Struct CowEngine 

pub struct CowEngine { /* private fields */ }

COW read/write engine for vector-addressed clusters.

Implementations

impl CowEngine

pub fn new( cluster_size: u32, vectors_per_cluster: u32, bytes_per_vector: u32, ) -> Self

Create a new COW engine.

Panics

Panics if vectors_per_cluster is 0 (would cause division by zero on read/write).

pub fn from_parent( cluster_count: u32, cluster_size: u32, vectors_per_cluster: u32, bytes_per_vector: u32, ) -> Self

Create a COW engine initialized from a parent (all clusters point to parent).

Panics

Panics if vectors_per_cluster is 0 (would cause division by zero on read/write).

pub fn cow_map(&self) -> &CowMap

Get a reference to the underlying COW map.

pub fn read_vector( &self, vector_id: u64, file: &File, parent: Option<&File>, ) -> Result<Vec<u8>, RvfError>

Read a vector by ID. Returns byte slice of vector data.

pub fn read_cluster( &self, cluster_id: u32, file: &File, parent: Option<&File>, ) -> Result<Vec<u8>, RvfError>

Read an entire cluster. Returns cluster data.

pub fn write_vector( &mut self, vector_id: u64, data: &[u8], ) -> Result<(), RvfError>

Write a vector. Handles COW: copies parent slab if inherited.

Writes are buffered for coalescing. Call flush_writes to commit.

pub fn flush_writes( &mut self, file: &mut File, parent: Option<&File>, ) -> Result<Vec<WitnessEvent>, RvfError>

Flush write coalescing buffer. Performs actual slab copies for inherited clusters and applies all pending mutations.

pub fn freeze(&mut self, epoch: u32) -> Result<(), RvfError>

Snapshot-freeze: set epoch, prevent further writes to this generation.

pub fn is_frozen(&self) -> bool

Check if frozen.

pub fn snapshot_epoch(&self) -> u32

Get the snapshot epoch.

pub fn stats(&self) -> CowStats

Get COW statistics.