Struct gotham::state::State

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pub struct State { /* private fields */ }
Expand description

Provides storage for request state, and stores one item of each type. The types used for storage must implement the StateData trait to allow its storage, which is usually done by adding #[derive(StateData)] on the type in question.

Examples

use gotham::state::{State, StateData};

#[derive(StateData)]
struct MyStruct {
    value: i32,
}
state.put(MyStruct { value: 1 });
assert_eq!(state.borrow::<MyStruct>().value, 1);

Implementations§

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impl State

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pub fn from_request(req: Request<Body>, client_addr: SocketAddr) -> Self

Instantiate a new State for a given Request. This is primarily useful if you’re calling Gotham from your own Hyper service.

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pub fn put<T>(&mut self, t: T)where T: StateData,

Puts a value into the State storage. One value of each type is retained. Successive calls to put will overwrite the existing value of the same type.

Examples
state.put(MyStruct { value: 1 });
assert_eq!(state.borrow::<MyStruct>().value, 1);

state.put(AnotherStruct { value: "a string" });
state.put(MyStruct { value: 100 });

assert_eq!(state.borrow::<AnotherStruct>().value, "a string");
assert_eq!(state.borrow::<MyStruct>().value, 100);
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pub fn has<T>(&self) -> boolwhere T: StateData,

Determines if the current value exists in State storage.

Examples
state.put(MyStruct { value: 1 });
assert!(state.has::<MyStruct>());
assert_eq!(state.borrow::<MyStruct>().value, 1);

assert!(!state.has::<AnotherStruct>());
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pub fn try_borrow<T>(&self) -> Option<&T>where T: StateData,

Tries to borrow a value from the State storage.

Examples
state.put(MyStruct { value: 1 });
assert!(state.try_borrow::<MyStruct>().is_some());
assert_eq!(state.try_borrow::<MyStruct>().unwrap().value, 1);

assert!(state.try_borrow::<AnotherStruct>().is_none());
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pub fn borrow<T>(&self) -> &Twhere T: StateData,

Borrows a value from the State storage.

Panics

If a value of type T is not present in State.

Examples
state.put(MyStruct { value: 1 });
assert_eq!(state.borrow::<MyStruct>().value, 1);
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pub fn try_borrow_mut<T>(&mut self) -> Option<&mut T>where T: StateData,

Tries to mutably borrow a value from the State storage.

Examples
state.put(MyStruct { value: 100 });

if let Some(a) = state.try_borrow_mut::<MyStruct>() {
    a.value += 10;
}

assert_eq!(state.borrow::<MyStruct>().value, 110);

assert!(state.try_borrow_mut::<AnotherStruct>().is_none());
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pub fn borrow_mut<T>(&mut self) -> &mut Twhere T: StateData,

Mutably borrows a value from the State storage.

Panics

If a value of type T is not present in State.

Examples
state.put(MyStruct { value: 100 });

{
    let a = state.borrow_mut::<MyStruct>();
    a.value += 10;
}

assert_eq!(state.borrow::<MyStruct>().value, 110);

assert!(state.try_borrow_mut::<AnotherStruct>().is_none());
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pub fn try_take<T>(&mut self) -> Option<T>where T: StateData,

Tries to move a value out of the State storage and return ownership.

Examples
state.put(MyStruct { value: 110 });

assert_eq!(state.try_take::<MyStruct>().unwrap().value, 110);

assert!(state.try_take::<MyStruct>().is_none());
assert!(state.try_borrow_mut::<MyStruct>().is_none());
assert!(state.try_borrow::<MyStruct>().is_none());

assert!(state.try_take::<AnotherStruct>().is_none());
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pub fn take<T>(&mut self) -> Twhere T: StateData,

Moves a value out of the State storage and returns ownership.

Panics

If a value of type T is not present in State.

Examples
state.put(MyStruct { value: 110 });

assert_eq!(state.take::<MyStruct>().value, 110);

assert!(state.try_take::<MyStruct>().is_none());
assert!(state.try_borrow_mut::<MyStruct>().is_none());
assert!(state.try_borrow::<MyStruct>().is_none());

Auto Trait Implementations§

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impl !RefUnwindSafe for State

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impl Send for State

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impl !Sync for State

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impl Unpin for State

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impl !UnwindSafe for State

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more