Struct SackScoreboard 

pub struct SackScoreboard { /* private fields */ }

Tracks selectively acknowledged ranges for a TCP connection.

Maintains a sorted, non-overlapping list of SACK blocks representing data the remote receiver has confirmed receiving out of order.

Implementations

impl SackScoreboard

pub fn new() -> Self

Create an empty scoreboard.

pub fn block_count(&self) -> usize

Returns the number of tracked SACK blocks.

pub fn blocks(&self) -> &[SackBlock]

Returns a slice of all current SACK blocks.

pub fn is_sacked(&self, seq: u32) -> bool

Returns true if the given sequence number falls within a SACKed range.

pub fn mark_sacked(&mut self, left: u32, right: u32)

Mark a range [left, right) as selectively acknowledged.

Merges with any overlapping or adjacent existing blocks to maintain the invariant that blocks are sorted and non-overlapping.

pub fn clear_below(&mut self, ack: u32)

Remove all blocks (or portions) below the cumulative ACK.

Data below ack has been cumulatively acknowledged, so SACK blocks covering that range are no longer needed.

pub fn highest_sacked(&self) -> Option<u32>

Returns the highest SACKed sequence number, or None if empty.

pub fn next_retransmit(&self, snd_una: u32) -> Option<(u32, u32)>

Returns the next hole (gap) that needs retransmission.

Starting from snd_una (send unacknowledged), finds the first gap between SACK blocks. Returns (start_seq, length) of the hole.

pub fn holes(&self, snd_una: u32) -> Vec<(u32, u32)>

Returns all holes (gaps) between snd_una and the highest SACKed byte.

Each hole is represented as (start_seq, length).

Trait Implementations

impl Default for SackScoreboard

Available on crate feature alloc only.

fn default() -> Self

Returns the “default value” for a type.