neo-go/pkg/util/size.go

90 lines
2.2 KiB
Go

package util
import (
"fmt"
"reflect"
"github.com/CityOfZion/neo-go/pkg/io"
)
var (
bit8 byte
ui8 uint8
ui16 uint16
ui32 uint32
ui64 uint64
i8 int8
i16 int16
i32 int32
i64 int64
)
// GetVarIntSize returns the size in number of bytes of a variable integer
// (reference: GetVarSize(int value), https://github.com/neo-project/neo/blob/master/neo/IO/Helper.cs)
func GetVarIntSize(value int) int {
var size uintptr
if value < 0xFD {
size = 1 // unit8
} else if value <= 0xFFFF {
size = 3 // byte + uint16
} else {
size = 5 // byte + uint32
}
return int(size)
}
// GetVarStringSize returns the size of a variable string
// (reference: GetVarSize(this string value), https://github.com/neo-project/neo/blob/master/neo/IO/Helper.cs)
func GetVarStringSize(value string) int {
valueSize := len([]byte(value))
return GetVarIntSize(valueSize) + valueSize
}
// GetVarSize return the size om bytes of a variable. This implementation is not exactly like the C#
// (reference: GetVarSize<T>(this T[] value), https://github.com/neo-project/neo/blob/master/neo/IO/Helper.cs#L53) as in the C# variable
// like Uint160, Uint256 are not supported.
func GetVarSize(value interface{}) int {
v := reflect.ValueOf(value)
switch v.Kind() {
case reflect.String:
return GetVarStringSize(v.String())
case reflect.Int,
reflect.Int8,
reflect.Int16,
reflect.Int32,
reflect.Int64:
return GetVarIntSize(int(v.Int()))
case reflect.Uint,
reflect.Uint8,
reflect.Uint16,
reflect.Uint32,
reflect.Uint64:
return GetVarIntSize(int(v.Uint()))
case reflect.Slice, reflect.Array:
valueLength := v.Len()
valueSize := 0
if valueLength != 0 {
switch reflect.ValueOf(value).Index(0).Interface().(type) {
case io.Serializable:
for i := 0; i < valueLength; i++ {
elem := v.Index(i).Interface().(io.Serializable)
valueSize += elem.Size()
}
case uint8, int8:
valueSize = valueLength
case uint16, int16:
valueSize = valueLength * 2
case uint32, int32:
valueSize = valueLength * 4
case uint64, int64:
valueSize = valueLength * 8
}
}
return GetVarIntSize(valueLength) + valueSize
default:
panic(fmt.Sprintf("unable to calculate GetVarSize, %s", reflect.TypeOf(value)))
}
}