Struct NetworkQoSManager 

pub struct NetworkQoSManager {
    pub config: QoSConfig,
    pub queues: HashMap<u8, VecDeque<QoSPacket>>,
    pub metrics: HashMap<u8, QueueMetrics>,
    pub violations: VecDeque<SLAViolation>,
    pub total_enqueued: u64,
    pub total_dequeued: u64,
    pub total_dropped: u64,
    /* private fields */
}

Quality-of-Service manager: priority queuing, SLA enforcement, and bandwidth-share scheduling for the IPFRS network layer.

Fields

config: QoSConfig

User-supplied configuration.

queues: HashMap<u8, VecDeque<QoSPacket>>

Priority queues keyed by TrafficClass::priority() (1..=4).

metrics: HashMap<u8, QueueMetrics>

Per-priority queue metrics keyed by priority (1..=4).

violations: VecDeque<SLAViolation>

Bounded log of observed SLA violations (max 1 000 entries).

total_enqueued: u64

Lifetime counter of successfully enqueued packets.

total_dequeued: u64

Lifetime counter of successfully dequeued packets.

total_dropped: u64

Lifetime counter of dropped packets.

Implementations

impl NetworkQoSManager

pub fn new(config: QoSConfig) -> Self

Create a new manager with the given configuration.

Initialises four priority queues (keyed 1..=4) and pre-fills WRR quanta proportional to each class’s bandwidth_share.

pub fn enqueue(&mut self, packet: QoSPacket, _now: u64) -> bool

Enqueue a packet into the priority queue determined by its class.

If the total queue occupancy is at or above max_queue_size:

1. Try to drop the oldest Background packet (priority 1).
2. If Background is already empty, drop the newest Background packet (i.e. the one just being enqueued is discarded instead).
3. If neither relieves enough space, return false.

Returns true when the packet was successfully enqueued.

pub fn drop_packet(&mut self, priority: u8) -> bool

Drop the oldest packet from the queue at priority.

Returns true if a packet was removed, false if the queue was empty.

pub fn dequeue(&mut self, now: u64) -> Option<QoSPacket>

Dequeue the next packet according to the configured scheduling policy.

• Strict priority (enable_strict_priority = true): always pick from the highest non-empty priority queue.
• Weighted round-robin (enable_strict_priority = false): iterate round-robin through classes; add quantum credits each visit and dequeue when credits ≥ packet size. Falls back to the highest non-empty queue if no class accumulates enough credits.

Returns None if all queues are empty.

pub fn check_sla(&mut self, now: u64) -> Vec<SLAViolation>

Check every configured SLA spec against current queue metrics.

Any violation is appended to the internal violations log (bounded to 1 000 entries, oldest evicted on overflow). The set of violations discovered during this call is returned.

pub fn queue_metrics(&self, class: &TrafficClass) -> Option<&QueueMetrics>

Return queue metrics for a specific traffic class, or None if the class is not tracked (should not happen with a correctly initialised manager).

pub fn all_metrics(&self) -> Vec<&QueueMetrics>

Return metrics for all four priority queues ordered highest-first.

pub fn total_queued_bytes(&self) -> usize

Total byte count across all queued packets.

pub fn violations_log(&self) -> &VecDeque<SLAViolation>

Immutable reference to the bounded violations log.

pub fn qos_stats(&self) -> QoSStats

Aggregate statistics snapshot.

pub fn reset_metrics(&mut self)

Reset all per-class EWMA wait metrics to zero (useful for test isolation or after a reconfiguration event).

pub fn flush_all(&mut self) -> usize

Drain all packets from all queues and return the total count removed.