Struct PaddedTable 

pub struct PaddedTable { /* private fields */ }

A PQ table that stores pivots grouped by chunk in the following dense, row-major form:

           | -- pivot 0 --    | -- pivot 1 --    | .... | -- pivot K-1 --    |
           +------------------+------------------+------+--------------------+
 chunk 0   | c000 c001 ... 0X | c010 c011 ... 0X | .... | c0K0 c0K1 ...  0X |
 chunk 1   | c100 c101 ... 0X | c110 c111 ... 0X | .... | c1K0 c1K1 ...  0X |
   ...     |       ...        |       ...        | .... |       ...         |
 chunk N-1 | cN00 cN01 ... 0X | cN10 cN11 ... 0X | .... | cNK0 cNK1 ...  0X |

where cCPD is dimension D of pivot P in chunk C, and trailing 0Xs denote potential zero-padding to the SIMD-aligned pivot width.

The member offsets describes the number of unpadded dimensions of each chunk.

Importantly, though, the storage for each pivot is rounded up to a multiple of the runtime system’s preferred SIMD width and all pivots are padded to the same length. This makes distance computations between pivots very fast when computing distances between two product-quantized vectors.

Implementations

impl PaddedTable

pub fn from_basic(basic: BasicTableView<'_>) -> Self

Construct a PaddedTable with the same contents as basic.

pub fn vtable(&self, metric: Metric) -> VTable

Return the distance VTable for the requested Metric.

Note that VTables are generally specific to the PaddedTable that generated them and cannot be reliably shared with different tables.

While this is not a safety issue, incorrect VTables may yield errors due to mismatched SIMD widths.

pub fn ncenters(&self) -> usize

Return the number of PQ centers per chunk.

pub fn nchunks(&self) -> usize

Return the number of PQ chunks.

pub fn dim(&self) -> usize

Return the full-precision dimension expected by this table.

Trait Implementations

impl Clone for PaddedTable

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PaddedTable

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

Formats the value using the given formatter.