Function encode

nodedb-codec/src/delta.rs:90–109

Encode a slice of i64 values using Delta + ZigZag-varint compression.

(values: &[i64])

/// Encode a slice of i64 values using Delta + ZigZag-varint compression.
pub fn encode(values: &[i64]) -> Vec<u8> {
    let count = values.len() as u32;
    // Estimate: header(4) + first_value(8) + ~2 bytes per delta.
    let mut out = Vec::with_capacity(12 + values.len() * 2);

    out.extend_from_slice(&count.to_le_bytes());

    if values.is_empty() {
        return out;
    }

    out.extend_from_slice(&values[0].to_le_bytes());

    for i in 1..values.len() {
        let delta = values[i].wrapping_sub(values[i - 1]);
        write_varint(&mut out, zigzag_encode(delta));
    }

    out
}

/// Decode Delta-compressed bytes back to i64 values.
pub fn decode(data: &[u8]) -> Result<Vec<i64>, CodecError> {