sp_runtime::offchain

Trait OffchainStorage

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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;
}
Expand description

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

Required Methods§

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

Persist a value in storage under given key and prefix.

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

Clear a storage entry under given key and prefix.

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

Retrieve a value from storage under given key and prefix.

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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.

Object Safety§

This trait is not object safe.

Implementors§