Struct PreserveShard

pub struct PreserveShard<P: Plan + Shardable> {
    pub inner: P,
    pub shard: Option<P::Shard>,
}

When executed, the plan clones the shard and execute its inner plan, then returns (shard, response).

It’s useful when the information of shard are lost in the response but needed for processing.

Fields

inner: P

shard: Option<P::Shard>

Trait Implementations

impl<P: Plan + Shardable> Clone for PreserveShard<P>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<P> Plan for PreserveShard<P>

where P: Plan + Shardable,

type Result = ResponseWithShard<<P as Plan>::Result, <P as Shardable>::Shard>

The ultimate result of executing the plan (should be a high-level type, not a GRPC response).

fn execute<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Self::Result>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Execute the plan.

impl<P: Plan + Shardable> Shardable for PreserveShard<P>

type Shard = <P as Shardable>::Shard

fn shards( &self, pd_client: &Arc<impl PdClient>, ) -> BoxStream<'static, Result<(Self::Shard, RegionStore)>>

fn apply_shard(&mut self, shard: Self::Shard, store: &RegionStore) -> Result<()>