Struct MiddlewareChain 

pub struct MiddlewareChain<'m> { /* private fields */ }

A nest of middlewares around a model: [a, b] runs a(b(model)).

Implementations

impl<'m> MiddlewareChain<'m>

pub fn new(layers: Vec<&'m dyn Middleware>) -> Self

Build a chain. The first layer is outermost.

pub fn generate( &self, params: Params, model: &dyn Model, ) -> Result<String, MiddlewareError>

Drive the unary path: transform params front-to-back, then wrap the model generation through the onion.

Errors

Propagates the first MiddlewareError from any layer or the model.

pub fn stream( &self, params: Params, model: &dyn StreamModel, ) -> Result<Vec<String>, MiddlewareError>

Drive the streaming path: transform params front-to-back, then unwind the response stream through the onion, innermost layer first. Each layer’s Middleware::wrap_stream consumes the chunks the next-inner layer emitted; the outermost layer’s emissions are collected and returned.

Between two layers the inner layer’s emitted chunks are buffered before the outer layer consumes them. A single-guardrail chain — the real case — has no inter-layer buffer and streams end-to-end; the guardrail’s own hold-back is exercised regardless.

Errors

Propagates the first MiddlewareError from any layer or the model.