Struct FallbackChainBuilder 

pub struct FallbackChainBuilder { /* private fields */ }

Builder for FallbackChainService.

Services are tried in the order they are added. Add the highest-priority (cheapest / most reliable) service first; add the plugin extraction adapter last as the final fallback.

Example

use std::sync::Arc;
use std::time::Duration;
use stygian_graph::adapters::fallback::FallbackChainBuilder;
use stygian_graph::adapters::noop::NoopService;
use stygian_graph::adapters::resilience::CircuitBreakerImpl;
use stygian_graph::ports::ScrapingService;

let chain = FallbackChainBuilder::new()
    .add(Arc::new(NoopService), CircuitBreakerImpl::new(5, Duration::from_secs(60)))
    .add(Arc::new(NoopService), CircuitBreakerImpl::new(3, Duration::from_secs(30)))
    .named("http-to-plugin")
    .build();

assert_eq!(chain.len(), 2);
assert_eq!(chain.name(), "http-to-plugin");

Implementations

impl FallbackChainBuilder

pub const fn new() -> Self

Create an empty builder with the default name "fallback-chain".

Example

use stygian_graph::adapters::fallback::FallbackChainBuilder;

let builder = FallbackChainBuilder::new();

pub fn add( self, service: Arc<dyn ScrapingService>, breaker: CircuitBreakerImpl, ) -> Self

Add a service and its dedicated circuit breaker (highest to lowest priority).

Arguments

• service — The ScrapingService to add.
• breaker — A CircuitBreakerImpl configured for this specific service.

Example

use std::sync::Arc;
use std::time::Duration;
use stygian_graph::adapters::fallback::FallbackChainBuilder;
use stygian_graph::adapters::noop::NoopService;
use stygian_graph::adapters::resilience::CircuitBreakerImpl;

let builder = FallbackChainBuilder::new()
    .add(Arc::new(NoopService), CircuitBreakerImpl::new(5, Duration::from_secs(60)));

pub const fn named(self, name: &'static str) -> Self

Override the static name reported by ScrapingService::name.

Example

use stygian_graph::adapters::fallback::FallbackChainBuilder;
use stygian_graph::ports::ScrapingService;

let chain = FallbackChainBuilder::new().named("http-to-plugin-fallback").build();
assert_eq!(chain.name(), "http-to-plugin-fallback");

pub fn build(self) -> FallbackChainService

Build the FallbackChainService.

An empty chain (no services added) is valid but will immediately return ServiceError::Unavailable on every call.

Example

use stygian_graph::adapters::fallback::FallbackChainBuilder;

let chain = FallbackChainBuilder::new().build();
assert!(chain.is_empty());

Trait Implementations

impl Default for FallbackChainBuilder

fn default() -> Self

Returns the “default value” for a type.