Struct ReadView 

pub struct ReadView { /* private fields */ }

Owns all resources needed to read; it can outlive the Store and be shared with asynchronous providers without self-referential borrowed lifetimes.

Implementations

impl ReadView

pub fn planner_stats_cache(&self) -> &PlannerStats

The store’s planner-statistics cache. Estimates only; exact answers never come from it.

pub fn owner_sets(&self) -> &OwnerSets

The store’s owner-set cache, keyed by this view’s commit index.

pub fn belongs_to(&self, store: &Store) -> bool

Process-local Store identity, independent of tenant and commit index. Prevents accidentally pairing a view with another engine’s catalogs.

pub fn commit_index(&self) -> u64

Commit index this view reads at.

pub fn deriver(&self) -> Option<&Arc<dyn Deriver>>

The store’s apply-time deriver, if one is installed.

pub fn cancellation(&self) -> ReadCancellation

A cloneable handle to this view’s cancellation flag.

pub fn with_materialization_limit( self: &Arc<Self>, bytes: usize, ) -> Arc<ReadView>

Create a child view over this exact pinned snapshot with narrower per-item and materialized-prefix limits. The child has its own limits, while cancellation remains shared with the parent.

pub fn check_cancelled(&self) -> Result<(), StorageError>

Check cancellation between non-storage operations (for example, serializing output) without performing an otherwise unnecessary read.

Errors

Returns StorageError::Cancelled if the view has been cancelled.

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

Read a single key at this view’s snapshot.

Errors

Returns StorageError if the view is cancelled, the item exceeds the read limit, or the backend read fails.

pub fn range_prefix( &self, prefix: &[u8], ) -> Result<Vec<(Vec<u8>, Vec<u8>)>, StorageError>

Transitional materializing helper for consumers migrating to cursors. The local ceiling is not a substitute for shared query admission.

Errors

Returns StorageError if the view is cancelled, the item exceeds the read limit, or the materialized result exceeds the 64 MiB ceiling.

Panics

Panics if a key/value projection batch unexpectedly yields a row without a value.

pub fn range( &self, start: &[u8], end: &[u8], ) -> Result<Vec<(Vec<u8>, Vec<u8>)>, StorageError>

Materialize every key/value pair with start <= key < end, in key order. An empty end means unbounded above. Shares the prefix path’s aggregate materialization ceiling.

Errors

Returns StorageError if the view is cancelled, the item exceeds the read limit, or the materialized result exceeds the 64 MiB ceiling.

pub fn scan( &self, bounds: ScanBounds, projection: ScanProjection, ) -> Result<ScanCursor<'_>, StorageError>

Open a forward scan cursor over bounds with the given projection.

Errors

Returns StorageError::Cancelled if the view is cancelled, StorageError::InvalidRead if the bounds are inverted, or StorageError::ResourceExhausted if a bound key exceeds the read limit.

Trait Implementations

impl DeriveRead for ReadView

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

Current value of key, or None when absent.

fn range_prefix( &self, prefix: &[u8], ) -> Result<Vec<(Vec<u8>, Vec<u8>)>, StorageError>

Every live (key, value) whose key starts with prefix, in key order.

fn range( &self, start: &[u8], end: &[u8], ) -> Result<Vec<(Vec<u8>, Vec<u8>)>, StorageError>

Every live (key, value) with start <= key < end, in key order. An empty end is unbounded above.

impl Drop for ReadView

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.