Struct RequestCorrelator 

pub struct RequestCorrelator<K: Copy, const N: usize> { /* private fields */ }

A fixed table of the requests a client has in flight, each keyed by the sequence id the backend assigned and carrying a caller-chosen K (() for a plain service client, the GoalUuid for an action sub-client).

See the module docs for the rule it applies.

Implementations

impl<K: Copy + Default, const N: usize> RequestCorrelator<K, N>

pub fn new() -> Self

An empty table.

impl<K: Copy, const N: usize> RequestCorrelator<K, N>

pub const CAPACITY: usize = N

The table’s capacity.

pub fn len(&self) -> usize

Requests currently pending.

pub fn is_empty(&self) -> bool

No request pending.

pub fn dropped(&self) -> u32

Replies dropped so far because no pending request matched them.

pub fn can_send(&self) -> Result<(), SendRefusal>

Whether a new request may be SENT now. Ask this before the send, so a refused request never reaches the wire.

pub fn contains(&self, seq: i64) -> bool

Whether seq is pending.

pub fn insert(&mut self, seq: i64, key: K) -> Result<(), SendRefusal>

Record a request the backend accepted. Call after a send can_send allowed; Err(Full) if the table is full anyway (nothing is recorded then).

pub fn insert_evicting(&mut self, seq: i64, key: K)

Record a request, evicting the OLDEST pending one when the table is full. For a RE-SEND of one logical call (rclc_client_call’s discovery-race retry), where every generation answers the same question and the oldest is the least likely to still be answered.

pub fn remove(&mut self, seq: i64) -> bool

Forget a pending request (cancelled / removed). Its reply, if it still comes, is dropped. true if it was pending.

pub fn remove_key(&mut self, key: &K) -> bool

where K: PartialEq,

Forget ONE pending request carrying key — the oldest — as remove does by id. For a caller that knows what a request was ABOUT but not the id the backend gave it: an action client’s future is keyed by its goal, so when the last owner of a goal’s request lets go before the reply, this frees the slot the request held (issue 2027). Its reply, if it still comes, is dropped. true if one was pending.

pub fn clear(&mut self)

Forget every pending request (the caller abandoned them all — a timed-out blocking call, reset_in_flight). Their replies are dropped.

pub fn resolve(&mut self, reply_seq: i64) -> Option<K>

Match a reply carrying reply_seq to a pending request. Some(key) removes and returns the request it answers; None means the reply is STALE and the caller drops it.

Trait Implementations

impl<K: Clone + Copy, const N: usize> Clone for RequestCorrelator<K, N>

fn clone(&self) -> RequestCorrelator<K, N>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<K: Copy + Copy, const N: usize> Copy for RequestCorrelator<K, N>

impl<K: Debug + Copy, const N: usize> Debug for RequestCorrelator<K, N>

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

Formats the value using the given formatter.

impl<K: Copy + Default, const N: usize> Default for RequestCorrelator<K, N>

fn default() -> Self

Returns the “default value” for a type.

impl<K: Copy, const N: usize> ReplyMatcher for RequestCorrelator<K, N>

fn match_reply(&mut self, reply_seq: i64) -> bool

true if reply_seq answers a pending request (which is then retired), false if the reply is stale and must be dropped.