Struct MiddlewareContext 

pub struct MiddlewareContext {
    pub request_start: Instant,
    pub status_code: u16,
    pub body_size: usize,
    pub sendfile: SendfileState,
    pub compression: CompressionState,
    pub static_response: Option<StaticResponse>,
    pub concurrency_permit: Option<OwnedSemaphorePermit>,
    pub streaming: bool,
    pub trusted_source: bool,
    pub real_client_ip: IpAddr,
}

Context for middleware execution

Stores state needed across middleware chain execution, including request start time, response metadata, and flags.

Fields

request_start: Instant

Request start timestamp (for logging)

status_code: u16

Response status code (captured by logging middleware)

body_size: usize

Response body size (captured by logging middleware)

sendfile: SendfileState

Sendfile state (set by sendfile middleware)

compression: CompressionState

Compression state (set by compression middleware)

static_response: Option<StaticResponse>

Static response (set by static files middleware to short-circuit proxy)

concurrency_permit: Option<OwnedSemaphorePermit>

Concurrency permit (held for request duration, auto-released on drop)

streaming: bool

Streaming flag (set when SSE or other streaming content is detected)

When true, disables response buffering to allow real-time streaming. Automatically set when:

• Content-Type: text/event-stream (Server-Sent Events)
• X-Accel-Buffering: no (nginx compatibility)

trusted_source: bool

Trusted source flag (set by trusted_ranges middleware)

When true, indicates request comes from a trusted proxy/CDN IP range. Used to bypass rate limiting and concurrency limits.

real_client_ip: IpAddr

Real client IP (normalized by trusted_ranges middleware)

Contains the actual client IP extracted from proxy headers (if trusted) or the socket IP (if not from trusted source). Used for:

• Rate limiting (to rate limit real clients, not proxies)
• Logging (to log actual client IPs)
• X-Forwarded-For headers (to maintain proxy chain)

Trait Implementations

impl Default for MiddlewareContext

fn default() -> Self

Returns the “default value” for a type.