Trait casper_execution_engine::storage::global_state::StateReader

pub trait StateReader<K, V> {
    type Error;

    // Required methods
    fn read(
        &self,
        correlation_id: CorrelationId,
        key: &K
    ) -> Result<Option<V>, Self::Error>;
    fn read_with_proof(
        &self,
        correlation_id: CorrelationId,
        key: &K
    ) -> Result<Option<TrieMerkleProof<K, V>>, Self::Error>;
    fn keys_with_prefix(
        &self,
        correlation_id: CorrelationId,
        prefix: &[u8]
    ) -> Result<Vec<K>, Self::Error>;
}

A trait expressing the reading of state. This trait is used to abstract the underlying store.

Required Associated Types

type Error

An error which occurs when reading state

Required Methods

fn read( &self, correlation_id: CorrelationId, key: &K ) -> Result<Option<V>, Self::Error>

Returns the state value from the corresponding key

fn read_with_proof( &self, correlation_id: CorrelationId, key: &K ) -> Result<Option<TrieMerkleProof<K, V>>, Self::Error>

Returns the merkle proof of the state value from the corresponding key

fn keys_with_prefix( &self, correlation_id: CorrelationId, prefix: &[u8] ) -> Result<Vec<K>, Self::Error>

Returns the keys in the trie matching prefix.

Implementors

impl StateReader<Key, StoredValue> for InMemoryGlobalStateView

type Error = Error

impl StateReader<Key, StoredValue> for LmdbGlobalStateView

type Error = Error

impl StateReader<Key, StoredValue> for ScratchGlobalStateView

type Error = Error

impl<R: StateReader<Key, StoredValue>> StateReader<Key, StoredValue> for &TrackingCopy<R>

The purpose of this implementation is to allow a “snapshot” mechanism for TrackingCopy. The state of a TrackingCopy (including the effects of any transforms it has accumulated) can be read using an immutable reference to that TrackingCopy via this trait implementation. See TrackingCopy::fork for more information.

type Error = <R as StateReader<Key, StoredValue>>::Error