Struct KBucket 

pub struct KBucket {
    pub entries: Vec<BucketEntry>,
    pub replacement_cache: VecDeque<BucketEntry>,
    pub max_size: usize,
}

A single Kademlia k-bucket.

Entries are stored in LRU order: index 0 is the least-recently-seen node, index len-1 is the most-recently-seen node. When the bucket is full a newly observed node goes into replacement_cache rather than the bucket.

Fields

entries: Vec<BucketEntry>

Active entries, ordered from least-recently-seen (front) to most-recently-seen (back).

replacement_cache: VecDeque<BucketEntry>

Candidates waiting to replace evicted entries (FIFO).

max_size: usize

Maximum number of active entries.

Implementations

impl KBucket

pub fn new(max_size: usize) -> Self

Create an empty k-bucket with the given maximum size.

pub fn is_empty(&self) -> bool

Returns true if the bucket holds no active entries.

pub fn len(&self) -> usize

Returns the number of active entries.

pub fn is_full(&self) -> bool

Returns true if the active-entry list is at capacity.

pub fn add(&mut self, entry: BucketEntry)

Insert or refresh a node in the bucket.

• If the node already exists in active entries → move to tail (LRU update).
• Else if the bucket is not full → append to tail.
• Else if the node is in the replacement cache → update it there.
• Else → push to the back of the replacement cache (bounded by DEFAULT_REPLACEMENT_CACHE_SIZE).

pub fn remove(&mut self, node_id: &NodeId) -> bool

Remove the node with the given ID from active entries.

If a replacement candidate exists in the cache it is promoted.

Returns true if the node was found and removed.

pub fn mark_failed(&mut self, node_id: &NodeId, now: u64) -> bool

Increment the failure counter for a node.

Returns true if the node was evicted due to too many failures.

pub fn update_rtt(&mut self, node_id: &NodeId, rtt_ms: u64, now: u64)

Update the RTT and last-seen timestamp for a node.

Trait Implementations

impl Clone for KBucket

fn clone(&self) -> KBucket

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KBucket

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

Formats the value using the given formatter.