| // Copyright 2019 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef QUICHE_QUIC_CORE_QUIC_DATAGRAM_QUEUE_H_ |
| #define QUICHE_QUIC_CORE_QUIC_DATAGRAM_QUEUE_H_ |
| |
| #include <memory> |
| |
| #include "absl/types/optional.h" |
| #include "quic/core/quic_time.h" |
| #include "quic/core/quic_types.h" |
| #include "quic/platform/api/quic_mem_slice.h" |
| #include "common/quiche_circular_deque.h" |
| |
| namespace quic { |
| |
| class QuicSession; |
| |
| // Provides a way to buffer QUIC datagrams (messages) in case they cannot |
| // be sent due to congestion control. Datagrams are buffered for a limited |
| // amount of time, and deleted after that time passes. |
| class QUIC_EXPORT_PRIVATE QuicDatagramQueue { |
| public: |
| // An interface used to monitor events on the associated `QuicDatagramQueue`. |
| class QUIC_EXPORT_PRIVATE Observer { |
| public: |
| virtual ~Observer() = default; |
| |
| // Called when a datagram in the associated queue is sent or discarded. |
| // Identity information for the datagram is not given, because the sending |
| // and discarding order is always first-in-first-out. |
| // This function is called synchronously in `QuicDatagramQueue` methods. |
| // `status` is nullopt when the datagram is dropped due to being in the |
| // queue for too long. |
| virtual void OnDatagramProcessed(absl::optional<MessageStatus> status) = 0; |
| }; |
| |
| // |session| is not owned and must outlive this object. |
| explicit QuicDatagramQueue(QuicSession* session); |
| |
| // |session| is not owned and must outlive this object. |
| QuicDatagramQueue(QuicSession* session, std::unique_ptr<Observer> observer); |
| |
| // Adds the datagram to the end of the queue. May send it immediately; if |
| // not, MESSAGE_STATUS_BLOCKED is returned. |
| MessageStatus SendOrQueueDatagram(QuicMemSlice datagram); |
| |
| // Attempts to send a single datagram from the queue. Returns the result of |
| // SendMessage(), or nullopt if there were no unexpired datagrams to send. |
| absl::optional<MessageStatus> TrySendingNextDatagram(); |
| |
| // Sends all of the unexpired datagrams until either the connection becomes |
| // write-blocked or the queue is empty. Returns the number of datagrams sent. |
| size_t SendDatagrams(); |
| |
| // Returns the amount of time a datagram is allowed to be in the queue before |
| // it is dropped. If not set explicitly using SetMaxTimeInQueue(), an |
| // RTT-based heuristic is used. |
| QuicTime::Delta GetMaxTimeInQueue() const; |
| |
| void SetMaxTimeInQueue(QuicTime::Delta max_time_in_queue) { |
| max_time_in_queue_ = max_time_in_queue; |
| } |
| |
| size_t queue_size() { return queue_.size(); } |
| |
| bool empty() { return queue_.empty(); } |
| |
| private: |
| struct QUIC_EXPORT_PRIVATE Datagram { |
| QuicMemSlice datagram; |
| QuicTime expiry; |
| }; |
| |
| // Removes expired datagrams from the front of the queue. |
| void RemoveExpiredDatagrams(); |
| |
| QuicSession* session_; // Not owned. |
| const QuicClock* clock_; |
| |
| QuicTime::Delta max_time_in_queue_ = QuicTime::Delta::Zero(); |
| quiche::QuicheCircularDeque<Datagram> queue_; |
| std::unique_ptr<Observer> observer_; |
| }; |
| |
| } // namespace quic |
| |
| #endif // QUICHE_QUIC_CORE_QUIC_DATAGRAM_QUEUE_H_ |