Module graphql_throttle 

Proactive cost-throttle management for GraphQL APIs Proactive GraphQL cost-throttle management.

LiveBudget tracks the rolling point budget advertised by APIs that implement the Shopify / Jobber-style cost-throttle extension envelope:

{ "extensions": { "cost": {
    "requestedQueryCost": 12,
    "actualQueryCost": 12,
    "throttleStatus": {
        "maximumAvailable": 10000.0,
        "currentlyAvailable": 9988.0,
        "restoreRate": 500.0
    }
}}}

Before each request a proactive pre-flight delay is computed: if the projected available budget (accounting for elapsed restore time and in-flight reservations) will be too low, the caller sleeps until it recovers. After the delay, pre_flight_reserve atomically reserves an estimated cost against the budget so concurrent callers immediately see a reduced balance.

BudgetGuard (RAII)

BudgetGuard wraps pre_flight_reserve + release_reservation into a scope-based guard so callers no longer need to track every exit path manually. Call BudgetGuard::acquire before the request and BudgetGuard::release on the success path. If release() is never called (e.g. early return or ? propagation), the Drop impl spawns a background task to release the reservation as a safety net.

use stygian_graph::adapters::graphql_throttle::{
    CostThrottleConfig, PluginBudget, BudgetGuard,
};

let budget = PluginBudget::new(CostThrottleConfig::default());
let guard = BudgetGuard::acquire(&budget).await;
// ... send request ...
guard.release().await; // explicit async release on success path
// If this line is never reached, Drop releases via tokio::spawn.

Re-exports

pub use crate::ports::graphql_plugin::CostThrottleConfig;

Structs

BudgetGuard

RAII guard that automatically releases a budget reservation on drop.

LiveBudget

Mutable runtime state tracking the current point budget.

PluginBudget

A shareable, cheaply-cloneable handle to a per-plugin LiveBudget.

Functions

pre_flight_reserve

Sleep if the projected budget is too low, then atomically reserve an estimated cost for the upcoming request.

reactive_backoff_ms

Compute the reactive back-off delay from a throttle response body.

release_reservation

Release a reservation made by pre_flight_reserve.

update_budget

Update the PluginBudget from a completed response body.