Function extract_column_to_arrow

nodedb-strict/src/arrow_extract.rs:31–72

Extract a single column from a batch of tuples into an Arrow `ArrayRef`. `tuples` is a slice of raw tuple byte slices (as stored in redb). `col_idx` is the column index in the schema. Returns an appropriately-typed Arrow array (Int64Array, StringArray, etc.) with a null bitmap derived from the tuples' null bitmaps.

(
    schema: &StrictSchema,
    decoder: &TupleDecoder,
    tuples: &[&[u8]],
    col_idx: usize,
)

/// Returns an appropriately-typed Arrow array (Int64Array, StringArray, etc.)
/// with a null bitmap derived from the tuples' null bitmaps.
pub fn extract_column_to_arrow(
    schema: &StrictSchema,
    decoder: &TupleDecoder,
    tuples: &[&[u8]],
    col_idx: usize,
) -> Result<ArrayRef, StrictError> {
    if col_idx >= schema.columns.len() {
        return Err(StrictError::ColumnOutOfRange {
            index: col_idx,
            count: schema.columns.len(),
        });
    }

    let col_type = &schema.columns[col_idx].column_type;
    let n = tuples.len();

    match col_type {
        ColumnType::Int64 => extract_int64(decoder, tuples, col_idx, n),
        ColumnType::Float64 => extract_float64(decoder, tuples, col_idx, n),
        ColumnType::Bool => extract_bool(decoder, tuples, col_idx, n),
        ColumnType::Timestamp | ColumnType::Timestamptz | ColumnType::SystemTimestamp => {
            extract_timestamp(decoder, tuples, col_idx, n)
        }
        ColumnType::String => extract_string(decoder, tuples, col_idx, n),
        ColumnType::Bytes
        | ColumnType::Geometry
        | ColumnType::Json
        | ColumnType::Array
        | ColumnType::Set
        | ColumnType::Range
        | ColumnType::Record => extract_binary(decoder, tuples, col_idx, n),
        ColumnType::Decimal { .. } => extract_decimal_as_string(decoder, tuples, col_idx, n),
        ColumnType::Uuid => extract_uuid(decoder, tuples, col_idx, n),
        ColumnType::Ulid => extract_uuid(decoder, tuples, col_idx, n), // same 16-byte layout
        ColumnType::Duration => extract_int64(decoder, tuples, col_idx, n), // i64 microseconds
        ColumnType::Regex => extract_string(decoder, tuples, col_idx, n), // stored as string
        ColumnType::Vector(dim) => extract_vector(decoder, tuples, col_idx, n, *dim as usize),
        // ColumnType is #[non_exhaustive]; unknown future types are extracted
        // as binary blobs so Arrow consumers can at least receive raw bytes.
        _ => extract_binary(decoder, tuples, col_idx, n),
    }
}

/// Build a NullBuffer from the null bitmap of N tuples for a given column.
fn build_null_buffer(