Trait Context

pub trait Context:
    Clone
    + Send
    + Sync
where
    ViewError: From<Self::Error>,
{
    type Store: ReadableKeyValueStore + WritableKeyValueStore + WithError<Error = Self::Error>;
    type Extra: Clone + AutoTraits;
    type Error: KeyValueStoreError;

    // Required methods
    fn store(&self) -> &Self::Store;
    fn extra(&self) -> &Self::Extra;
    fn base_key(&self) -> &BaseKey;
    fn base_key_mut(&mut self) -> &mut BaseKey;

    // Provided methods
    fn clone_with_base_key(&self, base_key: Vec<u8>) -> Self { ... }
    fn clone_with_trimmed_key(&self, n: usize) -> Self { ... }
}

The context in which a view is operated. Typically, this includes the client to connect to the database and the address of the current entry.

Required Associated Types

type Store: ReadableKeyValueStore + WritableKeyValueStore + WithError<Error = Self::Error>

The type of the key-value store used by this context.

type Extra: Clone + AutoTraits

User-provided data to be carried along.

type Error: KeyValueStoreError

The type of errors that may be returned by operations on the Store, a convenience alias for <Self::Store as WithError>::Error.

Required Methods

fn store(&self) -> &Self::Store

Getter for the store.

fn extra(&self) -> &Self::Extra

Getter for the user-provided data.

fn base_key(&self) -> &BaseKey

Getter for the address of the base key.

fn base_key_mut(&mut self) -> &mut BaseKey

Mutable getter for the address of the base key.

Provided Methods

fn clone_with_base_key(&self, base_key: Vec<u8>) -> Self

Obtains a similar Context implementation with a different base key.

fn clone_with_trimmed_key(&self, n: usize) -> Self

Obtains a similar Context implementation with the last n bytes of the base key trimmed.

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 Context for InactiveContext

type Store = InactiveStore

type Extra = ()

type Error = InactiveStoreError

impl<E, S> Context for ViewContext<E, S>

where E: Clone + AutoTraits, S: ReadableKeyValueStore + WritableKeyValueStore + Clone, S::Error: From<Error> + Send + Sync + Error + 'static,

type Extra = E

type Store = S

type Error = <S as WithError>::Error