Struct SparseMastForest 

pub struct SparseMastForest { /* private fields */ }

A sparse replay view over a single source MastForest’s MastNodeId space, retaining only the nodes visited during execution.

Unlike MastForest, which stores nodes contiguously in an IndexVec, a SparseMastForest uses a BTreeMap so that it can preserve the original MastNodeIds of the source forest while omitting nodes that were not visited. A SparseMastForest is not an independent forest shape: it shares its source forest’s ID space, and is intended to back re-execution of the same program. Lookups by the original MastNodeId continue to resolve to the correct MastNodes.

In addition to the visited nodes, a SparseMastForest may also carry digest-only entries for nodes that were referenced during execution but never actually entered (e.g. the not-taken branch of a split, or the children of a join that only need to contribute their digests to the parent’s trace row). These entries let trace generation read the digest without having to copy the full child node, and they make accidental entry into a pruned node a clean get_node_by_id miss rather than a partially-populated node.

Implementations

impl SparseMastForest

pub fn nodes(&self) -> &BTreeMap<MastNodeId, MastNode>

Returns the underlying nodes of this sparse forest, keyed by their original MastNodeId.

pub fn num_nodes(&self) -> usize

Returns the minimum node count needed to cover all IDs retained in this sparse replay view.

This is not the number of visited nodes and may be smaller than the source MastForest’s node count when high source IDs were not needed during replay.

pub fn procedure_roots(&self) -> &[MastNodeId]

Returns the roots of procedures defined within this sparse forest.

pub fn advice_map(&self) -> &AdviceMap

Returns the empty advice map associated with this sparse forest.

Sparse replay uses AdviceReplay for advice reads; this map remains empty to satisfy the shared ExecutableMastForest interface.

Trait Implementations

impl Debug for SparseMastForest

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

Formats the value using the given formatter.

impl Deserializable for SparseMastForest

fn read_from_bytes( bytes: &[u8], ) -> Result<SparseMastForest, DeserializationError>

Reads one trusted sparse replay payload and rejects trailing bytes.

This is not an untrusted input format. The reader performs cheap structural checks, but a producer controls collection lengths and can drive allocation. Callers must only read these bytes from a trusted producer, or after an outer transport/authentication layer has accepted them.

fn read_from<R>( source: &mut R, ) -> Result<SparseMastForest, DeserializationError>

where R: ByteReader,

Reads a sequence of bytes from the provided source, attempts to deserialize these bytes into Self, and returns the result.

fn min_serialized_size() -> usize

Returns the minimum serialized size for one instance of this type.

fn read_from_bytes_with_budget( bytes: &[u8], budget: usize, ) -> Result<Self, DeserializationError>

Deserializes Self from bytes with a byte budget limit.

impl ExecutableMastForest for SparseMastForest

fn get_node_by_id(&self, node_id: MastNodeId) -> Option<&MastNode>

Returns the MastNode associated with the provided MastNodeId if present, or else None.

fn get_digest_by_id(&self, node_id: MastNodeId) -> Option<Word>

Returns the digest of the node associated with the provided MastNodeId if present, or else None.

fn find_procedure_root(&self, digest: Word) -> Option<MastNodeId>

Returns the MastNodeId of the procedure associated with a given digest, if any.

fn advice_map(&self) -> &AdviceMap

Returns the advice map associated with this forest.

impl Serializable for SparseMastForest

fn write_into<W>(&self, target: &mut W)

where W: ByteWriter,

Serializes self into bytes and writes these bytes into the target.

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

Serializes self into a vector of bytes.

fn get_size_hint(&self) -> usize

Returns an estimate of how many bytes are needed to represent self.