// 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 common
import (
"fmt"
"math/big"
"math/rand"
"reflect"
"github.com/ethereum/go-ethereum/common/hexutil"
)
const (
HashLength = 32
AddressLength = 20
)
type (
// Hash represents the 32 byte Keccak256 hash of arbitrary data.
Hash [HashLength]byte
// Address represents the 20 byte address of an Ethereum account.
Address [AddressLength]byte
)
func BytesToHash(b []byte) Hash {
var h Hash
h.SetBytes(b)
return h
}
func StringToHash(s string) Hash { return BytesToHash([]byte(s)) }
func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
func HexToHash(s string) Hash { return BytesToHash(FromHex(s)) }
// Don't use the default 'String' method in case we want to overwrite
// Get the string representation of the underlying hash
func (h Hash) Str() string { return string(h[:]) }
func (h Hash) Bytes() []byte { return h[:] }
func (h Hash) Big() *big.Int { return Bytes2Big(h[:]) }
func (h Hash) Hex() string { return hexutil.Encode(h[:]) }
// UnmarshalJSON parses a hash in its hex from to a hash.
func (h *Hash) UnmarshalJSON(input []byte) error {
return hexutil.UnmarshalJSON("Hash", input, h[:])
}
// Serialize given hash to JSON
func (h Hash) MarshalJSON() ([]byte, error) {
return hexutil.Bytes(h[:]).MarshalJSON()
}
// Sets the hash to the value of b. If b is larger than len(h) it will panic
func (h *Hash) SetBytes(b []byte) {
if len(b) > len(h) {
b = b[len(b)-HashLength:]
}
copy(h[HashLength-len(b):], b)
}
// Set string `s` to h. If s is larger than len(h) it will panic
func (h *Hash) SetString(s string) { h.SetBytes([]byte(s)) }
// Sets h to other
func (h *Hash) Set(other Hash) {
for i, v := range other {
h[i] = v
}
}
// Generate implements testing/quick.Generator.
func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
m := rand.Intn(len(h))
for i := len(h) - 1; i > m; i-- {
h[i] = byte(rand.Uint32())
}
return reflect.ValueOf(h)
}
func EmptyHash(h Hash) bool {
return h == Hash{}
}
/////////// Address
func BytesToAddress(b []byte) Address {
var a Address
a.SetBytes(b)
return a
}
func StringToAddress(s string) Address { return BytesToAddress([]byte(s)) }
func BigToAddress(b *big.Int) Address { return BytesToAddress(b.Bytes()) }
func HexToAddress(s string) Address { return BytesToAddress(FromHex(s)) }
// IsHexAddress verifies whether a string can represent a valid hex-encoded
// Ethereum address or not.
func IsHexAddress(s string) bool {
if len(s) == 2+2*AddressLength && IsHex(s) {
return true
}
if len(s) == 2*AddressLength && IsHex("0x"+s) {
return true
}
return false
}
// Get the string representation of the underlying address
func (a Address) Str() string { return string(a[:]) }
func (a Address) Bytes() []byte { return a[:] }
func (a Address) Big() *big.Int { return Bytes2Big(a[:]) }
func (a Address) Hash() Hash { return BytesToHash(a[:]) }
func (a Address) Hex() string { return hexutil.Encode(a[:]) }
// Sets the address to the value of b. If b is larger than len(a) it will panic
func (a *Address) SetBytes(b []byte) {
if len(b) > len(a) {
b = b[len(b)-AddressLength:]
}
copy(a[AddressLength-len(b):], b)
}
// Set string `s` to a. If s is larger than len(a) it will panic
func (a *Address) SetString(s string) { a.SetBytes([]byte(s)) }
// Sets a to other
func (a *Address) Set(other Address) {
for i, v := range other {
a[i] = v
}
}
// Serialize given address to JSON
func (a Address) MarshalJSON() ([]byte, error) {
return hexutil.Bytes(a[:]).MarshalJSON()
}
// Parse address from raw json data
func (a *Address) UnmarshalJSON(input []byte) error {
return hexutil.UnmarshalJSON("Address", input, a[:])
}
// PP Pretty Prints a byte slice in the following format:
// hex(value[:4])...(hex[len(value)-4:])
func PP(value []byte) string {
if len(value) <= 8 {
return Bytes2Hex(value)
}
return fmt.Sprintf("%x...%x", value[:4], value[len(value)-4])
}
