Struct EwahBitmap 

pub struct EwahBitmap {
    pub bit_size: u32,
    pub words: Vec<u64>,
    pub rlw_position: u32,
}

Fields

bit_size: u32

words: Vec<u64>

rlw_position: u32

Implementations

impl EwahBitmap

pub fn from_words(bit_size: u32, words: &[u64]) -> Result<Self>

Constructs an EwahBitmap in git’s canonical EWAH compressed form from a slice of raw uncompressed 64-bit words.

Within each word bit i corresponds to position word_index * 64 + i, matching git’s on-disk convention. bit_size records the number of logical bits the bitmap spans; it must not exceed words.len() * 64.

This mirrors libgit’s ewah_add/ewah_add_empty_words incremental encoder: consecutive all-zero or all-one words collapse into a run, and any other word is stored verbatim as a literal. Only the first bit_size.div_ceil(64) words back the declared bits; any extra trailing words supplied by the caller are ignored, just as git encodes a bitmap sized to its highest set bit.

pub fn from_positions(bit_size: u32, positions: &[u32]) -> Result<Self>

Constructs an EwahBitmap from a set of bit positions.

bit_size is the number of logical bits (typically the pack object count). Every position in positions must be strictly less than bit_size. Positions may be given in any order and may repeat.

pub fn empty() -> Self

An empty EWAH bitmap (no bits, no words). This is what git writes for an all-zero type bitmap (e.g. when a pack has no tags).

pub fn to_words(&self) -> Result<Vec<u64>>

Decodes the compressed EWAH back into raw 64-bit words, LSB-first within each word. The returned vector has bit_size.div_ceil(64) entries.

This is the inverse of EwahBitmap::from_words for the bits the bitmap actually covers and is primarily used to validate roundtrips.

pub fn to_positions(&self) -> Result<Vec<u32>>

Returns the sorted set bit positions covered by this bitmap.

pub fn to_bytes(&self) -> Vec<u8>

Serialises the bitmap to git’s on-disk EWAH byte layout: bit_size (u32 BE), word count (u32 BE), each compressed word (u64 BE), then the running-length-word position (u32 BE).

Trait Implementations

impl Clone for EwahBitmap

fn clone(&self) -> EwahBitmap

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EwahBitmap

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

Formats the value using the given formatter.

impl Eq for EwahBitmap

impl PartialEq for EwahBitmap

fn eq(&self, other: &EwahBitmap) -> 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 StructuralPartialEq for EwahBitmap