Trait Backend

pub trait Backend<K> {
    // Required methods
    fn save<F: Format, T: Serialize + ConditionalSend + Sync>(
        &self,
        key: K,
        value: &T,
    ) -> impl ConditionalSendFuture<Output = Result<(), Error>>;
    fn load<F: Format, S: for<'de> DeserializeSeed<'de, Value = T> + ConditionalSend, T>(
        &self,
        key: K,
        seed: S,
    ) -> impl ConditionalSendFuture<Output = Result<T, Error>>;
}

Interface between the Format and the disk or other storage.

Implementation

The preferred style for implementing this method is an async fn returning a result.

impl<K: Send> Backend<K> for ExampleBackend {
    async fn save<F: Format, T: Serialize + ConditionalSend + Sync>(
        &self,
        key: K,
        value: &T
    ) -> Result<(), Error> {
        // ...
    }

    async fn load<F: Format, S: for<'de> DeserializeSeed<'de, Value = T> + ConditionalSend, T>(
        &self,
        key: K,
        seed: S,
    ) -> Result<T, Error> {
        // ...
    }
}

Required Methods

fn save<F: Format, T: Serialize + ConditionalSend + Sync>( &self, key: K, value: &T, ) -> impl ConditionalSendFuture<Output = Result<(), Error>>

Attempts to serialize a value with the given Format.

Errors

• Error::Saving if serialization of the type fails
• Error::IO if there is an IO or filesystem failure
• See Error

fn load<F: Format, S: for<'de> DeserializeSeed<'de, Value = T> + ConditionalSend, T>( &self, key: K, seed: S, ) -> impl ConditionalSendFuture<Output = Result<T, Error>>

Attempts to deserialize a value with the given Format.

Errors

• Error::Loading if deserialization of the type fails
• Error::IO if there is an IO or filesystem failure
• See Error

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<K: Display + Send> Backend<K> for FileIO

Available on non-WebAssembly only.