Enum PostingFormat 

pub enum PostingFormat {
    Bitpacked,
    SimdBp128,
    EliasFano,
    PartitionedEF,
    Roaring,
}

Posting list format selector

Variants

Bitpacked

Standard bitpacked format (default for small lists)

SimdBp128

SIMD-BP128 with vertical layout (medium lists, fast decoding)

EliasFano

Elias-Fano for long posting lists

PartitionedEF

Partitioned Elias-Fano (very long lists, better compression)

Roaring

Roaring bitmap for very frequent terms

Implementations

impl PostingFormat

pub fn select(doc_count: usize, total_docs: usize) -> Self

Select optimal format based on posting list characteristics

Simplified format selection (based on benchmarks):

• Very frequent (>1% of corpus, >20K docs): Roaring (fastest iteration, set ops)
• Large (≥20K docs): Partitioned EF (best compression 15.9%)
• All other lists: SIMD-BP128 (fastest decoding 198K ints/μs, optimal compression 16.3%)

Note: SIMD-BP128 replaces both Bitpacked and plain Elias-Fano as it has:

• Same compression as Bitpacked (16.3%)
• Faster decoding than Bitpacked (198K vs 192K ints/μs)
• Much faster than Elias-Fano (198K vs 9.6K ints/μs)

Trait Implementations

impl Clone for PostingFormat

fn clone(&self) -> PostingFormat

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PostingFormat

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

Formats the value using the given formatter.

impl PartialEq for PostingFormat

fn eq(&self, other: &PostingFormat) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for PostingFormat

impl Eq for PostingFormat

impl StructuralPartialEq for PostingFormat