Struct GhostNodeCache 

pub struct GhostNodeCache { /* private fields */ }

Cache of ghost nodes from other shards.

Ghost nodes are references to nodes that live on remote shards. This cache maintains a bounded set of ghost nodes using LRU eviction to keep frequently accessed nodes available while limiting memory usage.

Example

use phago_distributed::shard::GhostNodeCache;

let mut cache = GhostNodeCache::new(100);
cache.insert(ghost_node);

if let Some(ghost) = cache.get(&node_id) {
    println!("Found ghost node: {}", ghost.label);
}

Implementations

impl GhostNodeCache

pub fn new(max_size: usize) -> Self

Create a new ghost node cache with the specified maximum size.

Arguments

• max_size - Maximum number of ghost nodes to cache

pub fn get(&mut self, id: &NodeId) -> Option<&GhostNode>

Get a ghost node from cache.

Updates the access order for LRU tracking.

Arguments

• id - The node ID to look up

Returns

A reference to the ghost node if found.

pub fn peek(&self, id: &NodeId) -> Option<&GhostNode>

Get a ghost node without updating LRU order (for read-only access).

pub fn insert(&mut self, ghost: GhostNode)

Insert a ghost node into the cache.

If the cache is at capacity, the least recently used node will be evicted to make room.

Arguments

• ghost - The ghost node to insert

pub fn update_full_data(&mut self, id: &NodeId, data: NodeData)

Update a ghost node with full data fetched from the remote shard.

Arguments

• id - The node ID to update
• data - The full node data

pub fn contains(&self, id: &NodeId) -> bool

Check if a node is cached.

Arguments

• id - The node ID to check

pub fn nodes_from_shard(&self, shard_id: ShardId) -> Vec<&GhostNode>

Get all ghost nodes from a specific shard.

Arguments

• shard_id - The shard to filter by

Returns

A vector of references to ghost nodes from the specified shard.

pub fn all_nodes(&self) -> Vec<&GhostNode>

Get all ghost nodes in the cache.

pub fn remove(&mut self, id: &NodeId) -> Option<GhostNode>

Remove a ghost node from the cache.

Arguments

• id - The node ID to remove

Returns

The removed ghost node if it was present.

pub fn clear(&mut self)

Clear the cache.

pub fn len(&self) -> usize

Number of cached nodes.

pub fn is_empty(&self) -> bool

Check if cache is empty.

pub fn capacity(&self) -> usize

Get the maximum cache size.

pub fn invalidate_shard(&mut self, shard_id: ShardId) -> usize

Invalidate all ghost nodes from a specific shard.

This is useful when a shard becomes unavailable or undergoes significant changes.

Arguments

• shard_id - The shard whose nodes should be invalidated

Returns

The number of nodes that were invalidated.

pub fn stats(&self) -> GhostCacheStats

Get statistics about the cache.