() {
return common.LeftPadBytes(common.Big1.Bytes(), 32), nil
} else {
return common.LeftPadBytes(common.Big0.Bytes(), 32), nil
}
case reflect.Array:
if v, ok := value.Interface().(common.Address); ok {
return common.LeftPadBytes(v[:], 32), nil
} else if v, ok := value.Interface().(common.Hash); ok {
return v[:], nil
}
}
return nil, fmt.Errorf("ABI: bad input given %v", value.Kind())
}