blob: ebd7483659727f432f7c0d54a6e01176ee0d78af [file] [log] [blame]
// 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.
#include "quic/core/quic_datagram_queue.h"
#include "absl/types/span.h"
#include "quic/core/quic_constants.h"
#include "quic/core/quic_session.h"
#include "quic/core/quic_time.h"
#include "quic/core/quic_types.h"
namespace quic {
constexpr float kExpiryInMinRtts = 1.25;
constexpr float kMinPacingWindows = 4;
QuicDatagramQueue::QuicDatagramQueue(QuicSession* session)
: QuicDatagramQueue(session, nullptr) {}
QuicDatagramQueue::QuicDatagramQueue(QuicSession* session,
std::unique_ptr<Observer> observer)
: session_(session),
clock_(session->connection()->clock()),
observer_(std::move(observer)) {}
MessageStatus QuicDatagramQueue::SendOrQueueDatagram(QuicMemSlice datagram) {
// If the queue is non-empty, always queue the daragram. This ensures that
// the datagrams are sent in the same order that they were sent by the
// application.
if (queue_.empty()) {
MessageResult result = session_->SendMessage(absl::MakeSpan(&datagram, 1));
if (result.status != MESSAGE_STATUS_BLOCKED) {
if (observer_) {
observer_->OnDatagramProcessed(result.status);
}
return result.status;
}
}
queue_.emplace_back(Datagram{std::move(datagram),
clock_->ApproximateNow() + GetMaxTimeInQueue()});
return MESSAGE_STATUS_BLOCKED;
}
absl::optional<MessageStatus> QuicDatagramQueue::TrySendingNextDatagram() {
RemoveExpiredDatagrams();
if (queue_.empty()) {
return absl::nullopt;
}
MessageResult result =
session_->SendMessage(absl::MakeSpan(&queue_.front().datagram, 1));
if (result.status != MESSAGE_STATUS_BLOCKED) {
queue_.pop_front();
if (observer_) {
observer_->OnDatagramProcessed(result.status);
}
}
return result.status;
}
size_t QuicDatagramQueue::SendDatagrams() {
size_t num_datagrams = 0;
for (;;) {
absl::optional<MessageStatus> status = TrySendingNextDatagram();
if (!status.has_value()) {
break;
}
if (*status == MESSAGE_STATUS_BLOCKED) {
break;
}
num_datagrams++;
}
return num_datagrams;
}
QuicTime::Delta QuicDatagramQueue::GetMaxTimeInQueue() const {
if (!max_time_in_queue_.IsZero()) {
return max_time_in_queue_;
}
const QuicTime::Delta min_rtt =
session_->connection()->sent_packet_manager().GetRttStats()->min_rtt();
return std::max(kExpiryInMinRtts * min_rtt,
kMinPacingWindows * kAlarmGranularity);
}
void QuicDatagramQueue::RemoveExpiredDatagrams() {
QuicTime now = clock_->ApproximateNow();
while (!queue_.empty() && queue_.front().expiry <= now) {
queue_.pop_front();
if (observer_) {
observer_->OnDatagramProcessed(absl::nullopt);
}
}
}
} // namespace quic