Function extract_vector

nodedb-strict/src/arrow_extract.rs:338–369

Vector columns → BinaryArray of packed f32 bytes. Each entry is `dim * 4` bytes of packed little-endian f32.

(
    decoder: &TupleDecoder,
    tuples: &[&[u8]],
    col_idx: usize,
    n: usize,
    dim: usize,
)

/// Vector columns → BinaryArray of packed f32 bytes.
/// Each entry is `dim * 4` bytes of packed little-endian f32.
fn extract_vector(
    decoder: &TupleDecoder,
    tuples: &[&[u8]],
    col_idx: usize,
    n: usize,
    dim: usize,
) -> Result<ArrayRef, StrictError> {
    let (null_buf, null_count) = build_null_buffer(decoder, tuples, col_idx)?;
    let vec_size = dim * 4;
    let mut blobs: Vec<Option<&[u8]>> = Vec::with_capacity(n);

    for tuple in tuples {
        if let Some(raw) = decoder.extract_fixed_raw(tuple, col_idx)? {
            blobs.push(Some(&raw[..vec_size]));
        } else {
            blobs.push(None);
        }
    }

    let array = BinaryArray::from(blobs);
    if null_count > 0 {
        let data = array
            .into_data()
            .into_builder()
            .null_bit_buffer(Some(null_buf.into_inner().into_inner()))
            .build()
            .expect("arrow array builder lengths are consistent");
        Ok(Arc::new(BinaryArray::from(data)))
    } else {
        Ok(Arc::new(array))
    }
}

#[cfg(test)]
mod tests {