Struct DataFilePart 

pub struct DataFilePart { /* private fields */ }

A complete ordinary Lance file validated for data-file concatenation.

A part is independently readable and is not an incomplete file-format fragment or a persisted Manifest entity. Opening one reads its real footer, verifies that its physical columns form a complete rectangular file, and checks Blob v2 descriptors against the caller-provided ID lease. Parts with Blob v2 columns are also bound to the caller-provided BlobTargetId.

This runtime value has no fragment, source-row, range, dataset, or storage identity. Lance defines no serialization or recovery contract for it. The caller owns the input storage and must keep every Blob-bearing part associated with the dataset and base where its managed payloads were written. The order passed to concat_data_file_parts determines final physical row order.

Example

use lance_file::concat::{DataFilePart, EncodedFileInput};
use lance_io::scheduler::FileScheduler;

let part = DataFilePart::open(EncodedFileInput::new(file), None, None).await?;
println!("part rows: {}", part.num_rows());

Implementations

impl DataFilePart

pub async fn open( input: EncodedFileInput, blob_ids: Option<Range<u32>>, blob_target_id: Option<BlobTargetId>, ) -> Result<Self>

Open and validate one complete encoded file.

blob_ids is the half-open ID range leased to this part. Managed Packed and Dedicated descriptors must fall inside it. blob_target_id associates the part with one final target for runtime equality checks and is required whenever the part contains Blob v2 columns. It does not prove that the target belongs to a particular dataset or storage namespace. Non-empty Inline Blob v2 descriptors and legacy Blob v1 columns are rejected because their payload locations cannot be reused in a different data file.

pub fn num_rows(&self) -> u64

Number of physical rows described by the part footer.

Trait Implementations

impl Clone for DataFilePart

fn clone(&self) -> DataFilePart

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DataFilePart

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.