Struct EndgameState 

pub struct EndgameState { /* private fields */ }

Tracks duplicate requests during endgame mode.

In endgame mode (when <=5 pieces remain incomplete), we request the same block from multiple peers simultaneously to speed up completion. When any peer responds with the block data, we send Cancel messages to the other peers that also received the request for that block.

This struct maintains the mapping from block identifiers to the list of peers that were sent duplicate requests, enabling efficient cancellation on arrival.

Implementations

impl EndgameState

pub fn new() -> Self

Create a new EndgameState in inactive state

pub fn enter_endgame(&mut self)

Enter endgame mode - enables duplicate request tracking

pub fn exit_endgame(&mut self)

Exit endgame mode and clear all tracked requests

pub fn track_request( &mut self, piece: u32, offset: u32, len: u32, peer_id: usize, )

Register that a request was sent to a peer during endgame

This tracks which peers have pending requests for each block so we can cancel redundant requests when the first response arrives.

pub fn get_cancel_targets( &self, piece: u32, offset: u32, len: u32, ) -> Vec<usize>

When a block arrives, find other peers that have pending requests for the same block

Returns the list of peer indices that should receive Cancel messages. Does NOT remove the entry (call remove_request after sending cancels).

pub fn remove_request(&mut self, piece: u32, offset: u32, len: u32)

Remove a tracked request after cancel or completion

Called after Cancel messages have been sent and the block is fully processed.

pub fn is_endgame_active(&self) -> bool

Check if endgame mode is currently active

pub fn tracked_count(&self) -> usize

Get the number of actively tracked duplicate requests (for debugging/metrics)

Trait Implementations

impl Default for EndgameState

fn default() -> Self

Returns the “default value” for a type.