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// Copyright 2012 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.
use core::io::Reader;
use core::iter;
use core::str;
use core::vec;
pub trait ToBase64 {
pure fn to_base64() -> ~str;
}
impl &[u8]: ToBase64 {
pure fn to_base64() -> ~str {
let chars = str::chars(
~"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
);
let mut s = ~"";
unsafe {
let len = self.len();
str::reserve(&mut s, ((len + 3u) / 4u) * 3u);
let mut i = 0u;
while i < len - (len % 3u) {
let n = (self[i] as uint) << 16u |
(self[i + 1u] as uint) << 8u |
(self[i + 2u] as uint);
// This 24-bit number gets separated into four 6-bit numbers.
str::push_char(&mut s, chars[(n >> 18u) & 63u]);
str::push_char(&mut s, chars[(n >> 12u) & 63u]);
str::push_char(&mut s, chars[(n >> 6u) & 63u]);
str::push_char(&mut s, chars[n & 63u]);
i += 3u;
}
// 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 uint) << 16u;
str::push_char(&mut s, chars[(n >> 18u) & 63u]);
str::push_char(&mut s, chars[(n >> 12u) & 63u]);
str::push_char(&mut s, '=');
str::push_char(&mut s, '=');
}
2 => {
let n = (self[i] as uint) << 16u |
(self[i + 1u] as uint) << 8u;
str::push_char(&mut s, chars[(n >> 18u) & 63u]);
str::push_char(&mut s, chars[(n >> 12u) & 63u]);
str::push_char(&mut s, chars[(n >> 6u) & 63u]);
str::push_char(&mut s, '=');
}
_ => fail!(~"Algebra is broken, please alert the math police")
}
}
s
}
}
impl &str: ToBase64 {
pure fn to_base64() -> ~str {
str::to_bytes(self).to_base64()
}
}
pub trait FromBase64 {
pure fn from_base64() -> ~[u8];
}
impl ~[u8]: FromBase64 {
pure fn from_base64() -> ~[u8] {
if self.len() % 4u != 0u { fail!(~"invalid base64 length"); }
let len = self.len();
let mut padding = 0u;
if len != 0u {
if self[len - 1u] == '=' as u8 { padding += 1u; }
if self[len - 2u] == '=' as u8 { padding += 1u; }
}
let mut r = vec::with_capacity((len / 4u) * 3u - padding);
unsafe {
let mut i = 0u;
while i < len {
let mut n = 0u;
for iter::repeat(4u) {
let ch = self[i] as char;
n <<= 6u;
if ch >= 'A' && ch <= 'Z' {
n |= (ch as uint) - 0x41u;
} else if ch >= 'a' && ch <= 'z' {
n |= (ch as uint) - 0x47u;
} else if ch >= '0' && ch <= '9' {
n |= (ch as uint) + 0x04u;
} else if ch == '+' {
n |= 0x3Eu;
} else if ch == '/' {
n |= 0x3Fu;
} else if ch == '=' {
match len - i {
1u => {
r.push(((n >> 16u) & 0xFFu) as u8);
r.push(((n >> 8u ) & 0xFFu) as u8);
return copy r;
}
2u => {
r.push(((n >> 10u) & 0xFFu) as u8);
return copy r;
}
_ => fail!(~"invalid base64 padding")
}
} else {
fail!(~"invalid base64 character");
}
i += 1u;
};
r.push(((n >> 16u) & 0xFFu) as u8);
r.push(((n >> 8u ) & 0xFFu) as u8);
r.push(((n ) & 0xFFu) as u8);
}
}
r
}
}
impl ~str: FromBase64 {
pure fn from_base64() -> ~[u8] {
str::to_bytes(self).from_base64()
}
}
#[cfg(test)]
mod tests {
use core::str;
#[test]
pub fn test_to_base64() {
assert (~"").to_base64() == ~"";
assert (~"f").to_base64() == ~"Zg==";
assert (~"fo").to_base64() == ~"Zm8=";
assert (~"foo").to_base64() == ~"Zm9v";
assert (~"foob").to_base64() == ~"Zm9vYg==";
assert (~"fooba").to_base64() == ~"Zm9vYmE=";
assert (~"foobar").to_base64() == ~"Zm9vYmFy";
}
#[test]
pub fn test_from_base64() {
assert (~"").from_base64() == str::to_bytes(~"");
assert (~"Zg==").from_base64() == str::to_bytes(~"f");
assert (~"Zm8=").from_base64() == str::to_bytes(~"fo");
assert (~"Zm9v").from_base64() == str::to_bytes(~"foo");
assert (~"Zm9vYg==").from_base64() == str::to_bytes(~"foob");
assert (~"Zm9vYmE=").from_base64() == str::to_bytes(~"fooba");
assert (~"Zm9vYmFy").from_base64() == str::to_bytes(~"foobar");
}
}
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