Enum ShardMessage 

pub enum ShardMessage {
    Single {
        request: ShardRequest,
        reply: Sender<ShardResponse>,
    },
    SingleReusable {
        request: ShardRequest,
        reply: Sender<ShardResponse>,
    },
    Batch(Vec<(ShardRequest, Sender<ShardResponse>)>),
}

A request (or batch of requests) bundled with reply channels.

The Batch variant reduces channel traffic during pipelining: instead of N individual sends (one per pipelined command), the connection handler groups commands by target shard and sends one Batch message per shard. This cuts channel contention from O(pipeline_depth) to O(shard_count).

The SingleReusable variant avoids per-command oneshot::channel() allocation on the P=1 (no pipeline) path. The connection handler keeps a long-lived mpsc::channel(1) and reuses it across commands.

Variants

Single

A single request with its reply channel.

Fields

request: ShardRequest

reply: Sender<ShardResponse>

SingleReusable

A single request using a reusable mpsc reply channel.

Avoids the heap allocation of oneshot::channel() on every command. Used for the P=1 fast path where the connection handler sends one command at a time and waits for the response before sending the next.

Fields

request: ShardRequest

reply: Sender<ShardResponse>

Batch(Vec<(ShardRequest, Sender<ShardResponse>)>)

Multiple requests batched for a single channel send.

Trait Implementations

impl Debug for ShardMessage

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

Formats the value using the given formatter.