Refactor RTPPacketHistory to use a packet struct.

webrtc/modules/rtp_rtcp/source/rtp_packet_history.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/modules/rtp_rtcp/source/rtp_packet_history.h"
 
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>   // memset
 #include <limits>
 #include <set>
 
 #include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
 #include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/interface/logging.h"
 
 namespace webrtc {
 
 static const int kMinPacketRequestBytes = 50;
 
 RTPPacketHistory::RTPPacketHistory(Clock* clock)
-  : clock_(clock),
-    critsect_(CriticalSectionWrapper::CreateCriticalSection()),
-    store_(false),
-    prev_index_(0),
-    max_packet_length_(0) {
-}
+    : clock_(clock),
+      critsect_(CriticalSectionWrapper::CreateCriticalSection()),
+      store_(false),
+      prev_index_(0) {}
 
 RTPPacketHistory::~RTPPacketHistory() {
 }
 
 void RTPPacketHistory::SetStorePacketsStatus(bool enable,
                                              uint16_t number_to_store) {
   CriticalSectionScoped cs(critsect_.get());
   if (enable) {
     if (store_) {
       LOG(LS_WARNING) << "Purging packet history in order to re-set status.";
       Free();
     }
     assert(!store_);
     Allocate(number_to_store);
   } else {
     Free();
   }
 }
 
 void RTPPacketHistory::Allocate(size_t number_to_store) {
   assert(number_to_store > 0);
   assert(number_to_store <= kMaxHistoryCapacity);
   store_ = true;
   stored_packets_.resize(number_to_store);
-  stored_seq_nums_.resize(number_to_store);
-  stored_lengths_.resize(number_to_store);
-  stored_times_.resize(number_to_store);
-  stored_send_times_.resize(number_to_store);
-  stored_types_.resize(number_to_store);
 }
 
 void RTPPacketHistory::Free() {
   if (!store_) {
     return;
   }
 
-  std::vector<std::vector<uint8_t> >::iterator it;
-  for (it = stored_packets_.begin(); it != stored_packets_.end(); ++it) {
-    it->clear();
-  }
-
   stored_packets_.clear();
-  stored_seq_nums_.clear();
-  stored_lengths_.clear();
-  stored_times_.clear();
-  stored_send_times_.clear();
-  stored_types_.clear();
 
   store_ = false;
   prev_index_ = 0;
-  max_packet_length_ = 0;
 }
 
 bool RTPPacketHistory::StorePackets() const {
   CriticalSectionScoped cs(critsect_.get());
   return store_;
 }
 
-void RTPPacketHistory::VerifyAndAllocatePacketLength(size_t packet_length,
-                                                     uint32_t start_index) {
-  assert(packet_length > 0);
-  if (!store_) {
-    return;
-  }
-
-  // If start_index > 0 this is a resize and we must check any new (empty)
-  // packets created during the resize.
-  if (start_index == 0 && packet_length <= max_packet_length_) {
-    return;
-  }
-
-  max_packet_length_ = std::max(packet_length, max_packet_length_);
-
-  std::vector<std::vector<uint8_t> >::iterator it;
-  for (it = stored_packets_.begin() + start_index; it != stored_packets_.end();
-       ++it) {
-    it->resize(max_packet_length_);
-  }
-}
-
 int32_t RTPPacketHistory::PutRTPPacket(const uint8_t* packet,
                                        size_t packet_length,
-                                       size_t max_packet_length,
                                        int64_t capture_time_ms,
                                        StorageType type) {
   if (type == kDontStore) {
     return 0;
   }
 
   CriticalSectionScoped cs(critsect_.get());
   if (!store_) {
     return 0;
   }
 
   assert(packet);
   assert(packet_length > 3);
 
-  VerifyAndAllocatePacketLength(max_packet_length, 0);
-
-  if (packet_length > max_packet_length_) {
+  if (packet_length > IP_PACKET_SIZE) {
     LOG(LS_WARNING) << "Failed to store RTP packet with length: "
                     << packet_length;
     return -1;
   }
 
   const uint16_t seq_num = (packet[2] << 8) + packet[3];
 
   // If index we're about to overwrite contains a packet that has not
   // yet been sent (probably pending in paced sender), we need to expand
   // the buffer.
-  if (stored_lengths_[prev_index_] > 0 &&
-      stored_send_times_[prev_index_] == 0) {
+  if (stored_packets_[prev_index_].length > 0 &&
+      stored_packets_[prev_index_].send_time == 0) {
     size_t current_size = static_cast<uint16_t>(stored_packets_.size());
     if (current_size < kMaxHistoryCapacity) {
       size_t expanded_size = std::max(current_size * 3 / 2, current_size + 1);
       expanded_size = std::min(expanded_size, kMaxHistoryCapacity);
       Allocate(expanded_size);
-      VerifyAndAllocatePacketLength(max_packet_length, current_size);
       // Causes discontinuity, but that's OK-ish. FindSeqNum() will still work,
       // but may be slower - at least until buffer has wrapped around once.
       prev_index_ = current_size;
     }
   }
 
   // Store packet
-  std::vector<std::vector<uint8_t> >::iterator it =
-      stored_packets_.begin() + prev_index_;
   // TODO(sprang): Overhaul this class and get rid of this copy step.
   //               (Finally introduce the RtpPacket class?)
-  std::copy(packet, packet + packet_length, it->begin());
+  memcpy(stored_packets_[prev_index_].data, packet, packet_length);
+  stored_packets_[prev_index_].length = packet_length;
 
-  stored_seq_nums_[prev_index_] = seq_num;
-  stored_lengths_[prev_index_] = packet_length;
-  stored_times_[prev_index_] = (capture_time_ms > 0) ? capture_time_ms :
-      clock_->TimeInMilliseconds();
-  stored_send_times_[prev_index_] = 0;  // Packet not sent.
-  stored_types_[prev_index_] = type;
+  stored_packets_[prev_index_].sequence_number = seq_num;
+  stored_packets_[prev_index_].time_ms =
+      (capture_time_ms > 0) ? capture_time_ms : clock_->TimeInMilliseconds();
+  stored_packets_[prev_index_].send_time = 0;  // Packet not sent.
+  stored_packets_[prev_index_].storage_type = type;
 
   ++prev_index_;
-  if (prev_index_ >= stored_seq_nums_.size()) {
+  if (prev_index_ >= stored_packets_.size()) {
     prev_index_ = 0;
   }
   return 0;
 }
 
 bool RTPPacketHistory::HasRTPPacket(uint16_t sequence_number) const {
   CriticalSectionScoped cs(critsect_.get());
   if (!store_) {
     return false;
   }
 
   int32_t index = 0;
   bool found = FindSeqNum(sequence_number, &index);
   if (!found) {
     return false;
   }
 
-  size_t length = stored_lengths_.at(index);
-  if (length == 0 || length > max_packet_length_) {
+  if (stored_packets_[index].length == 0) {
     // Invalid length.
     return false;
   }
   return true;
 }
 
 bool RTPPacketHistory::SetSent(uint16_t sequence_number) {
   CriticalSectionScoped cs(critsect_.get());
   if (!store_) {
     return false;
   }
 
   int32_t index = 0;
   bool found = FindSeqNum(sequence_number, &index);
   if (!found) {
     return false;
   }
 
   // Send time already set.
-  if (stored_send_times_[index] != 0) {
+  if (stored_packets_[index].send_time != 0) {
     return false;
   }
 
-  stored_send_times_[index] = clock_->TimeInMilliseconds();
+  stored_packets_[index].send_time = clock_->TimeInMilliseconds();
   return true;
 }
 
 bool RTPPacketHistory::GetPacketAndSetSendTime(uint16_t sequence_number,
                                                int64_t min_elapsed_time_ms,
                                                bool retransmit,
                                                uint8_t* packet,
                                                size_t* packet_length,
                                                int64_t* stored_time_ms) {
   CriticalSectionScoped cs(critsect_.get());
-  assert(*packet_length >= max_packet_length_);
+  assert(*packet_length >= IP_PACKET_SIZE);
   if (!store_) {
     return false;
   }
 
   int32_t index = 0;
   bool found = FindSeqNum(sequence_number, &index);
   if (!found) {
     LOG(LS_WARNING) << "No match for getting seqNum " << sequence_number;
     return false;
   }
 
-  size_t length = stored_lengths_.at(index);
-  assert(length <= max_packet_length_);
+  size_t length = stored_packets_[index].length;
+  assert(length <= IP_PACKET_SIZE);
   if (length == 0) {
     LOG(LS_WARNING) << "No match for getting seqNum " << sequence_number
                     << ", len " << length;
     return false;
   }
 
   // Verify elapsed time since last retrieve.
   int64_t now = clock_->TimeInMilliseconds();
   if (min_elapsed_time_ms > 0 &&
-      ((now - stored_send_times_.at(index)) < min_elapsed_time_ms)) {
+      ((now - stored_packets_[index].send_time) < min_elapsed_time_ms)) {
     return false;
   }
 
-  if (retransmit && stored_types_.at(index) == kDontRetransmit) {
+  if (retransmit && stored_packets_[index].storage_type == kDontRetransmit) {
     // No bytes copied since this packet shouldn't be retransmitted or is
     // of zero size.
     return false;
   }
-  stored_send_times_[index] = clock_->TimeInMilliseconds();
+  stored_packets_[index].send_time = clock_->TimeInMilliseconds();
   GetPacket(index, packet, packet_length, stored_time_ms);
   return true;
 }
 
 void RTPPacketHistory::GetPacket(int index,
                                  uint8_t* packet,
                                  size_t* packet_length,
                                  int64_t* stored_time_ms) const {
   // Get packet.
-  size_t length = stored_lengths_.at(index);
-  std::vector<std::vector<uint8_t> >::const_iterator it_found_packet =
-      stored_packets_.begin() + index;
-  std::copy(it_found_packet->begin(), it_found_packet->begin() + length,
-            packet);
+  size_t length = stored_packets_[index].length;
+  memcpy(packet, stored_packets_[index].data, length);
   *packet_length = length;
-  *stored_time_ms = stored_times_.at(index);
+  *stored_time_ms = stored_packets_[index].time_ms;
 }
 
 bool RTPPacketHistory::GetBestFittingPacket(uint8_t* packet,
                                             size_t* packet_length,
                                             int64_t* stored_time_ms) {
   CriticalSectionScoped cs(critsect_.get());
   if (!store_)
     return false;
   int index = FindBestFittingPacket(*packet_length);
   if (index < 0)
     return false;
   GetPacket(index, packet, packet_length, stored_time_ms);
   return true;
 }
 
 // private, lock should already be taken
 bool RTPPacketHistory::FindSeqNum(uint16_t sequence_number,
                                   int32_t* index) const {
   uint16_t temp_sequence_number = 0;
   if (prev_index_ > 0) {
     *index = prev_index_ - 1;
-    temp_sequence_number = stored_seq_nums_[*index];
+    temp_sequence_number = stored_packets_[*index].sequence_number;
   } else {
-    *index = stored_seq_nums_.size() - 1;
-    temp_sequence_number = stored_seq_nums_[*index];  // wrap
+    *index = stored_packets_.size() - 1;
+    temp_sequence_number = stored_packets_[*index].sequence_number;  // wrap
   }
 
   int32_t idx = (prev_index_ - 1) - (temp_sequence_number - sequence_number);
-  if (idx >= 0 && idx < static_cast<int>(stored_seq_nums_.size())) {
+  if (idx >= 0 && idx < static_cast<int>(stored_packets_.size())) {
     *index = idx;
-    temp_sequence_number = stored_seq_nums_[*index];
+    temp_sequence_number = stored_packets_[*index].sequence_number;
   }
 
   if (temp_sequence_number != sequence_number) {
     // We did not found a match, search all.
-    for (uint16_t m = 0; m < stored_seq_nums_.size(); m++) {
-      if (stored_seq_nums_[m] == sequence_number) {
+    for (uint16_t m = 0; m < stored_packets_.size(); m++) {
+      if (stored_packets_[m].sequence_number == sequence_number) {
         *index = m;
-        temp_sequence_number = stored_seq_nums_[*index];
+        temp_sequence_number = stored_packets_[*index].sequence_number;
         break;
       }
     }
   }
   if (temp_sequence_number == sequence_number) {
     // We found a match.
     return true;
   }
   return false;
 }
 
 int RTPPacketHistory::FindBestFittingPacket(size_t size) const {
-  if (size < kMinPacketRequestBytes || stored_lengths_.empty())
+  if (size < kMinPacketRequestBytes || stored_packets_.empty())
     return -1;
   size_t min_diff = std::numeric_limits<size_t>::max();
   int best_index = -1;  // Returned unchanged if we don't find anything.
-  for (size_t i = 0; i < stored_lengths_.size(); ++i) {
-    if (stored_lengths_[i] == 0)
+  for (size_t i = 0; i < stored_packets_.size(); ++i) {
+    if (stored_packets_[i].length == 0)
       continue;
-    size_t diff = (stored_lengths_[i] > size) ?
-        (stored_lengths_[i] - size) : (size - stored_lengths_[i]);
+    size_t diff = (stored_packets_[i].length > size)
+                      ? (stored_packets_[i].length - size)
+                      : (size - stored_packets_[i].length);
     if (diff < min_diff) {
       min_diff = diff;
       best_index = static_cast<int>(i);
     }
   }
   return best_index;
 }
+
+RTPPacketHistory::StoredPacket::StoredPacket() {}
+
 }  // namespace webrtc