Trait OffchainStorage

pub trait OffchainStorage:
    Clone
    + Send
    + Sync {
    // Required methods
    fn set(&mut self, prefix: &[u8], key: &[u8], value: &[u8]);
    fn remove(&mut self, prefix: &[u8], key: &[u8]);
    fn get(&self, prefix: &[u8], key: &[u8]) -> Option<Vec<u8>>;
    fn compare_and_set(
        &mut self,
        prefix: &[u8],
        key: &[u8],
        old_value: Option<&[u8]>,
        new_value: &[u8],
    ) -> bool;
}

Offchain DB persistent (non-fork-aware) storage.

Required Methods

fn set(&mut self, prefix: &[u8], key: &[u8], value: &[u8])

Persist a value in storage under given key and prefix.

fn remove(&mut self, prefix: &[u8], key: &[u8])

Clear a storage entry under given key and prefix.

fn get(&self, prefix: &[u8], key: &[u8]) -> Option<Vec<u8>>

Retrieve a value from storage under given key and prefix.

fn compare_and_set( &mut self, prefix: &[u8], key: &[u8], old_value: Option<&[u8]>, new_value: &[u8], ) -> bool

Replace the value in storage if given old_value matches the current one.

Returns true if the value has been set and false otherwise.

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 OffchainStorage for TestPersistentOffchainDB

impl OffchainStorage for InMemOffchainStorage

impl OffchainStorage for LocalStorage

impl OffchainStorage for NoOffchainStorage