1 // Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Hex binary-to-text encoding
13 pub use self::FromHexError::*;
18 /// A trait for converting a value to hexadecimal encoding
20 /// Converts the value of `self` to a hex value, returning the owned
22 fn to_hex(&self) -> String;
25 const CHARS: &'static [u8] = b"0123456789abcdef";
28 /// Turn a vector of `u8` bytes into a hexadecimal string.
33 /// # #![feature(rustc_private)]
34 /// extern crate serialize;
35 /// use serialize::hex::ToHex;
38 /// let str = [52,32].to_hex();
39 /// println!("{}", str);
42 fn to_hex(&self) -> String {
43 let mut v = Vec::with_capacity(self.len() * 2);
45 v.push(CHARS[(byte >> 4) as usize]);
46 v.push(CHARS[(byte & 0xf) as usize]);
50 String::from_utf8_unchecked(v)
55 /// A trait for converting hexadecimal encoded values
57 /// Converts the value of `self`, interpreted as hexadecimal encoded data,
58 /// into an owned vector of bytes, returning the vector.
59 fn from_hex(&self) -> Result<Vec<u8>, FromHexError>;
62 /// Errors that can occur when decoding a hex encoded string
63 #[derive(Copy, Clone, Debug)]
64 pub enum FromHexError {
65 /// The input contained a character not part of the hex format
66 InvalidHexCharacter(char, usize),
67 /// The input had an invalid length
71 impl fmt::Display for FromHexError {
72 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
74 InvalidHexCharacter(ch, idx) =>
75 write!(f, "Invalid character '{}' at position {}", ch, idx),
76 InvalidHexLength => write!(f, "Invalid input length"),
81 impl error::Error for FromHexError {
82 fn description(&self) -> &str {
84 InvalidHexCharacter(_, _) => "invalid character",
85 InvalidHexLength => "invalid length",
91 impl FromHex for str {
92 /// Convert any hexadecimal encoded string (literal, `@`, `&`, or `~`)
93 /// to the byte values it encodes.
95 /// You can use the `String::from_utf8` function to turn a
96 /// `Vec<u8>` into a string with characters corresponding to those values.
100 /// This converts a string literal to hexadecimal and back.
103 /// # #![feature(rustc_private)]
104 /// extern crate serialize;
105 /// use serialize::hex::{FromHex, ToHex};
108 /// let hello_str = "Hello, World".as_bytes().to_hex();
109 /// println!("{}", hello_str);
110 /// let bytes = hello_str.from_hex().unwrap();
111 /// println!("{:?}", bytes);
112 /// let result_str = String::from_utf8(bytes).unwrap();
113 /// println!("{}", result_str);
116 fn from_hex(&self) -> Result<Vec<u8>, FromHexError> {
117 // This may be an overestimate if there is any whitespace
118 let mut b = Vec::with_capacity(self.len() / 2);
122 for (idx, byte) in self.bytes().enumerate() {
126 b'A'...b'F' => buf |= byte - b'A' + 10,
127 b'a'...b'f' => buf |= byte - b'a' + 10,
128 b'0'...b'9' => buf |= byte - b'0',
129 b' '|b'\r'|b'\n'|b'\t' => {
133 _ => return Err(InvalidHexCharacter(self.char_at(idx), idx)),
144 0 => Ok(b.into_iter().collect()),
145 _ => Err(InvalidHexLength),
153 use self::test::Bencher;
154 use hex::{FromHex, ToHex};
157 pub fn test_to_hex() {
158 assert_eq!("foobar".as_bytes().to_hex(), "666f6f626172");
162 pub fn test_from_hex_okay() {
163 assert_eq!("666f6f626172".from_hex().unwrap(),
165 assert_eq!("666F6F626172".from_hex().unwrap(),
170 pub fn test_from_hex_odd_len() {
171 assert!("666".from_hex().is_err());
172 assert!("66 6".from_hex().is_err());
176 pub fn test_from_hex_invalid_char() {
177 assert!("66y6".from_hex().is_err());
181 pub fn test_from_hex_ignores_whitespace() {
182 assert_eq!("666f 6f6\r\n26172 ".from_hex().unwrap(),
187 pub fn test_to_hex_all_bytes() {
189 assert_eq!([i as u8].to_hex(), format!("{:02x}", i as usize));
194 pub fn test_from_hex_all_bytes() {
196 let ii: &[u8] = &[i as u8];
197 assert_eq!(format!("{:02x}", i as usize).from_hex()
200 assert_eq!(format!("{:02X}", i as usize).from_hex()
207 pub fn bench_to_hex(b: &mut Bencher) {
208 let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
209 ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
211 s.as_bytes().to_hex();
213 b.bytes = s.len() as u64;
217 pub fn bench_from_hex(b: &mut Bencher) {
218 let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
219 ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
220 let sb = s.as_bytes().to_hex();
222 sb.from_hex().unwrap();
224 b.bytes = sb.len() as u64;