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", so this trait is not object safe.

Implementors

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

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