Function encode_column_blocks

nodedb-columnar/src/writer/block.rs:22–65

Encode all blocks for a single column, appending to `buf`. Returns per-block statistics.

(
    buf: &mut Vec<u8>,
    col_data: &ColumnData,
    col_type: &ColumnType,
    codec: ResolvedColumnCodec,
    row_count: usize,
    governor: Option<&Arc<MemoryGovernor>>,
)

/// Encode all blocks for a single column, appending to `buf`.
/// Returns per-block statistics.
pub(super) fn encode_column_blocks(
    buf: &mut Vec<u8>,
    col_data: &ColumnData,
    col_type: &ColumnType,
    codec: ResolvedColumnCodec,
    row_count: usize,
    governor: Option<&Arc<MemoryGovernor>>,
) -> Result<Vec<BlockStats>, ColumnarError> {
    let num_blocks = row_count.div_ceil(BLOCK_SIZE);
    let _stats_guard = governor
        .map(|g| {
            g.reserve(
                EngineId::Columnar,
                num_blocks * std::mem::size_of::<BlockStats>(),
            )
        })
        .transpose()?;
    let mut block_stats = Vec::with_capacity(num_blocks);

    for block_idx in 0..num_blocks {
        let start = block_idx * BLOCK_SIZE;
        let end = (start + BLOCK_SIZE).min(row_count);
        let block_row_count = end - start;

        let (compressed, stats) = encode_single_block(
            col_data,
            col_type,
            codec,
            start,
            end,
            block_row_count,
            governor,
        )?;

        // Write block: [compressed_len: u32 LE][compressed_data].
        let len = compressed.len() as u32;
        buf.extend_from_slice(&len.to_le_bytes());
        buf.extend_from_slice(&compressed);

        block_stats.push(stats);
    }

    Ok(block_stats)
}

/// Encode a single block of rows for a column.
fn encode_single_block(