Struct BlockSparsePostingList 

pub struct BlockSparsePostingList { /* private fields */ }

Block-based sparse posting list for skip-list style access

Similar to BlockPostingList but stores quantized weights. Includes block-max metadata for Block-Max WAND optimization.

Implementations

impl BlockSparsePostingList

pub fn from_postings( postings: &[(DocId, f32)], quantization: WeightQuantization, ) -> Result<Self>

Build from postings with specified quantization

pub fn from_postings_with_pruning( postings: &[(DocId, f32)], quantization: WeightQuantization, pruning_fraction: Option<f32>, ) -> Result<Self>

Build from postings with static pruning (SEISMIC-style optimization)

If pruning_fraction is Some(f), only the top f*len postings by weight are kept. This exploits “concentration of importance” - top entries preserve most of inner product. Applied only during initial segment build, not during merge.

pub fn serialize<W: Write>(&self, writer: &mut W) -> Result<()>

Serialize to bytes

pub fn deserialize<R: Read>(reader: &mut R) -> Result<Self>

Deserialize from bytes

pub fn doc_count(&self) -> u32

Number of documents

pub fn num_blocks(&self) -> usize

Number of blocks

pub fn quantization(&self) -> WeightQuantization

Get quantization format

pub fn global_max_weight(&self) -> f32

Global maximum weight across all blocks (for MaxScore pruning)

pub fn block_max_weight(&self, block_idx: usize) -> Option<f32>

Get block-max weight for a specific block

pub fn max_contribution(&self, query_weight: f32) -> f32

Compute maximum possible contribution to dot product with given query weight

This is used for MaxScore pruning: if query_weight * global_max_weight < threshold, this entire dimension can be skipped.

pub fn iterator(&self) -> BlockSparsePostingIterator<'_>

Create an iterator

pub fn size_bytes(&self) -> usize

Approximate size in bytes

pub fn concatenate( sources: &[(BlockSparsePostingList, u32)], target_quantization: WeightQuantization, ) -> Result<Self>

Concatenate multiple posting lists with doc_id remapping

pub fn decode_all(&self) -> Result<Vec<(DocId, f32)>>

Decode all postings

Trait Implementations

impl Clone for BlockSparsePostingList

fn clone(&self) -> BlockSparsePostingList

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BlockSparsePostingList

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

Formats the value using the given formatter.