Enum ClusterCommand 

pub enum ClusterCommand {
    DataPut {
        key: Vec<u8>,
        value: Vec<u8>,
    },
    DataDelete {
        key: Vec<u8>,
    },
    PlaceSplit {
        shard_id: ShardId,
        split_key: Vec<u8>,
    },
    PlaceMerge {
        left_shard_id: ShardId,
        right_shard_id: ShardId,
    },
    PlaceTransfer {
        shard_id: ShardId,
        from_node: NodeId,
        to_node: NodeId,
    },
    MembershipAdd {
        node_id: NodeId,
        address: String,
    },
    MembershipRemove {
        node_id: NodeId,
    },
}

A typed, serialisable view over the raw Command::data bytes in a Raft log entry.

Use ClusterCommand::encode to produce bytes suitable for crate::log::Command::new, and ClusterCommand::decode (or the TryFrom<&[u8]> impl) to reconstruct the command on the receiver side.

Variants

DataPut

A KV put (data plane, future use).

Fields

key: Vec<u8>

The key to insert or overwrite.

value: Vec<u8>

The value to associate with the key.

DataDelete

A KV delete (data plane, future use).

Fields

key: Vec<u8>

The key to delete.

PlaceSplit

Split a hot shard at split_key.

Fields

shard_id: ShardId

The shard to split.

split_key: Vec<u8>

The key at which to split, serialised as raw bytes.

PlaceMerge

Merge two adjacent cold shards into one.

Fields

left_shard_id: ShardId

The left (lower-range) shard.

right_shard_id: ShardId

The right (higher-range) shard.

PlaceTransfer

Transfer a shard from one node to another to rebalance load.

Fields

shard_id: ShardId

The shard to move.

from_node: NodeId

The node currently hosting the shard.

to_node: NodeId

The node that should receive the shard.

MembershipAdd

Add a cluster member (membership plane).

Fields

node_id: NodeId

The node ID to admit.

address: String

The network address of the new node.

MembershipRemove

Remove a cluster member (membership plane).

Fields

node_id: NodeId

The node ID to evict.

Implementations

impl ClusterCommand

pub fn tag(&self) -> u8

Return the single-byte tag that identifies this variant.

The tag is stored as the first byte of the encoded form and enables O(1) dispatch without deserialising the JSON payload.

pub fn encode(&self) -> Vec<u8>

Encode the command as [tag_byte][json_bytes].

The result is suitable for use as the data field of a crate::log::Command.

pub fn decode(bytes: &[u8]) -> RaftResult<Self>

Decode a command from [tag_byte][json_bytes].

Returns an error if the byte slice is empty, the tag is unknown, or the JSON body cannot be deserialised.

pub fn from_placement_action(action: &PlacementAction) -> Self

Convert a crate::placement::PlacementAction into the corresponding ClusterCommand.

PlacementAction variant	ClusterCommand variant
Split	PlaceSplit
Merge	PlaceMerge
Transfer	PlaceTransfer

Trait Implementations

impl Clone for ClusterCommand

fn clone(&self) -> ClusterCommand

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClusterCommand

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ClusterCommand

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ClusterCommand

impl PartialEq for ClusterCommand

fn eq(&self, other: &ClusterCommand) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

impl Serialize for ClusterCommand

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ClusterCommand

impl TryFrom<&[u8]> for ClusterCommand

fn try_from(bytes: &[u8]) -> Result<Self, Self::Error>

Delegate to ClusterCommand::decode.

type Error = RaftError

The type returned in the event of a conversion error.