Struct EventStoreReader 

pub struct EventStoreReader<B> { /* private fields */ }

Read-only handle over an EventStore backend.

The reader is the canonical entry point for read-only replay, audit, and verifier scans: it never mutates the backend (no append_batch surface) and it tolerates running and sealed backends uniformly.

Implementations

impl<B: EventStore> EventStoreReader<B>

pub const fn new(backend: B) -> Self

Wraps backend for read-only access.

pub fn manifest(&self) -> Result<RunManifest, EventStoreError>

Returns the manifest of the open run.

Errors

Returns an error if no run is open.

pub fn high_watermark(&self) -> Result<u64, EventStoreError>

Returns the largest seq durably acknowledged for the open run.

Errors

Returns an error if no run is open.

pub fn scan_seq( &self, seq: u64, ) -> Result<Option<EventStoreEntry>, EventStoreError>

Reads a single entry by seq.

Returns None when seq == 0 or seq exceeds the current high-watermark.

Errors

Returns an error if the recomputed entry hash diverges from the stored value, if the row is missing inside the high-watermark, or if the backend fails.

pub fn lookup( &self, kind: IndexKind, key: &str, ) -> Result<Option<u64>, EventStoreError>

Looks up the first seq recorded under the given index key.

Errors

Returns an error if the backend fails.

pub fn latest_snapshot_anchor( &self, ) -> Result<Option<SnapshotAnchor>, EventStoreError>

Returns the latest snapshot anchor for the run.

Returns Ok(None) when no snapshot anchor has been recorded yet.

Errors

Returns an error if no run is open or the backend does not support snapshot anchors, or if a stored anchor cannot decode.

pub fn snapshot_replay_plan( &self, ) -> Result<SnapshotReplayPlan, EventStoreError>

Builds the restore replay bounds from the latest snapshot anchor.

Restore callers fetch and validate the cache-owned snapshot blob first, then replay entries in [from_seq, to_seq]. When an anchor exists, from_seq is anchor.high_watermark + 1; without an anchor, restore replays from seq 1.

Errors

Returns an error if no run is open or the backend does not support snapshot anchors, or if the stored anchor points past the durable high-watermark.

pub fn scan_snapshot_replay_tail( &self, ) -> Result<(SnapshotReplayPlan, RangeScan<'_>), EventStoreError>

Scans the forward replay tail after the latest snapshot anchor.

This pairs Self::snapshot_replay_plan with the actual event iterator used by restore: entries start at anchor.high_watermark + 1 when an anchor exists, or at seq 1 when no cache snapshot has been anchored.

Errors

Returns an error if Self::snapshot_replay_plan fails.

pub fn scan_range( &self, from: u64, to: u64, direction: ScanDirection, ) -> RangeScan<'_>

Scans entries by seq over the inclusive range [from, to].

The returned iterator pulls DEFAULT_SCAN_CHUNK_SIZE entries at a time from the backend so a multi-million-entry forensics scan keeps the working set bounded while still amortizing per-transaction overhead. The iterator yields one entry per call; backend errors surface as Some(Err(...)) and terminate the scan.

pub fn scan_range_chunked( &self, from: u64, to: u64, direction: ScanDirection, chunk_size: u64, ) -> RangeScan<'_>

Variant of Self::scan_range with a caller-chosen chunk size.

chunk_size == 0 is normalized to 1; the reader never asks the backend for a degenerate empty window because the chunk window is the only progress signal the iterator advances on.

pub fn into_inner(self) -> B

Returns the underlying backend, consuming the reader.

pub const fn backend(&self) -> &B

Returns a reference to the underlying backend.

Trait Implementations

impl<B: Debug> Debug for EventStoreReader<B>

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

Formats the value using the given formatter.