Function read_blob_batch

crates/paimon/src/arrow/format/blob.rs:179–213

(
    reader: &dyn FileRead,
    blob_index: &BlobFileIndex,
    target_schema: &Arc<arrow_schema::Schema>,
    positions: &[usize],
    project_values: bool,
)

}

async fn read_blob_batch(
    reader: &dyn FileRead,
    blob_index: &BlobFileIndex,
    target_schema: &Arc<arrow_schema::Schema>,
    positions: &[usize],
    project_values: bool,
) -> crate::Result<RecordBatch> {
    if !project_values {
        return RecordBatch::try_new_with_options(
            target_schema.clone(),
            Vec::new(),
            &RecordBatchOptions::new().with_row_count(Some(positions.len())),
        )
        .map_err(|e| Error::UnexpectedError {
            message: format!("Failed to build empty blob RecordBatch: {e}"),
            source: Some(Box::new(e)),
        });
    }

    let planned_reads = plan_blob_reads(blob_index, positions)?;
    let values = fetch_blob_values(reader, planned_reads).await?;
    let mut builder = BinaryBuilder::new();
    for value in values {
        match value {
            BlobValue::Null => builder.append_null(),
            BlobValue::Inline(bytes) => builder.append_value(bytes.as_ref()),
        }
    }

    let columns: Vec<ArrayRef> = vec![Arc::new(builder.finish())];
    RecordBatch::try_new(target_schema.clone(), columns).map_err(|e| Error::UnexpectedError {
        message: format!("Failed to build blob RecordBatch: {e}"),
        source: Some(Box::new(e)),
    })
}

fn plan_blob_reads(
    blob_index: &BlobFileIndex,