Struct QueryRegistry 

pub struct QueryRegistry { /* private fields */ }

Process-level query registry.

• Allocates unique, non-zero QueryId values.
• Tracks active queries with metadata and weak runtime handles.
• Provides unified cancellation through a per-query CancelReason.
• Responsible for clean teardown: once teardown completes, the query is removed from the registry.

Implementations

impl QueryRegistry

pub fn new() -> Self

pub fn register(&self, metadata: QueryMetadata) -> (QueryId, CancelToken)

Register a new query and obtain its unique QueryId.

The caller should later call Self::unregister once the query lifecycle ends (after teardown).

pub fn register_with_id( &self, requested: QueryId, metadata: QueryMetadata, ) -> (QueryId, CancelToken)

Register a query under a caller-provided ID.

Used to honor a request-scoped query_id (e.g. one supplied by the server layer). If the requested ID is already active or zero, the registry falls back to allocating a fresh unique ID so that identity uniqueness is never violated.

pub fn register_with_token( &self, requested: QueryId, metadata: QueryMetadata, external_token: Option<CancelToken>, ) -> (QueryId, CancelToken)

Register a query with an externally-owned cancellation token.

When external_token is provided, the registry entry shares the same underlying cancellation state, so a CancelToken::cancel performed by the owner (e.g. [QueryContext::mark_killed]) is immediately visible through the registry and vice versa. This is the single-token convergence point for KILL QUERY / cancellation.

pub fn unregister(&self, query_id: QueryId) -> bool

Unregister a completed query.

Returns true if the query was actually registered, false if it was already unknown (harmless — may happen after forced removal).

pub fn cancel( &self, query_id: QueryId, reason: CancelReason, ) -> Option<CancelReason>

Cancel a query with a reason.

Returns the first reason that was set (idempotent — subsequent calls for the same query return None).

pub fn cancel_all(&self, reason: CancelReason) -> Vec<QueryId>

Cancel all active queries with a given reason (used on shutdown).

pub fn cancellation_reason(&self, query_id: QueryId) -> Option<CancelReason>

Check whether a query has been cancelled and get the reason.

pub fn active_count(&self) -> usize

Number of currently active queries.

pub fn active_queries(&self) -> Vec<QueryId>

Iterate over all active query IDs.

Trait Implementations

impl Debug for QueryRegistry

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

Formats the value using the given formatter.

impl Default for QueryRegistry

fn default() -> Self

Returns the “default value” for a type.