Function http_range_headers

nodedb/src/engine/timeseries/packed_partition.rs:425–435

Generate HTTP Range header values for fetching specific columns. Returns `(column_name, "bytes=offset-end")` pairs for use with S3 GetObject or HTTP range requests. Note: for encrypted packed files, these range headers address the ciphertext. Column-level reads require full payload decryption on the client side.

(footer: &PackedFooter, columns: &[&str])

/// ciphertext. Column-level reads require full payload decryption
/// on the client side.
pub fn http_range_headers(footer: &PackedFooter, columns: &[&str]) -> Vec<(String, String)> {
    columns
        .iter()
        .filter_map(|&name| {
            footer.column_ranges.get(name).map(|&(offset, length)| {
                let end = offset + length - 1; // HTTP ranges are inclusive.
                (name.to_string(), format!("bytes={offset}-{end}"))
            })
        })
        .collect()
}

// ── Tests ─────────────────────────────────────────────────────────────────────