Struct PollingDispenser 

pub struct PollingDispenser {
    pub metrics: Arc<PollingMetrics>,
    /* private fields */
}

Wraps an inner dispenser and re-executes it until the result body is empty (zero rows). Used for awaiting conditions like SAI index compaction completing.

Configured via op params:

• poll_interval_ms: delay between polls (default: 1000)
• timeout_ms: maximum total wait (default: 300000 = 5 min)
• poll_condition: when to stop: “empty” (default) = stop when 0 rows
• poll_max_error_retries: how many retryable errors to swallow before propagating (default: 0 — strict: any inner error fails the poll immediately, per SRD-03 §“Status-Determination Invariant”)

Per SRD-03 §“Status-Determination Invariant”, this wrapper short-circuits on every non-positive case:

• Positive case: inner op returns OpResult with an empty body → poll succeeds, this dispenser returns success.
• Any other case: inner op returns a non-retryable ExecutionError, OR a retryable error past the retry limit, OR the timeout fires while non-empty bodies are still coming back → this dispenser returns the error, the activity error router sees it, and (under default errors: policy) the phase + the run stop. Errors are never swallowed behind the poll.

Fields

metrics: Arc<PollingMetrics>

Externally visible metrics for the polling operation.

Implementations

impl PollingDispenser

pub fn wrap( inner: Arc<dyn OpDispenser>, poll_interval_ms: u64, timeout_ms: u64, max_error_retries: u32, metric_name: Option<String>, min_rows: u64, max_rows: u64, json_path: Option<String>, ) -> (Arc<dyn OpDispenser>, Arc<PollingMetrics>)

Wrap an inner dispenser with polling behavior. Returns the wrapped dispenser and a handle to the metrics.

metric_name: if set, the elapsed poll time is captured as a named gauge (in seconds) for the summary report. max_error_retries: cap on consecutive retryable inner errors (default 0 = strict).

Trait Implementations

impl OpDispenser for PollingDispenser

fn execute<'a>( &'a self, cycle: u64, ctx: &'a ExecCtx<'a>, ) -> Pin<Box<dyn Future<Output = Result<OpResult, ExecutionError>> + Send + 'a>>

Execute an operation for the given cycle.

fn inner_dispenser(&self) -> Option<&dyn OpDispenser>

Returns the wrapped dispenser when this is a wrapper, None when this is a leaf (the adapter’s base dispenser — e.g. CQL raw / prepared / batch, HTTP, stdout, plotter, …).

fn describe(&self) -> Option<String>

One-line description of the op this dispenser represents — typically the statement text / request shape with bind-point placeholders left unresolved ({table}, {key}, ?, …).

fn describe_resolved(&self, wires: &dyn WireSource) -> Option<String>

Render the actual op the dispenser would fire for the given cycle — the dryrun-equivalent view of the statement after every bind point is interpolated.

fn canonical_kernel(&self) -> Option<&Arc<dyn Kernel>>

SRD-68 invariant I-3 — the dispenser’s canonical Polydat Kernel, established at construction by map_op from its parent — the parent itself, or a kernel bound under it. Any engine: the executor finds the program to bind per fiber by program_id. Returns None for dispensers that don’t own a kernel (adapters with no Polydat needs, or wrappers that delegate to an inner dispenser).

fn adapter_metrics(&self) -> Vec<(String, Labels, MetricValue)>

Snapshot adapter-specific metrics for inclusion in the capture snapshot.

fn status_counters(&self) -> Vec<(&str, u64)>

Adapter-specific status line entries (cumulative, non-destructive read).

fn rows_per_op(&self) -> usize

The op’s uniform per-invocation cursor consumption — how many consecutive wire ordinals one execute call reads and covers.

impl WrappingDispenser for PollingDispenser