Struct CMConfig 

pub struct CMConfig {

    pub order1_size: usize,
    pub order2_size: usize,
    pub order3_size: usize,
    pub order4_size: usize,
    pub order5_size: usize,
    pub order6_size: usize,
    pub order7_size: usize,
    pub order8_size: usize,
    pub order9_size: usize,
    pub match_ring_size: usize,
    pub match_hash_size: usize,
    pub word_size: usize,
    pub sparse_size: usize,
    pub run_size: usize,
    pub json_size: usize,
    pub ppm_config: PpmConfig,
}

Configuration for the CM engine – controls memory/quality trade-off.

Each field specifies the ContextMap size in bytes for the corresponding model. Larger sizes reduce hash collisions and improve prediction accuracy at the cost of more memory and slightly slower cache performance.

Fields

order1_size: usize

Order-1 ContextMap size (default: 32MB).

order2_size: usize

Order-2 ContextMap size (default: 16MB).

order3_size: usize

Order-3 ChecksumContextMap size (default: 32MB).

order4_size: usize

Order-4 ChecksumContextMap size (default: 32MB).

order5_size: usize

Order-5 AssociativeContextMap size (default: 32MB).

order6_size: usize

Order-6 AssociativeContextMap size (default: 16MB).

order7_size: usize

Order-7 AssociativeContextMap size (default: 32MB).

order8_size: usize

Order-8 AssociativeContextMap size (default: 32MB).

order9_size: usize

Order-9 AssociativeContextMap size (default: 16MB).

match_ring_size: usize

Match model ring buffer size in bytes (default: 16MB). Must be power of 2.

match_hash_size: usize

Match model hash table entry count (default: 8M). Must be power of 2.

word_size: usize

Word model ContextMap size (default: 16MB).

sparse_size: usize

Sparse model ContextMap size per gap context (default: 8MB, 16MB total).

run_size: usize

Run model ContextMap size (default: 4MB).

json_size: usize

JSON model ContextMap size (default: 8MB).

ppm_config: PpmConfig

PPM model table sizes configuration.

Implementations

impl CMConfig

pub fn balanced() -> Self

Balanced preset: production sizes (~256MB CM + ~360MB PPM).

pub fn max() -> Self

Max preset: 2x everything for better compression (~512MB CM + ~360MB PPM). Doubles all ContextMap sizes, match ring, and hash table. More context slots = fewer collisions = better predictions.

Trait Implementations

impl Clone for CMConfig

fn clone(&self) -> CMConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CMConfig

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

Formats the value using the given formatter.