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StoreEngine

exoware_simulator

Trait StoreEngine 

Source 
pub trait StoreEngine:
    Send
    + Sync
    + 'static {
    // Required methods
    fn put_batch(&self, kvs: &[(Bytes, Bytes)]) -> Result<u64, String>;
    fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>, String>;
    fn range_scan(
        &self,
        start: &[u8],
        end: &[u8],
        limit: usize,
        forward: bool,
    ) -> Result<Vec<(Bytes, Bytes)>, String>;
    fn delete_batch(&self, keys: &[&[u8]]) -> Result<u64, String>;
    fn current_sequence(&self) -> u64;
    fn get_batch(
        &self,
        sequence_number: u64,
    ) -> Result<Option<Vec<(Bytes, Bytes)>>, String>;
    fn oldest_retained_batch(&self) -> Result<Option<u64>, String>;
    fn prune_batch_log(&self, cutoff_exclusive: u64) -> Result<u64, String>;

    // Provided method
    fn get_many(
        &self,
        keys: &[&[u8]],
    ) -> Result<Vec<(Vec<u8>, Option<Vec<u8>>)>, String> { ... }
}
Expand description

Implement these operations for your store. All methods must be thread-safe.

Required Methods§

Source

fn put_batch(&self, kvs: &[(Bytes, Bytes)]) -> Result<u64, String>

Persist key-value pairs atomically and return the new global sequence number for this write.

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fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>, String>

Fetch the value for a single key. Returns None when the key does not exist.

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fn range_scan( &self, start: &[u8], end: &[u8], limit: usize, forward: bool, ) -> Result<Vec<(Bytes, Bytes)>, String>

Keys in [start, end] (inclusive) when end is non-empty; empty end means unbounded above. Matches store.query.v1.RangeRequest / ReduceRequest on the wire. limit caps rows returned.

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fn delete_batch(&self, keys: &[&[u8]]) -> Result<u64, String>

Delete a batch of keys atomically. Returns the new global sequence number.

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fn current_sequence(&self) -> u64

Current sequence number visible to readers (used for min_sequence_number checks).

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fn get_batch( &self, sequence_number: u64, ) -> Result<Option<Vec<(Bytes, Bytes)>>, String>

Return the (key, value) pairs written by the put_batch call that was assigned sequence_number. Ok(None) = the batch has been pruned or was never written (the store.stream.v1 service maps None to NOT_FOUND with a BATCH_EVICTED detail).

Engines that don’t retain a batch log return Ok(None) unconditionally, which disables GetBatch and since-cursored Subscribe for that deployment.

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fn oldest_retained_batch(&self) -> Result<Option<u64>, String>

Lowest retained batch sequence number, or None when the batch log is empty. Surfaced in BATCH_EVICTED error details so clients know where to resume from.

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fn prune_batch_log(&self, cutoff_exclusive: u64) -> Result<u64, String>

Delete all batch-log entries with sequence_number < cutoff_exclusive. Returns the number of entries deleted. Invoked only by the compact service’s batch-log policy scope — never by ingest.

Provided Methods§

Source

fn get_many( &self, keys: &[&[u8]], ) -> Result<Vec<(Vec<u8>, Option<Vec<u8>>)>, String>

Batch-get: returns (key, Option<value>) for each input key, preserving order.

Implementors§