Trait RoutingSpi 

pub trait RoutingSpi:
    Send
    + Sync
    + 'static {
    // Required method
    async fn route(
        &self,
        ctx: &RequestCtx<'_>,
    ) -> Result<RouteDecision, SpiError>;
}

Decides where and how a single request is routed.

This is the low-level contract for a single routing decision: full control over the destination and the transforms. Most implementers instead provide a crate::TenancySpi, which osproxy-tenancy adapts into a RoutingSpi.

Note this yields only a RouteDecision. The engine pipeline needs more than a decision (the resolved partition, epoch, and migration phase, to construct ids, demux bulk, and gate writes), so it is generic over the richer osproxy_tenancy::Router seam rather than this trait. Implement Router to drive the engine with custom routing; implement RoutingSpi where only a RouteDecision is required.

Invariants

• MUST resolve to exactly one Target, no synchronous fan-out in v1 (ADR-002).
• MUST NOT panic; return SpiError for every failure (NFR-R1).
• The returned RouteDecision::epoch MUST come from the placement state the decision was derived from, so the sink can detect a stale-epoch write during a migration (docs/06 §2).

The engine drives implementations through generics (monomorphized, no dyn dispatch on the hot path), so the future’s Send-ness is checked at the spawn site.

Examples

use osproxy_core::{ClusterId, Epoch, IndexName, Target};
use osproxy_spi::{Protocol, RequestCtx, RouteDecision, RoutingSpi, SpiError};

struct PinToOne;

impl RoutingSpi for PinToOne {
    async fn route(&self, _ctx: &RequestCtx<'_>) -> Result<RouteDecision, SpiError> {
        let target = Target::new(ClusterId::from("only"), IndexName::from("logs"));
        Ok(RouteDecision::passthrough(target, Protocol::Http1, Epoch::ZERO))
    }
}

Required Methods

async fn route(&self, ctx: &RequestCtx<'_>) -> Result<RouteDecision, SpiError>

Resolves the routing decision for an authenticated request.

Errors

Returns SpiError when the partition cannot be resolved, no placement exists, the placement backend is unavailable, or the endpoint is unsupported.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors