Struct ReplayEngine 

pub struct ReplayEngine;

Folds a session’s events.jsonl into a ReconstructedState.

Implementations

impl ReplayEngine

pub async fn replay( session_dir: &Path, up_to: Option<u64>, ) -> Result<ReconstructedState, SessionError>

Replay the session log at session_dir.

up_to, if set, is an exclusive upper bound on seq (used by ForkEngine to replay only the prefix being copied). None replays the full log (resume).

Reads the log in bounded chunks (spec §6.2 step 3: ≤ 100 raw envelopes in memory at once) rather than materializing the whole file’s parsed events into one Vec first — unlike Self::fold, which operates on an already-materialized Vec for callers that already hold the events in memory (e.g. llm_condenser.rs, which folds an already-sliced sub-Vec). ForkEngine::fork copies raw events via SessionEventLog::read_all directly and calls this method (not Self::fold) only to validate the cut point.

Errors

Returns SessionError::Io if the log cannot be opened/read.

pub fn fold( events: Vec<SessionEventEnvelope>, up_to: Option<u64>, ) -> ReconstructedState

Fold a sequence of envelopes already read from disk. Exposed separately from Self::replay so callers that already hold the events (e.g. a live SessionActor applying its own just-appended event, or llm_condenser.rs’s condense step folding an already-sliced sub-Vec) can fold incrementally without re-reading the file.