Struct substrate_frame_rpc_support::StorageQuery

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

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.
pub use self::pallet_test::*;

#[frame_support::pallet]
mod pallet_test {
	use super::*;
	use frame_support::pallet_prelude::*;

	#[pallet::pallet]
	pub struct Pallet<T>(_);

	#[pallet::config]
	pub trait Config: frame_system::Config {}

	#[pallet::storage]
	pub type LastActionId<T> = StorageValue<_, u64, ValueQuery>;

	#[pallet::storage]
	pub type Voxels<T> = StorageMap<_, Blake2_128Concat, Loc, Block>;

	#[pallet::storage]
	pub type Actions<T> = StorageMap<_, Blake2_128Concat, u64, Loc>;

	#[pallet::storage]
	pub type Prefab<T> = StorageDoubleMap<
		_,
		Blake2_128Concat, u128,
		Blake2_128Concat, (i8, i8, i8), Block
	>;
}

#[tokio::main]
async fn main() -> Result<(), RpcError> {
    let cl = WsClientBuilder::default().build("ws://[::1]:9944").await?;

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

    let q = StorageQuery::map::<Voxels<TestRuntime>, _>((0, 0, 0));
    let _: Option<Block> = q.get(&cl, hash).await?;

    let q = StorageQuery::map::<Actions<TestRuntime>, _>(12);
    let _: Option<Loc> = q.get(&cl, hash).await?;

    let q = StorageQuery::double_map::<Prefab<TestRuntime>, _, _>(3, (0, 0, 0));
    let _: Option<Block> = q.get(&cl, hash).await?;

    Ok(())
}

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, StateClient>( self, state_client: &StateClient, block_index: Option<Hash>, ) -> Result<Option<V>, RpcError>

where Hash: Send + Sync + 'static + DeserializeOwned + Serialize, StateClient: StateApiClient<Hash> + Sync,

Send this query over RPC, await the typed result.

Hash should be <YourRuntime as frame_system::Config>::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, Self: Sized,

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<V: PartialEq> PartialEq 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: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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