Struct FileSplitStore 

pub struct FileSplitStore { /* private fields */ }

File-backed split store for persistent runs.

Persists assignment metadata, epoch state, and sampler runtime state.

The store always works against a private temporary copy of the source snapshot. All reads and mutations accumulate in the temp file. State is published to permanent storage only when SamplerStateStore::save_sampler_state is called:

• save_to == None → publish temp to save_path (may overwrite).
• save_to == Some(p) → publish temp to p only; save_path is left untouched.

This guarantees that the original source file is never modified and that no partial state leaks to the target before an explicit save.

Implementations

impl FileSplitStore

pub fn open<P: Into<PathBuf>>( path: P, ratios: SplitRatios, seed: u64, ) -> Result<Self, SamplerError>

Open (or create) a file-backed split store at path.

pub fn open_with_load_path<LP: Into<PathBuf>, SP: Into<PathBuf>>( load_path: Option<LP>, save_path: SP, ratios: SplitRatios, seed: u64, ) -> Result<Self, SamplerError>

Open (or create) a file-backed split store at save_path, optionally bootstrapping initial state from load_path.

Always stages through a private temporary file. The source used to seed the temp is chosen as follows:

1. load_path if supplied and it exists.
2. save_path if it already exists.
3. Nothing — a fresh empty store is created in the temp.

All mutations accumulate in the temp. State is published to permanent storage only when SamplerStateStore::save_sampler_state is called. The original source file is never modified.

Trait Implementations

impl Debug for FileSplitStore

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

Formats the value using the given formatter.

impl EpochStateStore for FileSplitStore

fn load_epoch_meta( &self, ) -> Result<HashMap<SplitLabel, PersistedSplitMeta>, SamplerError>

Load split→epoch metadata map.

fn load_epoch_hashes( &self, label: SplitLabel, ) -> Result<Option<PersistedSplitHashes>, SamplerError>

Load persisted epoch hashes for one split, if available.

fn save_epoch_meta( &self, meta: &HashMap<SplitLabel, PersistedSplitMeta>, ) -> Result<(), SamplerError>

Persist split→epoch metadata map.

fn save_epoch_hashes( &self, label: SplitLabel, hashes: &PersistedSplitHashes, ) -> Result<(), SamplerError>

Persist epoch hash list for one split.

impl SamplerStateStore for FileSplitStore

fn save_sampler_state( &self, state: &PersistedSamplerState, save_to: Option<&Path>, ) -> Result<(), SamplerError>

Persist state to the working temp store and publish to the destination.

• save_to == None → publish temp to save_path (may overwrite).
• save_to == Some(p) → publish temp to p only; save_path is left untouched. p must not already exist.

fn load_sampler_state( &self, ) -> Result<Option<PersistedSamplerState>, SamplerError>

Load persisted sampler runtime state, if present.

impl SplitStore for FileSplitStore

fn label_for(&self, id: &RecordId) -> Option<SplitLabel>

Return split label for id if known/derivable.

fn upsert(&self, id: RecordId, label: SplitLabel) -> Result<(), SamplerError>

Persist an explicit split assignment for id.

fn ratios(&self) -> SplitRatios

Return configured split ratios.

fn ensure(&self, id: RecordId) -> Result<SplitLabel, SamplerError>

Return the split label for id, creating/deriving one when needed.