Struct CowTrace 

pub struct CowTrace { /* private fields */ }

Copy-on-write trace for efficient memory sharing in MCMC operations.

Most MCMC operations modify only a small number of choices, so CowTrace shares the majority of trace data between states using Arc<BTreeMap>.

Example:

// Convert from regular trace
let cow_trace = CowTrace::from_trace(trace);

// Clone is very efficient (shares memory)
let clone1 = cow_trace.clone();
let clone2 = cow_trace.clone();

// Modification triggers copy-on-write only when needed
let mut modified = clone1.clone();
modified.insert_choice(addr!("new"), Choice {
    addr: addr!("new"),
    value: ChoiceValue::F64(42.0),
    logp: -1.0,
});
// Now `modified` has its own copy, others still share

Implementations

impl CowTrace

pub fn new() -> Self

Create a new copy-on-write trace.

pub fn from_trace(trace: Trace) -> Self

Convert from regular trace.

pub fn to_trace(&self) -> Trace

Convert to regular trace (may involve copying).

pub fn choices_mut(&mut self) -> &mut BTreeMap<Address, Choice>

Get mutable access to choices, copying if necessary.

pub fn insert_choice(&mut self, addr: Address, choice: Choice)

Insert a choice, copying the map if needed.

pub fn choices(&self) -> &BTreeMap<Address, Choice>

Get read-only access to choices.

pub fn total_log_weight(&self) -> f64

Total log weight.

Trait Implementations

impl Clone for CowTrace

fn clone(&self) -> CowTrace

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CowTrace

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

Formats the value using the given formatter.

impl Default for CowTrace

fn default() -> Self

Returns the “default value” for a type.