Struct substrate_frame_rpc_support::StorageQuery

pub struct StorageQuery<V> { /* fields omitted */ }

A typed query on chain state usable from an RPC client.

pub type Loc = (i64, i64, i64);
pub type Block = u8;

// Note that all fields are marked pub.
decl_storage! {
    trait Store for Module<T: Config> as TestRuntime {
        pub LastActionId: u64;
        pub Voxels: map hasher(blake2_128_concat) Loc => Block;
        pub Actions: map hasher(blake2_128_concat) u64 => Loc;
        pub Prefab: double_map hasher(blake2_128_concat) u128, hasher(blake2_128_concat) (i8, i8, i8) => Block;
    }
}

let conn = http::connect("http://[::1]:9933").compat().await?;
let cl = StateClient::<Hash>::new(conn);

let q = StorageQuery::value::<LastActionId>();
let _: Option<u64> = q.get(&cl, None).await?;

let q = StorageQuery::map::<Voxels, _>((0, 0, 0));
let _: Option<Block> = q.get(&cl, None).await?;

let q = StorageQuery::map::<Actions, _>(12);
let _: Option<Loc> = q.get(&cl, None).await?;

let q = StorageQuery::double_map::<Prefab, _, _>(3, (0, 0, 0));
let _: Option<Block> = q.get(&cl, None).await?;

Implementations

impl<V: FullCodec> StorageQuery<V>

pub fn value<St: StorageValue<V>>() -> Self

Create a storage query for a StorageValue.

pub fn map<St: StorageMap<K, V>, K: FullEncode>(key: K) -> Self

Create a storage query for a value in a StorageMap.

pub fn double_map<St: StorageDoubleMap<K1, K2, V>, K1: FullEncode, K2: FullEncode>(
    key1: K1,
    key2: K2
) -> Self

Create a storage query for a value in a StorageDoubleMap.

pub async fn get<Hash: Send + Sync + 'static + DeserializeOwned + Serialize>(
    self,
    state_client: &StateClient<Hash>,
    block_index: Option<Hash>
) -> Result<Option<V>, RpcError>

Send this query over RPC, await the typed result.

Hash should be ::Hash.

Arguments

state_client represents a connection to the RPC server.

block_index indicates the block for which state will be queried. A value of None indicates the latest block.

Trait Implementations

impl<V: Clone> Clone for StorageQuery<V>

fn clone(&self) -> StorageQuery<V>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<V: Debug> Debug for StorageQuery<V>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<V: Hash> Hash for StorageQuery<V>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<V: Ord> Ord for StorageQuery<V>

fn cmp(&self, other: &StorageQuery<V>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<V: PartialEq> PartialEq<StorageQuery<V>> for StorageQuery<V>

fn eq(&self, other: &StorageQuery<V>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &StorageQuery<V>) -> bool

This method tests for !=.

impl<V: PartialOrd> PartialOrd<StorageQuery<V>> for StorageQuery<V>

fn partial_cmp(&self, other: &StorageQuery<V>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<V: Eq> Eq for StorageQuery<V>

impl<V> StructuralEq for StorageQuery<V>

impl<V> StructuralPartialEq for StorageQuery<V>