44 lines
1.0 KiB
Rust
44 lines
1.0 KiB
Rust
pub fn encode(bytes: &[u8]) -> Vec<u8> {
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let mut encoding = if bytes.first().is_none() {
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return vec![];
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} else {
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vec![*bytes.first().unwrap()]
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};
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let mut occurrences = 1;
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for byte in bytes.iter().skip(1) {
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if byte == encoding.last().unwrap() && occurrences < 255 {
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occurrences += 1;
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} else {
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encoding.extend(&[occurrences, *byte]);
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occurrences = 1;
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}
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}
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encoding.push(occurrences);
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encoding
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}
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/// Read a run-length encoding and return its decoded contents.
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///
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/// * `bytes` - The bytes to be decoded.
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pub fn decode(bytes: &[u8]) -> Vec<u8> {
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let mut decoding = Vec::<u8>::new();
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for (i, byte) in bytes.iter().enumerate() {
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if i % 2 != 0 {
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continue;
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}
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// Repeat bytes[i], bytes[i+1] times in a row.
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// e.g.: "!!" equals to 33 times "!" ("!" value in ASCII).
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for _j in 0..bytes[i + 1] {
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decoding.push(*byte)
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}
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}
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decoding
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}
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