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|
import io::{reader, reader_util};
iface to_base64 {
fn to_base64() -> str;
}
impl of to_base64 for ~[u8] {
fn to_base64() -> str {
let chars = str::chars(
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
);
let len = self.len();
let mut s = "";
str::reserve(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(s, chars[(n >> 18u) & 63u]);
str::push_char(s, chars[(n >> 12u) & 63u]);
str::push_char(s, chars[(n >> 6u) & 63u]);
str::push_char(s, chars[n & 63u]);
i += 3u;
}
alt check len % 3u {
0u { }
1u {
let n = (self[i] as uint) << 16u;
str::push_char(s, chars[(n >> 18u) & 63u]);
str::push_char(s, chars[(n >> 12u) & 63u]);
str::push_char(s, '=');
str::push_char(s, '=');
}
2u {
let n = (self[i] as uint) << 16u | (self[i + 1u] as uint) << 8u;
str::push_char(s, chars[(n >> 18u) & 63u]);
str::push_char(s, chars[(n >> 12u) & 63u]);
str::push_char(s, chars[(n >> 6u) & 63u]);
str::push_char(s, '=');
}
}
s
}
}
impl of to_base64 for str {
fn to_base64() -> str {
str::bytes(self).to_base64()
}
}
iface from_base64 {
fn from_base64() -> ~[u8];
}
impl of from_base64 for ~[u8] {
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::reserve(r, (len / 4u) * 3u - padding);
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 == '=' {
alt len - i {
1u {
vec::push(r, ((n >> 16u) & 0xFFu) as u8);
vec::push(r, ((n >> 8u ) & 0xFFu) as u8);
ret copy r;
}
2u {
vec::push(r, ((n >> 10u) & 0xFFu) as u8);
ret copy r;
}
_ {
fail "invalid base64 padding";
}
}
} else {
fail "invalid base64 character";
}
i += 1u;
};
vec::push(r, ((n >> 16u) & 0xFFu) as u8);
vec::push(r, ((n >> 8u ) & 0xFFu) as u8);
vec::push(r, ((n ) & 0xFFu) as u8);
}
r
}
}
impl of from_base64 for str {
fn from_base64() -> ~[u8] {
str::bytes(self).from_base64()
}
}
#[cfg(test)]
mod tests {
#[test]
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]
fn test_from_base64() {
assert "".from_base64() == str::bytes("");
assert "Zg==".from_base64() == str::bytes("f");
assert "Zm8=".from_base64() == str::bytes("fo");
assert "Zm9v".from_base64() == str::bytes("foo");
assert "Zm9vYg==".from_base64() == str::bytes("foob");
assert "Zm9vYmE=".from_base64() == str::bytes("fooba");
assert "Zm9vYmFy".from_base64() == str::bytes("foobar");
}
}
|
