deprecate FLAGS_quic_disable_pre_34

net/quic/core/quic_sent_entropy_manager.cc

-// Copyright 2013 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 "net/quic/core/quic_sent_entropy_manager.h"
-
-#include "base/logging.h"
-#include "net/base/linked_hash_map.h"
-#include "net/quic/core/quic_flags.h"
-
-using std::make_pair;
-using std::max;
-using std::min;
-
-namespace net {
-
-QuicSentEntropyManager::QuicSentEntropyManager() : map_offset_(1) {}
-
-QuicSentEntropyManager::~QuicSentEntropyManager() {}
-
-QuicPacketEntropyHash QuicSentEntropyManager::GetPacketEntropy(
-    QuicPacketNumber packet_number) const {
-  return packets_entropy_[packet_number - map_offset_];
-}
-
-QuicPacketNumber QuicSentEntropyManager::GetLargestPacketWithEntropy() const {
-  return map_offset_ + packets_entropy_.size() - 1;
-}
-
-QuicPacketNumber QuicSentEntropyManager::GetSmallestPacketWithEntropy() const {
-  return map_offset_;
-}
-
-void QuicSentEntropyManager::UpdateCumulativeEntropy(
-    QuicPacketNumber packet_number,
-    CumulativeEntropy* cumulative) const {
-  while (cumulative->packet_number < packet_number) {
-    ++cumulative->packet_number;
-    cumulative->entropy ^= GetPacketEntropy(cumulative->packet_number);
-  }
-}
-
-void QuicSentEntropyManager::RecordPacketEntropyHash(
-    QuicPacketNumber packet_number,
-    QuicPacketEntropyHash entropy_hash) {
-  if (!packets_entropy_.empty()) {
-    // Ensure packets always are recorded in order.
-    // Every packet's entropy is recorded, even if it's not sent, so there
-    // are not packet number gaps.
-    DCHECK_EQ(GetLargestPacketWithEntropy() + 1, packet_number);
-  }
-  packets_entropy_.push_back(entropy_hash);
-  DVLOG(2) << "Recorded packet number " << packet_number
-           << " with entropy hash: " << static_cast<int>(entropy_hash);
-}
-
-QuicPacketEntropyHash QuicSentEntropyManager::GetCumulativeEntropy(
-    QuicPacketNumber packet_number) {
-  DCHECK_LE(last_cumulative_entropy_.packet_number, packet_number);
-  DCHECK_GE(GetLargestPacketWithEntropy(), packet_number);
-  // First the entropy for largest_observed packet number should be updated.
-  UpdateCumulativeEntropy(packet_number, &last_cumulative_entropy_);
-  return last_cumulative_entropy_.entropy;
-}
-
-bool QuicSentEntropyManager::IsValidEntropy(
-    QuicPacketNumber largest_observed,
-    const PacketNumberQueue& missing_packets,
-    QuicPacketEntropyHash entropy_hash) {
-  DCHECK_GE(largest_observed, last_valid_entropy_.packet_number);
-  // Ensure the largest and smallest packet numbers are in range.
-  if (largest_observed > GetLargestPacketWithEntropy()) {
-    return false;
-  }
-  if (!missing_packets.Empty() &&
-      missing_packets.Min() < GetSmallestPacketWithEntropy()) {
-    return false;
-  }
-  // First the entropy for largest_observed packet number should be updated.
-  UpdateCumulativeEntropy(largest_observed, &last_valid_entropy_);
-
-  // Now XOR out all the missing entropies.
-  QuicPacketEntropyHash expected_entropy_hash = last_valid_entropy_.entropy;
-  for (const Interval<QuicPacketNumber>& interval : missing_packets) {
-    for (QuicPacketNumber packet_number = interval.min();
-         packet_number < interval.max(); ++packet_number) {
-      expected_entropy_hash ^= GetPacketEntropy(packet_number);
-    }
-  }
-  DLOG_IF(WARNING, entropy_hash != expected_entropy_hash)
-      << "Invalid entropy hash: " << static_cast<int>(entropy_hash)
-      << " expected entropy hash: " << static_cast<int>(expected_entropy_hash);
-  return entropy_hash == expected_entropy_hash;
-}
-
-void QuicSentEntropyManager::ClearEntropyBefore(
-    QuicPacketNumber packet_number) {
-  // Don't discard entropy before updating the cumulative entropy used to
-  // calculate EntropyHash and IsValidEntropy.
-  if (last_cumulative_entropy_.packet_number < packet_number) {
-    UpdateCumulativeEntropy(packet_number, &last_cumulative_entropy_);
-  }
-  if (last_valid_entropy_.packet_number < packet_number) {
-    UpdateCumulativeEntropy(packet_number, &last_valid_entropy_);
-  }
-  while (map_offset_ < packet_number) {
-    packets_entropy_.pop_front();
-    ++map_offset_;
-  }
-  DVLOG(2) << "Cleared entropy before: " << packet_number;
-}
-
-}  // namespace net