Trait StorageMap 

pub trait StorageMap {
    type KEY: Decode + Encode;
    type VALUE: Decode;

    const PALLET_NAME: &'static str;
    const STORAGE_NAME: &'static str;
    const KEY_HASHER: StorageHasher;

    // Provided methods
    fn encode_partial_key() -> [u8; 32] { ... }
    fn hex_encode_partial_key() -> String { ... }
    fn encode_storage_key(key: &Self::KEY) -> Vec<u8>  { ... }
    fn hex_encode_storage_key(key: &Self::KEY) -> String { ... }
    fn decode_hex_storage_key(value: &str) -> Result<Self::KEY, Error> { ... }
    fn decode_storage_key(value: &mut &[u8]) -> Result<Self::KEY, Error> { ... }
    fn decode_hex_storage_value(value: &str) -> Result<Self::VALUE, Error> { ... }
    fn decode_storage_value(value: &mut &[u8]) -> Result<Self::VALUE, Error> { ... }
    fn fetch(
        client: &RpcClient,
        key: &Self::KEY,
        at: Option<H256>,
    ) -> impl Future<Output = Result<Option<Self::VALUE>, Error>> { ... }
    fn iter(client: RpcClient, block_hash: H256) -> StorageMapIterator<Self>
       where Self: Sized { ... }
}

Required Associated Constants

const PALLET_NAME: &'static str

const STORAGE_NAME: &'static str

const KEY_HASHER: StorageHasher

Required Associated Types

type KEY: Decode + Encode

type VALUE: Decode

Provided Methods

fn encode_partial_key() -> [u8; 32]

fn hex_encode_partial_key() -> String

fn encode_storage_key(key: &Self::KEY) -> Vec<u8>

fn hex_encode_storage_key(key: &Self::KEY) -> String

fn decode_hex_storage_key(value: &str) -> Result<Self::KEY, Error>

Decodes the Hex and SCALE encoded Storage Key This is equal to Hex::decode + Self::decode_storage_key

If you need to decode bytes call decode_storage_key

fn decode_storage_key(value: &mut &[u8]) -> Result<Self::KEY, Error>

Decodes the SCALE encoded Storage Key

If you need to decode Hex string call decode_hex_storage_key

fn decode_hex_storage_value(value: &str) -> Result<Self::VALUE, Error>

Decodes the Hex and SCALE encoded Storage Value This is equal to Hex::decode + Self::decode_storage_value

If you need to decode bytes call decode_storage_value

fn decode_storage_value(value: &mut &[u8]) -> Result<Self::VALUE, Error>

Decodes the SCALE encoded Storage Value

If you need to decode Hex string call decode_hex_storage_value

fn fetch( client: &RpcClient, key: &Self::KEY, at: Option<H256>, ) -> impl Future<Output = Result<Option<Self::VALUE>, Error>>

Fetches and decodes a Storage Value

Returns None if no Storage Value is present

fn iter(client: RpcClient, block_hash: H256) -> StorageMapIterator<Self>

where Self: Sized,

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl StorageMap for Account

const KEY_HASHER: StorageHasher = StorageHasher::Blake2_128Concat

const PALLET_NAME: &'static str = "System"

const STORAGE_NAME: &'static str = "Account"

type KEY = AccountId32

type VALUE = AccountInfo

impl StorageMap for AppKeys

const KEY_HASHER: StorageHasher = StorageHasher::Blake2_128Concat

const PALLET_NAME: &'static str = "DataAvailability"

const STORAGE_NAME: &'static str = "AppKeys"

type KEY = Vec<u8>

type VALUE = AppKey

impl StorageMap for SetIdSession

const KEY_HASHER: StorageHasher = StorageHasher::Twox64Concat

const PALLET_NAME: &'static str = "Grandpa"

const STORAGE_NAME: &'static str = "SetIdSession"

type KEY = u64

type VALUE = u32