github.com/fxsjy/go-ethereum@v1.8.4-0.20180410143526-2e247705cd27/common/types.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package common
    18  
    19  import (
    20  	"encoding/hex"
    21  	"fmt"
    22  	"math/big"
    23  	"math/rand"
    24  	"reflect"
    25  
    26  	"github.com/ethereum/go-ethereum/common/hexutil"
    27  	"github.com/ethereum/go-ethereum/crypto/sha3"
    28  )
    29  
    30  const (
    31  	HashLength    = 32
    32  	AddressLength = 20
    33  )
    34  
    35  var (
    36  	hashT    = reflect.TypeOf(Hash{})
    37  	addressT = reflect.TypeOf(Address{})
    38  )
    39  
    40  // Hash represents the 32 byte Keccak256 hash of arbitrary data.
    41  type Hash [HashLength]byte
    42  
    43  func BytesToHash(b []byte) Hash {
    44  	var h Hash
    45  	h.SetBytes(b)
    46  	return h
    47  }
    48  func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
    49  func HexToHash(s string) Hash   { return BytesToHash(FromHex(s)) }
    50  
    51  // Get the string representation of the underlying hash
    52  func (h Hash) Str() string   { return string(h[:]) }
    53  func (h Hash) Bytes() []byte { return h[:] }
    54  func (h Hash) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }
    55  func (h Hash) Hex() string   { return hexutil.Encode(h[:]) }
    56  
    57  // TerminalString implements log.TerminalStringer, formatting a string for console
    58  // output during logging.
    59  func (h Hash) TerminalString() string {
    60  	return fmt.Sprintf("%x…%x", h[:3], h[29:])
    61  }
    62  
    63  // String implements the stringer interface and is used also by the logger when
    64  // doing full logging into a file.
    65  func (h Hash) String() string {
    66  	return h.Hex()
    67  }
    68  
    69  // Format implements fmt.Formatter, forcing the byte slice to be formatted as is,
    70  // without going through the stringer interface used for logging.
    71  func (h Hash) Format(s fmt.State, c rune) {
    72  	fmt.Fprintf(s, "%"+string(c), h[:])
    73  }
    74  
    75  // UnmarshalText parses a hash in hex syntax.
    76  func (h *Hash) UnmarshalText(input []byte) error {
    77  	return hexutil.UnmarshalFixedText("Hash", input, h[:])
    78  }
    79  
    80  // UnmarshalJSON parses a hash in hex syntax.
    81  func (h *Hash) UnmarshalJSON(input []byte) error {
    82  	return hexutil.UnmarshalFixedJSON(hashT, input, h[:])
    83  }
    84  
    85  // MarshalText returns the hex representation of h.
    86  func (h Hash) MarshalText() ([]byte, error) {
    87  	return hexutil.Bytes(h[:]).MarshalText()
    88  }
    89  
    90  // Sets the hash to the value of b. If b is larger than len(h), 'b' will be cropped (from the left).
    91  func (h *Hash) SetBytes(b []byte) {
    92  	if len(b) > len(h) {
    93  		b = b[len(b)-HashLength:]
    94  	}
    95  
    96  	copy(h[HashLength-len(b):], b)
    97  }
    98  
    99  // Set string `s` to h. If s is larger than len(h) s will be cropped (from left) to fit.
   100  func (h *Hash) SetString(s string) { h.SetBytes([]byte(s)) }
   101  
   102  // Sets h to other
   103  func (h *Hash) Set(other Hash) {
   104  	for i, v := range other {
   105  		h[i] = v
   106  	}
   107  }
   108  
   109  // Generate implements testing/quick.Generator.
   110  func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
   111  	m := rand.Intn(len(h))
   112  	for i := len(h) - 1; i > m; i-- {
   113  		h[i] = byte(rand.Uint32())
   114  	}
   115  	return reflect.ValueOf(h)
   116  }
   117  
   118  func EmptyHash(h Hash) bool {
   119  	return h == Hash{}
   120  }
   121  
   122  // UnprefixedHash allows marshaling a Hash without 0x prefix.
   123  type UnprefixedHash Hash
   124  
   125  // UnmarshalText decodes the hash from hex. The 0x prefix is optional.
   126  func (h *UnprefixedHash) UnmarshalText(input []byte) error {
   127  	return hexutil.UnmarshalFixedUnprefixedText("UnprefixedHash", input, h[:])
   128  }
   129  
   130  // MarshalText encodes the hash as hex.
   131  func (h UnprefixedHash) MarshalText() ([]byte, error) {
   132  	return []byte(hex.EncodeToString(h[:])), nil
   133  }
   134  
   135  /////////// Address
   136  
   137  // Address represents the 20 byte address of an Ethereum account.
   138  type Address [AddressLength]byte
   139  
   140  func BytesToAddress(b []byte) Address {
   141  	var a Address
   142  	a.SetBytes(b)
   143  	return a
   144  }
   145  func BigToAddress(b *big.Int) Address { return BytesToAddress(b.Bytes()) }
   146  func HexToAddress(s string) Address   { return BytesToAddress(FromHex(s)) }
   147  
   148  // IsHexAddress verifies whether a string can represent a valid hex-encoded
   149  // Ethereum address or not.
   150  func IsHexAddress(s string) bool {
   151  	if hasHexPrefix(s) {
   152  		s = s[2:]
   153  	}
   154  	return len(s) == 2*AddressLength && isHex(s)
   155  }
   156  
   157  // Get the string representation of the underlying address
   158  func (a Address) Str() string   { return string(a[:]) }
   159  func (a Address) Bytes() []byte { return a[:] }
   160  func (a Address) Big() *big.Int { return new(big.Int).SetBytes(a[:]) }
   161  func (a Address) Hash() Hash    { return BytesToHash(a[:]) }
   162  
   163  // Hex returns an EIP55-compliant hex string representation of the address.
   164  func (a Address) Hex() string {
   165  	unchecksummed := hex.EncodeToString(a[:])
   166  	sha := sha3.NewKeccak256()
   167  	sha.Write([]byte(unchecksummed))
   168  	hash := sha.Sum(nil)
   169  
   170  	result := []byte(unchecksummed)
   171  	for i := 0; i < len(result); i++ {
   172  		hashByte := hash[i/2]
   173  		if i%2 == 0 {
   174  			hashByte = hashByte >> 4
   175  		} else {
   176  			hashByte &= 0xf
   177  		}
   178  		if result[i] > '9' && hashByte > 7 {
   179  			result[i] -= 32
   180  		}
   181  	}
   182  	return "0x" + string(result)
   183  }
   184  
   185  // String implements the stringer interface and is used also by the logger.
   186  func (a Address) String() string {
   187  	return a.Hex()
   188  }
   189  
   190  // Format implements fmt.Formatter, forcing the byte slice to be formatted as is,
   191  // without going through the stringer interface used for logging.
   192  func (a Address) Format(s fmt.State, c rune) {
   193  	fmt.Fprintf(s, "%"+string(c), a[:])
   194  }
   195  
   196  // Sets the address to the value of b. If b is larger than len(a) it will panic
   197  func (a *Address) SetBytes(b []byte) {
   198  	if len(b) > len(a) {
   199  		b = b[len(b)-AddressLength:]
   200  	}
   201  	copy(a[AddressLength-len(b):], b)
   202  }
   203  
   204  // Set string `s` to a. If s is larger than len(a) it will panic
   205  func (a *Address) SetString(s string) { a.SetBytes([]byte(s)) }
   206  
   207  // Sets a to other
   208  func (a *Address) Set(other Address) {
   209  	for i, v := range other {
   210  		a[i] = v
   211  	}
   212  }
   213  
   214  // MarshalText returns the hex representation of a.
   215  func (a Address) MarshalText() ([]byte, error) {
   216  	return hexutil.Bytes(a[:]).MarshalText()
   217  }
   218  
   219  // UnmarshalText parses a hash in hex syntax.
   220  func (a *Address) UnmarshalText(input []byte) error {
   221  	return hexutil.UnmarshalFixedText("Address", input, a[:])
   222  }
   223  
   224  // UnmarshalJSON parses a hash in hex syntax.
   225  func (a *Address) UnmarshalJSON(input []byte) error {
   226  	return hexutil.UnmarshalFixedJSON(addressT, input, a[:])
   227  }
   228  
   229  // UnprefixedHash allows marshaling an Address without 0x prefix.
   230  type UnprefixedAddress Address
   231  
   232  // UnmarshalText decodes the address from hex. The 0x prefix is optional.
   233  func (a *UnprefixedAddress) UnmarshalText(input []byte) error {
   234  	return hexutil.UnmarshalFixedUnprefixedText("UnprefixedAddress", input, a[:])
   235  }
   236  
   237  // MarshalText encodes the address as hex.
   238  func (a UnprefixedAddress) MarshalText() ([]byte, error) {
   239  	return []byte(hex.EncodeToString(a[:])), nil
   240  }