package udpr

import (
    "sync"
)

type ackManager struct {
    mu   sync.Mutex
    acks map[uint32]struct{}
}

func newAckManager() *ackManager {
    return &ackManager{
        acks: make(map[uint32]struct{}),
    }
}

func (am *ackManager) setPending(k uint32) {
    am.mu.Lock()
    defer am.mu.Unlock()
    am.acks[k] = struct{}{}
}

func (am *ackManager) isPending(k uint32) bool {
    am.mu.Lock()
    defer am.mu.Unlock()
    _, ok := am.acks[k]
    return ok
}

func (am *ackManager) clearPending(k uint32) {
    am.mu.Lock()
    defer am.mu.Unlock()
    delete(am.acks, k)
}