Struct persistent::State

pub struct State<P: Key> { /* fields omitted */ }

Middleware for data that persists between requests with read and write capabilities.

The data is stored behind a RwLock, so multiple read locks can be taken out concurrently.

If most threads need to take out a write lock, you may want to consider Write, which stores the data behind a Mutex, which has a faster locking speed.

State can be linked as BeforeMiddleware to add data to the Request extensions and it can be linked as an AfterMiddleware to add data to the Response extensions.

State also implements Plugin, so the data stored within can be accessed through request.get::<State<P>>() as an Arc<RwLock<P::Value>>.

Methods

impl<P: Key> State<P> where
    P::Value: Send + Sync, 

fn both<T>(start: T) -> (State<P>, State<P>) where
    T: PersistentInto<Arc<RwLock<P::Value>>>, 

Construct a new pair of State that can be passed directly to Chain::link.

The data is initialized with the passed-in value.

fn one<T>(start: T) -> State<P> where
    T: PersistentInto<Arc<RwLock<P::Value>>>, 

Construct a new State that can be passed directly to Chain::link_before or Chain::link_after.

The data is initialized with the passed-in value.

Trait Implementations

impl<P: Key> Clone for State<P> where
    P::Value: Send + Sync, 

fn clone(&self) -> State<P>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<P: Key> Key for State<P> where
    P::Value: 'static, 

type Value = Arc<RwLock<P::Value>>

The value type associated with this key type.

impl<'a, 'b, P: Key> Plugin<Request<'a, 'b>> for State<P> where
    P::Value: Send + Sync, 

type Error = PersistentError

The error type associated with this plugin.

fn eval(
    req: &mut Request<'a, 'b>
) -> Result<Arc<RwLock<P::Value>>, PersistentError>

Create the plugin from an instance of the extended type.

impl<P: Key> BeforeMiddleware for State<P> where
    P::Value: Send + Sync, 

fn before(&self, req: &mut Request) -> IronResult<()>

Do whatever work this middleware should do with a Request object.

fn catch(&self, &mut Request, err: IronError) -> Result<(), IronError>

Respond to an error thrown by a previous BeforeMiddleware.

impl<P: Key> AfterMiddleware for State<P> where
    P::Value: Send + Sync, 

fn after(&self, _: &mut Request, res: Response) -> IronResult<Response>

Do whatever post-processing this middleware should do.

fn catch(&self, &mut Request, err: IronError) -> Result<Response, IronError>

Respond to an error thrown by previous AfterMiddleware, the Handler, or a BeforeMiddleware.