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use alloc::{
string::String,
};
use super::{
PAD_CHAR,
Kind,
};
fn add_char(s: &mut String, chr: &char, max_line_len: &usize, line_separators: &Option<&[char]>, line_column: &mut usize) {
s.push(*chr);
if *max_line_len == 0 {
return;
}
if let Some(line_separators) = line_separators {
*line_column = (*line_column).saturating_add(1);
if *line_column >= *max_line_len {
for chr in line_separators.iter() {
s.push(*chr);
}
*line_column = 0;
}
}
}
pub fn encode<B>(bytes: B, kind: Kind) -> String where B: AsRef<[u8]> {
let bytes = bytes.as_ref();
let mut result = String::with_capacity(kind.estimate_encoding_capacity(bytes));
let max_line_len = kind.max_line_len().unwrap_or(0);
let line_separators = kind.line_separators();
let mut line_column = 0;
let must_use_pad = kind.must_use_pad();
let last_chars = kind.last_chars();
let len = bytes.len();
let mut index = 0;
loop {
let byte = match index < len {
true => bytes[index],
false => break,
};
add_char(&mut result, Kind::get_char((byte >> 2) as usize, last_chars), &max_line_len, &line_separators, &mut line_column);
index += 1;
let bits = (byte << 6) >> 2;
match index < len {
true => {
let byte = bytes[index];
index += 1;
add_char(
&mut result, Kind::get_char((bits | (byte >> 4)) as usize, last_chars), &max_line_len, &line_separators, &mut line_column
);
let bits = (byte << 4) >> 2;
match index < len {
true => {
let byte = bytes[index];
index += 1;
add_char(
&mut result, Kind::get_char((bits | (byte >> 6)) as usize, last_chars), &max_line_len, &line_separators,
&mut line_column
);
add_char(
&mut result, Kind::get_char(((byte << 2) >> 2) as usize, last_chars), &max_line_len, &line_separators,
&mut line_column
);
},
false => {
add_char(&mut result, Kind::get_char(bits as usize, last_chars), &max_line_len, &line_separators, &mut line_column);
if must_use_pad {
result.push(PAD_CHAR);
}
break;
},
};
},
false => {
add_char(&mut result, Kind::get_char(bits as usize, last_chars), &max_line_len, &line_separators, &mut line_column);
if must_use_pad {
for _ in 0..2 {
add_char(&mut result, &PAD_CHAR, &max_line_len, &line_separators, &mut line_column);
}
}
break;
},
};
}
result
}
pub fn encode_standard<B>(bytes: B) -> String where B: AsRef<[u8]> {
encode(bytes, Kind::Standard)
}
pub fn encode_imap<B>(bytes: B) -> String where B: AsRef<[u8]> {
encode(bytes, Kind::IMAP)
}
pub fn encode_mime<B>(bytes: B) -> String where B: AsRef<[u8]> {
encode(bytes, Kind::MIME)
}
pub fn encode_url<B>(bytes: B) -> String where B: AsRef<[u8]> {
encode(bytes, Kind::URL)
}
pub fn encode_freenet_url<B>(bytes: B) -> String where B: AsRef<[u8]> {
encode(bytes, Kind::FreenetURL)
}