Trait StorageMapKeyProvider

pub trait StorageMapKeyProvider {
    type Hasher: StorageHasher;
    type Key: FullCodec + Send + Sync;
    type Value: 'static + FullCodec;

    const MAP_NAME: &'static str;

    // Provided method
    fn final_key(pallet_prefix: &str, key: &Self::Key) -> StorageKey { ... }
}

Can be use to access the runtime storage key of a StorageMap.

Required Associated Constants

const MAP_NAME: &'static str

The name of the variable that holds the StorageMap.

Required Associated Types

type Hasher: StorageHasher

The same as StorageMap::Hasher1.

type Key: FullCodec + Send + Sync

The same as StorageMap::Key1.

type Value: 'static + FullCodec

The same as StorageMap::Value.

Provided Methods

fn final_key(pallet_prefix: &str, key: &Self::Key) -> StorageKey

This is a copy of the frame_support::storage::generator::StorageMap::storage_map_final_key.

We’re using it because to call storage_map_final_key directly, we need access to the runtime and pallet instance, which (sometimes) is impossible.

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 StorageMapKeyProvider for ParasInfoKeyProvider

impl StorageMapKeyProvider for AccountInfoStorageMapKeyProvider