Struct BasicTableBase 

pub struct BasicTableBase<T, U>
where
    T: DenseData<Elem = f32>,
    U: DenseData<Elem = usize>,
{ /* private fields */ }

A basic PQ table that stores the pivot table in the following dense, row-major form:

          | -- chunk 0 -- | -- chunk 1 -- | -- chunk 2 -- | .... | -- chunk N-1 -- |
          +------------------------------------------------------------------------+
 pivot 0  | c000 c001 ... | c010 c011 ... | c020 c021 ... | .... |       ...       |
 pivot 1  | c100 c101 ... | c110 c111 ... | c120 c121 ... | .... |       ...       |
   ...    |      ...      |      ...      |      ...      | .... |       ...       |
 pivot K  | cK00 cK01 ... | cK10 cK11 ... | cK20 cK21 ... | .... |       ...       |

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

Invariants

• offsets.dim() == pivots.nrows(): The dimensionality of the two must agree.

Implementations

impl<T, U> BasicTableBase<T, U>

where T: DenseData<Elem = f32>, U: DenseData<Elem = usize>,

pub fn new( pivots: MatrixBase<T>, offsets: ChunkOffsetsBase<U>, ) -> Result<Self, BasicTableError>

Construct a new BasicTableBase over the pivot table and offsets.

Error

Returns an error if pivots.ncols() != offsets.dim() or if pivots.nrows() == 0.

pub fn view_pivots(&self) -> MatrixView<'_, f32>

Return a view over the pivot table.

pub fn view_offsets(&self) -> ChunkOffsetsView<'_>

Return a view over the schema offsets.

pub fn ncenters(&self) -> usize

Return the number of pivots in each PQ chunk.

pub fn nchunks(&self) -> usize

Return the number of PQ chunks.

pub fn dim(&self) -> usize

Return the dimensionality of the full-precision vectors associated with this table.

Trait Implementations

impl<T, U> Clone for BasicTableBase<T, U>

where T: DenseData<Elem = f32> + Clone, U: DenseData<Elem = usize> + Clone,

fn clone(&self) -> BasicTableBase<T, U>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T, U> CompressInto<&[f32], &mut [u8]> for BasicTableBase<T, U>

where T: DenseData<Elem = f32>, U: DenseData<Elem = usize>,

fn compress_into(&self, from: &[f32], to: &mut [u8]) -> Result<(), Self::Error>

Compress the full-precision vector from into the PQ byte buffer to.

Compression is performed by partitioning from into chunks according to the offsets schema in the table and then finding the closest pivot according to the L2 distance.

The final compressed value is the index of the closest pivot.

Errors

Returns errors under the following conditions:

• self.ncenters() > 256: If the number of centers exceeds 256, then it cannot be guaranteed that the index of the closest pivot for a chunk will fit losslessly in an 8-bit integer.

• from.len() != self.dim(): The full precision vector must have the dimensionality expected by the compression.

• to.len() != self.nchunks(): The PQ buffer must be sized appropriately.

• If any chunk is sufficiently far from all centers that its distance becomes infinity to all centers.

Allocates

This function should not allocate when successful.

Parallelism

This function is single-threaded.

type Error = TableCompressionError

Errors that may occur during compression.

type Output = ()

An output type resulting from compression.

impl<T, U> Debug for BasicTableBase<T, U>

where T: DenseData<Elem = f32> + Debug, U: DenseData<Elem = usize> + Debug,

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

Formats the value using the given formatter.