rust/src/libextra/base64.rs
bors a4ec8af4c5 auto merge of #9810 : huonw/rust/rand3, r=alexcrichton
- Adds the `Sample` and `IndependentSample` traits for generating numbers where there are parameters (e.g. a list of elements to draw from, or the mean/variance of a normal distribution). The former takes `&mut self` and the latter takes `&self` (this is the only difference).
- Adds proper `Normal` and `Exp`-onential distributions
- Adds `Range` which generates `[lo, hi)` generically & properly (via a new trait) replacing the incorrect behaviour of `Rng.gen_integer_range` (this has become `Rng.gen_range` for convenience, it's far more efficient to use `Range` itself)
- Move the `Weighted` struct from `std::rand` to `std::rand::distributions` & improve it
- optimisations and docs
2013-10-23 08:31:21 -07:00

349 lines
11 KiB
Rust

// Copyright 2012-2013 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.
//! Base64 binary-to-text encoding
use std::str;
/// Available encoding character sets
pub enum CharacterSet {
/// The standard character set (uses `+` and `/`)
Standard,
/// The URL safe character set (uses `-` and `_`)
UrlSafe
}
/// Contains configuration parameters for `to_base64`.
pub struct Config {
/// Character set to use
priv char_set: CharacterSet,
/// True to pad output with `=` characters
priv pad: bool,
/// `Some(len)` to wrap lines at `len`, `None` to disable line wrapping
priv line_length: Option<uint>
}
/// Configuration for RFC 4648 standard base64 encoding
pub static STANDARD: Config =
Config {char_set: Standard, pad: true, line_length: None};
/// Configuration for RFC 4648 base64url encoding
pub static URL_SAFE: Config =
Config {char_set: UrlSafe, pad: false, line_length: None};
/// Configuration for RFC 2045 MIME base64 encoding
pub static MIME: Config =
Config {char_set: Standard, pad: true, line_length: Some(76)};
static STANDARD_CHARS: &'static[u8] = bytes!("ABCDEFGHIJKLMNOPQRSTUVWXYZ",
"abcdefghijklmnopqrstuvwxyz",
"0123456789+/");
static URLSAFE_CHARS: &'static[u8] = bytes!("ABCDEFGHIJKLMNOPQRSTUVWXYZ",
"abcdefghijklmnopqrstuvwxyz",
"0123456789-_");
/// A trait for converting a value to base64 encoding.
pub trait ToBase64 {
/// Converts the value of `self` to a base64 value following the specified
/// format configuration, returning the owned string.
fn to_base64(&self, config: Config) -> ~str;
}
impl<'self> ToBase64 for &'self [u8] {
/**
* Turn a vector of `u8` bytes into a base64 string.
*
* # Example
*
* ```rust
* extern mod extra;
* use extra::base64::{ToBase64, STANDARD};
*
* fn main () {
* let str = [52,32].to_base64(STANDARD);
* println!("base 64 output: {}", str);
* }
* ```
*/
fn to_base64(&self, config: Config) -> ~str {
let bytes = match config.char_set {
Standard => STANDARD_CHARS,
UrlSafe => URLSAFE_CHARS
};
let mut v: ~[u8] = ~[];
let mut i = 0;
let mut cur_length = 0;
let len = self.len();
while i < len - (len % 3) {
match config.line_length {
Some(line_length) =>
if cur_length >= line_length {
v.push('\r' as u8);
v.push('\n' as u8);
cur_length = 0;
},
None => ()
}
let n = (self[i] as u32) << 16 |
(self[i + 1] as u32) << 8 |
(self[i + 2] as u32);
// This 24-bit number gets separated into four 6-bit numbers.
v.push(bytes[(n >> 18) & 63]);
v.push(bytes[(n >> 12) & 63]);
v.push(bytes[(n >> 6 ) & 63]);
v.push(bytes[n & 63]);
cur_length += 4;
i += 3;
}
if len % 3 != 0 {
match config.line_length {
Some(line_length) =>
if cur_length >= line_length {
v.push('\r' as u8);
v.push('\n' as u8);
},
None => ()
}
}
// Heh, would be cool if we knew this was exhaustive
// (the dream of bounded integer types)
match len % 3 {
0 => (),
1 => {
let n = (self[i] as u32) << 16;
v.push(bytes[(n >> 18) & 63]);
v.push(bytes[(n >> 12) & 63]);
if config.pad {
v.push('=' as u8);
v.push('=' as u8);
}
}
2 => {
let n = (self[i] as u32) << 16 |
(self[i + 1u] as u32) << 8;
v.push(bytes[(n >> 18) & 63]);
v.push(bytes[(n >> 12) & 63]);
v.push(bytes[(n >> 6 ) & 63]);
if config.pad {
v.push('=' as u8);
}
}
_ => fail!("Algebra is broken, please alert the math police")
}
unsafe {
str::raw::from_utf8_owned(v)
}
}
}
/// A trait for converting from base64 encoded values.
pub trait FromBase64 {
/// Converts the value of `self`, interpreted as base64 encoded data, into
/// an owned vector of bytes, returning the vector.
fn from_base64(&self) -> Result<~[u8], ~str>;
}
impl<'self> FromBase64 for &'self str {
/**
* Convert any base64 encoded string (literal, `@`, `&`, or `~`)
* to the byte values it encodes.
*
* You can use the `from_utf8` function in `std::str`
* to turn a `[u8]` into a string with characters corresponding to those
* values.
*
* # Example
*
* This converts a string literal to base64 and back.
*
* ```rust
* extern mod extra;
* use extra::base64::{ToBase64, FromBase64, STANDARD};
* use std::str;
*
* fn main () {
* let hello_str = bytes!("Hello, World").to_base64(STANDARD);
* println!("base64 output: {}", hello_str);
* let res = hello_str.from_base64();
* if res.is_ok() {
* let optBytes = str::from_utf8_opt(res.unwrap());
* if optBytes.is_some() {
* println!("decoded from base64: {}", optBytes.unwrap());
* }
* }
* }
* ```
*/
fn from_base64(&self) -> Result<~[u8], ~str> {
let mut r = ~[];
let mut buf: u32 = 0;
let mut modulus = 0;
let mut it = self.byte_iter().enumerate();
for (idx, byte) in it {
let val = byte as u32;
match byte as char {
'A'..'Z' => buf |= val - 0x41,
'a'..'z' => buf |= val - 0x47,
'0'..'9' => buf |= val + 0x04,
'+'|'-' => buf |= 0x3E,
'/'|'_' => buf |= 0x3F,
'\r'|'\n' => continue,
'=' => break,
_ => return Err(format!("Invalid character '{}' at position {}",
self.char_at(idx), idx))
}
buf <<= 6;
modulus += 1;
if modulus == 4 {
modulus = 0;
r.push((buf >> 22) as u8);
r.push((buf >> 14) as u8);
r.push((buf >> 6 ) as u8);
}
}
for (idx, byte) in it {
if (byte as char) != '=' {
return Err(format!("Invalid character '{}' at position {}",
self.char_at(idx), idx));
}
}
match modulus {
2 => {
r.push((buf >> 10) as u8);
}
3 => {
r.push((buf >> 16) as u8);
r.push((buf >> 8 ) as u8);
}
0 => (),
_ => return Err(~"Invalid Base64 length")
}
Ok(r)
}
}
#[cfg(test)]
mod test {
use test::BenchHarness;
use base64::*;
#[test]
fn test_to_base64_basic() {
assert_eq!("".as_bytes().to_base64(STANDARD), ~"");
assert_eq!("f".as_bytes().to_base64(STANDARD), ~"Zg==");
assert_eq!("fo".as_bytes().to_base64(STANDARD), ~"Zm8=");
assert_eq!("foo".as_bytes().to_base64(STANDARD), ~"Zm9v");
assert_eq!("foob".as_bytes().to_base64(STANDARD), ~"Zm9vYg==");
assert_eq!("fooba".as_bytes().to_base64(STANDARD), ~"Zm9vYmE=");
assert_eq!("foobar".as_bytes().to_base64(STANDARD), ~"Zm9vYmFy");
}
#[test]
fn test_to_base64_line_break() {
assert!(![0u8, 1000].to_base64(Config {line_length: None, ..STANDARD})
.contains("\r\n"));
assert_eq!("foobar".as_bytes().to_base64(Config {line_length: Some(4),
..STANDARD}),
~"Zm9v\r\nYmFy");
}
#[test]
fn test_to_base64_padding() {
assert_eq!("f".as_bytes().to_base64(Config {pad: false, ..STANDARD}), ~"Zg");
assert_eq!("fo".as_bytes().to_base64(Config {pad: false, ..STANDARD}), ~"Zm8");
}
#[test]
fn test_to_base64_url_safe() {
assert_eq!([251, 255].to_base64(URL_SAFE), ~"-_8");
assert_eq!([251, 255].to_base64(STANDARD), ~"+/8=");
}
#[test]
fn test_from_base64_basic() {
assert_eq!("".from_base64().unwrap(), "".as_bytes().to_owned());
assert_eq!("Zg==".from_base64().unwrap(), "f".as_bytes().to_owned());
assert_eq!("Zm8=".from_base64().unwrap(), "fo".as_bytes().to_owned());
assert_eq!("Zm9v".from_base64().unwrap(), "foo".as_bytes().to_owned());
assert_eq!("Zm9vYg==".from_base64().unwrap(), "foob".as_bytes().to_owned());
assert_eq!("Zm9vYmE=".from_base64().unwrap(), "fooba".as_bytes().to_owned());
assert_eq!("Zm9vYmFy".from_base64().unwrap(), "foobar".as_bytes().to_owned());
}
#[test]
fn test_from_base64_newlines() {
assert_eq!("Zm9v\r\nYmFy".from_base64().unwrap(),
"foobar".as_bytes().to_owned());
}
#[test]
fn test_from_base64_urlsafe() {
assert_eq!("-_8".from_base64().unwrap(), "+/8=".from_base64().unwrap());
}
#[test]
fn test_from_base64_invalid_char() {
assert!("Zm$=".from_base64().is_err())
assert!("Zg==$".from_base64().is_err());
}
#[test]
fn test_from_base64_invalid_padding() {
assert!("Z===".from_base64().is_err());
}
#[test]
fn test_base64_random() {
use std::rand::{task_rng, random, Rng};
use std::vec;
do 1000.times {
let times = task_rng().gen_range(1u, 100);
let v = vec::from_fn(times, |_| random::<u8>());
assert_eq!(v.to_base64(STANDARD).from_base64().unwrap(), v);
}
}
#[bench]
pub fn bench_to_base64(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.as_bytes().to_base64(STANDARD);
}
bh.bytes = s.len() as u64;
}
#[bench]
pub fn bench_from_base64(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.as_bytes().to_base64(STANDARD);
do bh.iter {
b.from_base64();
}
bh.bytes = b.len() as u64;
}
}