package ethutil
import (
"bytes"
"fmt"
"math/big"
"reflect"
)
// Data values are returned by the rlp decoder. The data values represents
// one item within the rlp data structure. It's responsible for all the casting
// It always returns something valid
type Value struct {
Val interface{}
kind reflect.Value
}
func (val *Value) String() string {
return fmt.Sprintf("%q", val.Val)
}
func NewValue(val interface{}) *Value {
return &Value{Val: val}
}
func (val *Value) Type() reflect.Kind {
return reflect.TypeOf(val.Val).Kind()
}
func (val *Value) IsNil() bool {
return val.Val == nil
}
func (val *Value) Len() int {
//return val.kind.Len()
if data, ok := val.Val.([]interface{}); ok {
return len(data)
} else if data, ok := val.Val.([]byte); ok {
return len(data)
} else if data, ok := val.Val.(string); ok {
return len(data)
}
return 0
}
func (val *Value) Raw() interface{} {
return val.Val
}
func (val *Value) Interface() interface{} {
return val.Val
}
func (val *Value) Uint() uint64 {
if Val, ok := val.Val.(uint8); ok {
return uint64(Val)
} else if Val, ok := val.Val.(uint16); ok {
return uint64(Val)
} else if Val, ok := val.Val.(uint32); ok {
return uint64(Val)
} else if Val, ok := val.Val.(uint64); ok {
return Val
} else if Val, ok := val.Val.(int); ok {
return uint64(Val)
} else if Val, ok := val.Val.(uint); ok {
return uint64(Val)
} else if Val, ok := val.Val.([]byte); ok {
return ReadVarint(bytes.NewReader(Val))
}
return 0
}
func (val *Value) Byte() byte {
if Val, ok := val.Val.(byte); ok {
return Val
}
return 0x0
}
func (val *Value) BigInt() *big.Int {
if a, ok := val.Val.([]byte); ok {
b := new(big.Int).SetBytes(a)
return b
} else if a, ok := val.Val.(*big.Int); ok {
return a
} else {
return big.NewInt(int64(val.Uint()))
}
return big.NewInt(0)
}
func (val *Value) Str() string {
if a, ok := val.Val.([]byte); ok {
return string(a)
} else if a, ok := val.Val.(string); ok {
return a
} else if a, ok := val.Val.(byte); ok {
return string(a)
}
return ""
}
func (val *Value) Bytes() []byte {
if a, ok := val.Val.([]byte); ok {
return a
}
return []byte{}
}
func (val *Value) Slice() []interface{} {
if d, ok := val.Val.([]interface{}); ok {
return d
}
return []interface{}{}
}
func (val *Value) SliceFrom(from int) *Value {
slice := val.Slice()
return NewValue(slice[from:])
}
func (val *Value) SliceTo(to int) *Value {
slice := val.Slice()
return NewValue(slice[:to])
}
func (val *Value) SliceFromTo(from, to int) *Value {
slice := val.Slice()
return NewValue(slice[from:to])
}
// TODO More type checking methods
func (val *Value) IsSlice() bool {
return val.Type() == reflect.Slice
}
func (val *Value) IsStr() bool {
return val.Type() == reflect.String
}
// Special list checking function. Something is considered
// a list if it's of type []interface{}. The list is usually
// used in conjunction with rlp decoded streams.
func (val *Value) IsList() bool {
_, ok := val.Val.([]interface{})
return ok
}
func (val *Value) IsEmpty() bool {
return val.Val == nil || ((val.IsSlice() || val.IsStr()) && val.Len() == 0)
}
// Threat the value as a slice
func (val *Value) Get(idx int) *Value {
if d, ok := val.Val.([]interface{}); ok {
// Guard for oob
if len(d) <= idx {
return NewValue(nil)
}
if idx < 0 {
panic("negative idx for Value Get")
}
return NewValue(d[idx])
}
// If this wasn't a slice you probably shouldn't be using this function
return NewValue(nil)
}
func (val *Value) Cmp(o *Value) bool {
return reflect.DeepEqual(val.Val, o.Val)
}
func (val *Value) Encode() []byte {
return Encode(val.Val)
}
func NewValueFromBytes(data []byte) *Value {
if len(data) != 0 {
data, _ := Decode(data, 0)
return NewValue(data)
}
return NewValue(nil)
}
// Value setters
func NewSliceValue(s interface{}) *Value {
list := EmptyValue()
if s != nil {
if slice, ok := s.([]interface{}); ok {
for _, val := range slice {
list.Append(val)
}
} else if slice, ok := s.([]string); ok {
for _, val := range slice {
list.Append(val)
}
}
}
return list
}
func EmptyValue() *Value {
return NewValue([]interface{}{})
}
func (val *Value) AppendList() *Value {
list := EmptyValue()
val.Val = append(val.Slice(), list)
return list
}
func (val *Value) Append(v interface{}) *Value {
val.Val = append(val.Slice(), v)
return val
}
type ValueIterator struct {
value *Value
currentValue *Value
idx int
}
func (val *Value) NewIterator() *ValueIterator {
return &ValueIterator{value: val}
}
func (it *ValueIterator) Next() bool {
if it.idx >= it.value.Len() {
return false
}
it.currentValue = it.value.Get(it.idx)
it.idx++
return true
}
func (it *ValueIterator) Value() *Value {
return it.currentValue
}
func (it *ValueIterator) Idx() int {
return it.idx
}
