[Draft] RtpPacket sketched.

webrtc/modules/rtp_rtcp/source/rtp_packet_history.cc

Index: webrtc/modules/rtp_rtcp/source/rtp_packet_history.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_packet_history.cc b/webrtc/modules/rtp_rtcp/source/rtp_packet_history.cc
index 713fba87707c1a22b041aab31202b574482659eb..d96785d94c7040abc1a4065b02a32127b285ffd6 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_packet_history.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_packet_history.cc
@@ -10,17 +10,11 @@
 
 #include "webrtc/modules/rtp_rtcp/source/rtp_packet_history.h"
 
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>   // memset
-
 #include <algorithm>
 #include <limits>
-#include <set>
-
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
-#include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
+#include "webrtc/modules/rtp_rtcp/source/rtp_packet_to_send.h"
 
 namespace webrtc {
 
@@ -28,76 +22,62 @@ static const int kMinPacketRequestBytes = 50;
 
 RTPPacketHistory::RTPPacketHistory(Clock* clock)
     : clock_(clock),
-      store_(false),
       prev_index_(0) {}
 
 RTPPacketHistory::~RTPPacketHistory() {
 }
 
-void RTPPacketHistory::SetStorePacketsStatus(bool enable,
-                                             uint16_t number_to_store) {
-  rtc::CritScope cs(&critsect_);
-  if (enable) {
-    if (store_) {
+void RTPPacketHistory::SetStoreSize(uint16_t number_to_store) {
+  rtc::CritScope lock(&critsect_);
+  if (number_to_store > 0) {
+    if (!stored_packets_.empty()) {
       LOG(LS_WARNING) << "Purging packet history in order to re-set status.";
       Free();
     }
-    assert(!store_);
     Allocate(number_to_store);
   } else {
     Free();
   }
 }
 
+bool RTPPacketHistory::StorePackets() const {
+  rtc::CritScope lock(&critsect_);
+  return !stored_packets_.empty();
+}
+
 void RTPPacketHistory::Allocate(size_t number_to_store) {
-  assert(number_to_store > 0);
-  assert(number_to_store <= kMaxHistoryCapacity);
-  store_ = true;
+  RTC_DCHECK_GT(number_to_store, 0u);
+  RTC_DCHECK_LE(number_to_store, kMaxHistoryCapacity);
   stored_packets_.resize(number_to_store);
 }
 
 void RTPPacketHistory::Free() {
-  if (!store_) {
-    return;
-  }
-
   stored_packets_.clear();
-
-  store_ = false;
   prev_index_ = 0;
 }
 
-bool RTPPacketHistory::StorePackets() const {
-  rtc::CritScope cs(&critsect_);
-  return store_;
+RtpPacketToSend* RTPPacketHistory::PutRtpPacket(
+    std::unique_ptr<RtpPacketToSend>* packet,
+    StorageType type) {
+  RTC_DCHECK(packet);
+  RTC_DCHECK(*packet);
+  rtc::CritScope lock(&critsect_);
+  if (stored_packets_.empty())  // aka !StorePackets()
+    return packet->get();
+  RTC_DCHECK_LT(prev_index_, stored_packets_.size());
+  return StorePacket(std::move(*packet), type);
 }
 
-int32_t RTPPacketHistory::PutRTPPacket(const uint8_t* packet,
-                                       size_t packet_length,
-                                       int64_t capture_time_ms,
-                                       StorageType type) {
-  rtc::CritScope cs(&critsect_);
-  if (!store_) {
-    return 0;
-  }
-
-  assert(packet);
-  assert(packet_length > 3);
-
-  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];
-
+RtpPacketToSend* RTPPacketHistory::StorePacket(
+    std::unique_ptr<RtpPacketToSend> packet,
+    StorageType type) {
+  RTC_DCHECK(packet);
   // 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_packets_[prev_index_].length > 0 &&
-      stored_packets_[prev_index_].send_time == 0) {
-    size_t current_size = static_cast<uint16_t>(stored_packets_.size());
+  if (stored_packets_[prev_index_].packet &&
+      stored_packets_[prev_index_].packet->send_time_ms() == 0) {
+    size_t current_size = 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);
@@ -108,16 +88,13 @@ int32_t RTPPacketHistory::PutRTPPacket(const uint8_t* packet,
     }
   }
 
-  // Store packet
-  // TODO(sprang): Overhaul this class and get rid of this copy step.
-  //               (Finally introduce the RtpPacket class?)
-  memcpy(stored_packets_[prev_index_].data, packet, packet_length);
-  stored_packets_[prev_index_].length = packet_length;
+  RtpPacketToSend* stored_packet = packet.get();
+  if (packet->capture_time_ms() == 0)
+    packet->set_capture_time_ms(clock_->TimeInMilliseconds());
 
-  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.
+  RTC_DCHECK_EQ(packet->send_time_ms(), 0);
+  stored_packets_[prev_index_].sequence_number = packet->SequenceNumber();
+  stored_packets_[prev_index_].packet = std::move(packet);
   stored_packets_[prev_index_].storage_type = type;
   stored_packets_[prev_index_].has_been_retransmitted = false;
 
@@ -125,73 +102,24 @@ int32_t RTPPacketHistory::PutRTPPacket(const uint8_t* packet,
   if (prev_index_ >= stored_packets_.size()) {
     prev_index_ = 0;
   }
-  return 0;
+  return stored_packet;
 }
 
 bool RTPPacketHistory::HasRTPPacket(uint16_t sequence_number) const {
-  rtc::CritScope cs(&critsect_);
-  if (!store_) {
-    return false;
-  }
-
-  int32_t index = 0;
-  bool found = FindSeqNum(sequence_number, &index);
-  if (!found) {
-    return false;
-  }
-
-  if (stored_packets_[index].length == 0) {
-    // Invalid length.
-    return false;
-  }
-  return true;
-}
-
-bool RTPPacketHistory::SetSent(uint16_t sequence_number) {
-  rtc::CritScope cs(&critsect_);
-  if (!store_) {
-    return false;
-  }
-
-  int32_t index = 0;
-  bool found = FindSeqNum(sequence_number, &index);
-  if (!found) {
-    return false;
-  }
-
-  // Send time already set.
-  if (stored_packets_[index].send_time != 0) {
-    return false;
-  }
-
-  stored_packets_[index].send_time = clock_->TimeInMilliseconds();
-  return true;
+  rtc::CritScope lock(&critsect_);
+  size_t index = 0;
+  return FindSeqNum(sequence_number, &index);
 }
 
-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) {
-  rtc::CritScope cs(&critsect_);
-  RTC_CHECK_GE(*packet_length, static_cast<size_t>(IP_PACKET_SIZE));
-  if (!store_)
-    return false;
-
-  int32_t index = 0;
+RtpPacketToSend* RTPPacketHistory::GetPacket(uint16_t sequence_number,
+                                             int64_t min_elapsed_time_ms,
+                                             bool retransmit) {
+  rtc::CritScope lock(&critsect_);
+  size_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_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;
+    return nullptr;
   }
 
   // Verify elapsed time since last retrieve, but only for retransmissions and
@@ -199,60 +127,42 @@ bool RTPPacketHistory::GetPacketAndSetSendTime(uint16_t sequence_number,
   int64_t now = clock_->TimeInMilliseconds();
   if (min_elapsed_time_ms > 0 && retransmit &&
       stored_packets_[index].has_been_retransmitted &&
-      ((now - stored_packets_[index].send_time) < min_elapsed_time_ms)) {
-    return false;
+      ((now - stored_packets_[index].packet->send_time_ms()) <
+       min_elapsed_time_ms)) {
+    return nullptr;
   }
 
   if (retransmit) {
     if (stored_packets_[index].storage_type == kDontRetransmit) {
-      // No bytes copied since this packet shouldn't be retransmitted or is
-      // of zero size.
-      return false;
+      // Packet shouldn't be retransmitted or is of zero size.
+      return nullptr;
     }
     stored_packets_[index].has_been_retransmitted = true;
   }
-  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_packets_[index].length;
-  memcpy(packet, stored_packets_[index].data, length);
-  *packet_length = length;
-  *stored_time_ms = stored_packets_[index].time_ms;
+  return stored_packets_[index].packet.get();
 }
 
-bool RTPPacketHistory::GetBestFittingPacket(uint8_t* packet,
-                                            size_t* packet_length,
-                                            int64_t* stored_time_ms) {
-  rtc::CritScope cs(&critsect_);
-  if (!store_)
-    return false;
-  int index = FindBestFittingPacket(*packet_length);
+RtpPacketToSend* RTPPacketHistory::GetBestFittingPacket(size_t packet_length) {
+  rtc::CritScope lock(&critsect_);
+  int index = FindBestFittingPacket(packet_length);
   if (index < 0)
-    return false;
-  GetPacket(index, packet, packet_length, stored_time_ms);
-  return true;
+    return nullptr;
+  return stored_packets_[index].packet.get();
 }
 
-// private, lock should already be taken
 bool RTPPacketHistory::FindSeqNum(uint16_t sequence_number,
-                                  int32_t* index) const {
-  uint16_t temp_sequence_number = 0;
+                                  size_t* index) const {
+  if (stored_packets_.empty())
+    return false;
   if (prev_index_ > 0) {
     *index = prev_index_ - 1;
-    temp_sequence_number = stored_packets_[*index].sequence_number;
   } else {
-    *index = stored_packets_.size() - 1;
-    temp_sequence_number = stored_packets_[*index].sequence_number;  // wrap
+    *index = stored_packets_.size() - 1;  // wrap
   }
+  uint16_t temp_sequence_number = stored_packets_[*index].sequence_number;
 
-  int32_t idx = (prev_index_ - 1) - (temp_sequence_number - sequence_number);
+  int32_t idx = *index - (temp_sequence_number - sequence_number);
   if (idx >= 0 && idx < static_cast<int>(stored_packets_.size())) {
     *index = idx;
     temp_sequence_number = stored_packets_[*index].sequence_number;
@@ -268,11 +178,8 @@ bool RTPPacketHistory::FindSeqNum(uint16_t sequence_number,
       }
     }
   }
-  if (temp_sequence_number == sequence_number) {
-    // We found a match.
-    return true;
-  }
-  return false;
+  return temp_sequence_number == sequence_number &&
+         stored_packets_[*index].packet;
 }
 
 int RTPPacketHistory::FindBestFittingPacket(size_t size) const {
@@ -281,11 +188,11 @@ int RTPPacketHistory::FindBestFittingPacket(size_t size) const {
   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_packets_.size(); ++i) {
-    if (stored_packets_[i].length == 0)
+    if (!stored_packets_[i].packet)
       continue;
-    size_t diff = (stored_packets_[i].length > size)
-                      ? (stored_packets_[i].length - size)
-                      : (size - stored_packets_[i].length);
+    size_t diff = (stored_packets_[i].packet->size() > size)
+                      ? (stored_packets_[i].packet->size() - size)
+                      : (size - stored_packets_[i].packet->size());
     if (diff < min_diff) {
       min_diff = diff;
       best_index = static_cast<int>(i);
@@ -293,7 +200,4 @@ int RTPPacketHistory::FindBestFittingPacket(size_t size) const {
   }
   return best_index;
 }
-
-RTPPacketHistory::StoredPacket::StoredPacket() {}
-
 }  // namespace webrtc