Struct Depot 

pub struct Depot { /* private fields */ }

Store temporary data for the current request.

A Depot is created when the server processes a request from a client, and dropped when all processing for the request is finished.

Example

We set the current_user value in function set_user, and then use this value in the following middlewares and handlers.

use salvo_core::prelude::*;

#[handler]
async fn set_user(depot: &mut Depot) {
    depot.insert("user", "client");
}
#[handler]
async fn hello(depot: &mut Depot) -> String {
    format!(
        "Hello {}",
        depot.get::<&str>("user").copied().unwrap_or_default()
    )
}

#[tokio::main]
async fn main() {
    let router = Router::new().hoop(set_user).goal(hello);
    let acceptor = TcpListener::new("0.0.0.0:8698").bind().await;
    Server::new(acceptor).serve(router).await;
}

Implementations

impl Depot

pub fn new() -> Self

Creates an empty Depot.

The depot is initially created with a capacity of 0, so it will not allocate until it is first inserted into.

pub fn inner(&self) -> &HashMap<String, Box<dyn Any + Send + Sync>>

Get reference to the depot’s inner map of string-keyed values.

Note: this exposes only values inserted with an explicit string key; values stored by type (via Depot::insert_typed) are kept in separate storage and are not included.

pub fn with_capacity(capacity: usize) -> Self

Creates an empty Depot with the specified capacity for string-keyed values.

The depot will be able to hold at least capacity string-keyed elements without reallocating. If capacity is 0, the depot will not allocate.

pub fn capacity(&self) -> usize

Returns the number of string-keyed elements the depot can hold without reallocating.

pub fn insert_typed<V: Any + Send + Sync>(&mut self, value: V) -> &mut Self

Store a value in the depot, keyed by its type.

pub fn inject<V: Any + Send + Sync>(&mut self, value: V) -> &mut Self

👎Deprecated since 0.94.0:

use Depot::insert_typed instead

Deprecated alias for Depot::insert_typed.

pub fn get_typed<T: Any + Send + Sync>( &self, ) -> Result<&T, Option<&Box<dyn Any + Send + Sync>>>

Get a reference to the value of the given type, previously stored by type.

Returns Err(None) if the value is not present in the depot. Returns Err(Some(Box<dyn Any + Send + Sync>)) if the value is present but downcasting failed.

pub fn obtain<T: Any + Send + Sync>( &self, ) -> Result<&T, Option<&Box<dyn Any + Send + Sync>>>

👎Deprecated since 0.94.0:

use Depot::get_typed instead

Deprecated alias for Depot::get_typed.

pub fn get_typed_mut<T: Any + Send + Sync>( &mut self, ) -> Result<&mut T, Option<&mut Box<dyn Any + Send + Sync>>>

Get a mutable reference to the value of the given type, previously stored by type.

Returns Err(None) if value is not present in depot. Returns Err(Some(Box<dyn Any + Send + Sync>)) if value is present in depot but downcasting failed.

pub fn obtain_mut<T: Any + Send + Sync>( &mut self, ) -> Result<&mut T, Option<&mut Box<dyn Any + Send + Sync>>>

👎Deprecated since 0.94.0:

use Depot::get_typed_mut instead

Deprecated alias for Depot::get_typed_mut.

pub fn insert<K, V>(&mut self, key: K, value: V) -> &mut Self

where K: Into<String>, V: Any + Send + Sync,

Inserts a key-value pair into the depot.

pub fn contains_key(&self, key: &str) -> bool

Check whether a value is stored in the depot under the given key.

pub fn contains_typed<T: Any + Send + Sync>(&self) -> bool

Check whether a value of the given type has been stored in the depot.

Note: Only checks values inserted via Depot::insert_typed.

pub fn contains<T: Any + Send + Sync>(&self) -> bool

👎Deprecated since 0.94.0:

use Depot::contains_typed instead

Deprecated alias for Depot::contains_typed.

pub fn get<V: Any + Send + Sync>( &self, key: &str, ) -> Result<&V, Option<&Box<dyn Any + Send + Sync>>>

Immutably borrows value from depot.

Returns Err(None) if value is not present in depot. Returns Err(Some(Box<dyn Any + Send + Sync>)) if value is present in depot but downcasting failed.

pub fn get_mut<V: Any + Send + Sync>( &mut self, key: &str, ) -> Result<&mut V, Option<&mut Box<dyn Any + Send + Sync>>>

Mutably borrows value from depot.

Returns Err(None) if value is not present in depot. Returns Err(Some(Box<dyn Any + Send + Sync>)) if value is present in depot but downcasting failed.

pub fn remove(&mut self, key: &str) -> Option<Box<dyn Any + Send + Sync>>

Remove the value at the given key from the depot and return it, if present.

The value is returned in its type-erased box; downcast it with Box::downcast if you need the concrete type back. Returns None if the key was not present.

pub fn delete(&mut self, key: &str) -> bool

👎Deprecated since 0.94.0:

use Depot::remove and check the returned Option

Deprecated: use Depot::remove and check the Option (e.g. remove(key).is_some()).

pub fn remove_typed<T: Any + Send + Sync>( &mut self, ) -> Result<T, Option<Box<dyn Any + Send + Sync>>>

Remove the value of the given type from the depot and return it, if present.

Returns Err(None) if value is not present in depot. Returns Err(Some(Box<dyn Any + Send + Sync>)) if value is present in depot but downcasting failed.

pub fn scrape<T: Any + Send + Sync>( &mut self, ) -> Result<T, Option<Box<dyn Any + Send + Sync>>>

👎Deprecated since 0.94.0:

use Depot::remove_typed instead

Deprecated alias for Depot::remove_typed.

Trait Implementations

impl Debug for Depot

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Depot

fn default() -> Depot

Returns the “default value” for a type.