Struct QueryManager 

pub struct QueryManager { /* private fields */ }

Manages multiple in-flight queries in parallel using promises.

Tracks queries by unique ID (typically a pane ID), enabling Grafana-style parallel refresh where all panels query simultaneously.

Includes timeout detection to prevent queries from hanging indefinitely.

Example

let mut manager = QueryManager::new();

// Fire multiple queries in parallel
manager.execute(pane_id_1, &client, request1, &ctx);
manager.execute(pane_id_2, &client, request2, &ctx);

// In update loop, poll for all completed results
for (id, result) in manager.poll_all() {
    // Handle result for pane with this id
}

Implementations

impl QueryManager

pub fn new() -> Self

Create a new query manager with the default timeout.

pub fn with_timeout(timeout_secs: u64) -> Self

Create a new query manager with a custom timeout.

pub fn is_querying(&self) -> bool

Check if any queries are currently in flight.

pub fn is_querying_id(&self, id: usize) -> bool

Check if a specific query is in flight.

pub fn pending_count(&self) -> usize

Get the number of queries currently in flight.

pub fn execute<C: MetricsClient + ?Sized>( &mut self, id: usize, client: &C, request: QueryRequest, ctx: &Context, )

Execute a query for the given ID using the given client.

If a query for this ID is already in flight, it is cancelled and replaced. Call poll_all() each frame to check for results.

pub fn poll_all(&mut self) -> Vec<(usize, QueryResult)>

Poll for all completed query results.

Returns a vector of (id, result) pairs for queries that completed or timed out. Completed queries are removed from the pending set.

pub fn cancel(&mut self, id: usize)

Cancel a specific query by ID.

Note: This doesn’t actually cancel the HTTP request, but it will ignore the result when it arrives.

pub fn cancel_all(&mut self)

Cancel all pending queries.

Trait Implementations

impl Default for QueryManager

fn default() -> Self

Returns the “default value” for a type.