diff options
| -rw-r--r-- | src/libextra/extra.rs | 1 | ||||
| -rw-r--r-- | src/libextra/hex.rs | 238 |
2 files changed, 239 insertions, 0 deletions
diff --git a/src/libextra/extra.rs b/src/libextra/extra.rs index 58929778a59..44781a1fd19 100644 --- a/src/libextra/extra.rs +++ b/src/libextra/extra.rs @@ -102,6 +102,7 @@ pub mod stats; pub mod semver; pub mod fileinput; pub mod flate; +pub mod hex; #[cfg(unicode)] mod unicode; diff --git a/src/libextra/hex.rs b/src/libextra/hex.rs new file mode 100644 index 00000000000..7a1417e72d8 --- /dev/null +++ b/src/libextra/hex.rs @@ -0,0 +1,238 @@ +// Copyright 2013 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +//! Hex binary-to-text encoding +use std::str; +use std::vec; + +/// A trait for converting a value to hexadecimal encoding +pub trait ToHex { + /// Converts the value of `self` to a hex value, returning the owned + /// string. + fn to_hex(&self) -> ~str; +} + +static CHARS: [char, ..16] = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', + 'a', 'b', 'c', 'd', 'e', 'f']; + +impl<'self> ToHex for &'self [u8] { + /** + * Turn a vector of `u8` bytes into a hexadecimal string. + * + * # Example + * + * ~~~ {.rust} + * extern mod extra; + * use extra::hex::ToHex; + * + * fn main () { + * let str = [52,32].to_hex(); + * printfln!("%s", str); + * } + * ~~~ + */ + fn to_hex(&self) -> ~str { + let mut s = str::with_capacity(self.len() * 2); + for &byte in self.iter() { + s.push_char(CHARS[byte >> 4]); + s.push_char(CHARS[byte & 0xf]); + } + + s + } +} + +impl<'self> ToHex for &'self str { + /** + * Convert any string (literal, `@`, `&`, or `~`) to hexadecimal encoding. + * + * + * # Example + * + * ~~~ {.rust} + * extern mod extra; + * use extra::ToHex; + * + * fn main () { + * let str = "Hello, World".to_hex(); + * printfln!("%s", str); + * } + * ~~~ + * + */ + fn to_hex(&self) -> ~str { + self.as_bytes().to_hex() + } +} + +/// A trait for converting hexadecimal encoded values +pub trait FromHex { + /// Converts the value of `self`, interpreted as base64 encoded data, into + /// an owned vector of bytes, returning the vector. + fn from_hex(&self) -> Result<~[u8], ~str>; +} + +impl<'self> FromHex for &'self [u8] { + /** + * Convert hexadecimal `u8` vector into u8 byte values. + * Every 2 encoded characters is converted into 1 octet. + * + * # Example + * + * ~~~ {.rust} + * extern mod extra; + * use extra::hex::{ToHex, FromHex}; + * + * fn main () { + * let str = [52,32].to_hex(); + * printfln!("%s", str); + * let bytes = str.from_hex().get(); + * printfln!("%?", bytes); + * } + * ~~~ + */ + fn from_hex(&self) -> Result<~[u8], ~str> { + // This may be an overestimate if there is any whitespace + let mut b = vec::with_capacity(self.len() / 2); + let mut modulus = 0; + let mut buf = 0u8; + + for &byte in self.iter() { + buf <<= 4; + + match byte as char { + 'A'..'F' => buf |= byte - ('A' as u8) + 10, + 'a'..'f' => buf |= byte - ('a' as u8) + 10, + '0'..'9' => buf |= byte - ('0' as u8), + ' '|'\r'|'\n' => { + buf >>= 4; + loop + } + _ => return Err(~"Invalid hex char") + } + + modulus += 1; + if modulus == 2 { + modulus = 0; + b.push(buf); + } + } + + match modulus { + 0 => Ok(b), + _ => Err(~"Invalid input length") + } + } +} + +impl<'self> FromHex for &'self str { + /** + * Convert any hexadecimal encoded string (literal, `@`, `&`, or `~`) + * to the byte values it encodes. + * + * You can use the `from_bytes` function in `std::str` + * to turn a `[u8]` into a string with characters corresponding to those + * values. + * + * # Example + * + * This converts a string literal to hexadecimal and back. + * + * ~~~ {.rust} + * extern mod extra; + * use extra::hex::{FromHex, ToHex}; + * use std::str; + * + * fn main () { + * let hello_str = "Hello, World".to_hex(); + * printfln!("%s", hello_str); + * let bytes = hello_str.from_hex().get(); + * printfln!("%?", bytes); + * let result_str = str::from_bytes(bytes); + * printfln!("%s", result_str); + * } + * ~~~ + */ + fn from_hex(&self) -> Result<~[u8], ~str> { + self.as_bytes().from_hex() + } +} + +#[cfg(test)] +mod tests { + use test::BenchHarness; + use hex::*; + + #[test] + pub fn test_to_hex() { + assert_eq!("foobar".to_hex(), ~"666f6f626172"); + } + + #[test] + pub fn test_from_hex_okay() { + assert_eq!("666f6f626172".from_hex().get(), + "foobar".as_bytes().to_owned()); + assert_eq!("666F6F626172".from_hex().get(), + "foobar".as_bytes().to_owned()); + } + + #[test] + pub fn test_from_hex_odd_len() { + assert!("666".from_hex().is_err()); + assert!("66 6".from_hex().is_err()); + } + + #[test] + pub fn test_from_hex_invalid_char() { + assert!("66y6".from_hex().is_err()); + } + + #[test] + pub fn test_from_hex_ignores_whitespace() { + assert_eq!("666f 6f6\r\n26172 ".from_hex().get(), + "foobar".as_bytes().to_owned()); + } + + #[test] + pub fn test_to_hex_all_bytes() { + for i in range(0, 256) { + assert_eq!([i as u8].to_hex(), fmt!("%02x", i as uint)); + } + } + + #[test] + pub fn test_from_hex_all_bytes() { + for i in range(0, 256) { + assert_eq!(fmt!("%02x", i as uint).from_hex().get(), ~[i as u8]); + assert_eq!(fmt!("%02X", i as uint).from_hex().get(), ~[i as u8]); + } + } + + #[bench] + pub fn bench_to_hex(bh: & mut BenchHarness) { + 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 \ + 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"; + do bh.iter { + s.to_hex(); + } + bh.bytes = s.len() as u64; + } + + #[bench] + pub fn bench_from_hex(bh: & mut BenchHarness) { + 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 \ + 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"; + let b = s.to_hex(); + do bh.iter { + b.from_hex(); + } + bh.bytes = b.len() as u64; + } +} |