1 files changed, 352 insertions, 0 deletions
diff --git a/libtransport/src/implementation/rtc_socket_producer.cc b/libtransport/src/implementation/rtc_socket_producer.cc
new file mode 100644
index 000000000..a5b2b4a0e
--- /dev/null
+++ b/libtransport/src/implementation/rtc_socket_producer.cc
@@ -0,0 +1,352 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <hicn/transport/interfaces/callbacks.h>
+
+#include <implementation/rtc_socket_producer.h>
+#include <stdlib.h>
+#include <time.h>
+
+#define NACK_HEADER_SIZE 8  // bytes
+#define TIMESTAMP_LEN 8     // bytes
+#define TCP_HEADER_SIZE 20
+#define IP6_HEADER_SIZE 40
+#define INIT_PACKET_PRODUCTION_RATE 100  // pps random value (almost 1Mbps)
+#define STATS_INTERVAL_DURATION 500      // ms
+#define INTEREST_LIFETIME_REDUCTION_FACTOR 0.8
+#define INACTIVE_TIME \
+  500                        // ms without producing before the socket
+                             // is considered inactive
+#define MILLI_IN_A_SEC 1000  // ms in a second
+
+#define HICN_MAX_DATA_SEQ 0xefffffff
+
+// slow production rate param
+#define MIN_PRODUCTION_RATE \
+  10  // in pacekts per sec. this value is computed
+      // through experiments
+#define LIFETIME_FRACTION 0.5
+
+// NACK HEADER
+//   +-----------------------------------------+
+//   | 4 bytes: current segment in production  |
+//   +-----------------------------------------+
+//   | 4 bytes: production rate (bytes x sec)  |
+//   +-----------------------------------------+
+//
+
+// PACKET HEADER
+//   +-----------------------------------------+
+//   | 8 bytes: TIMESTAMP                      |
+//   +-----------------------------------------+
+//   | packet                                  |
+//   +-----------------------------------------+
+
+namespace transport {
+namespace implementation {
+
+RTCProducerSocket::RTCProducerSocket(interface::ProducerSocket *producer_socket)
+    : ProducerSocket(producer_socket),
+      currentSeg_(1),
+      producedBytes_(0),
+      producedPackets_(0),
+      bytesProductionRate_(INIT_PACKET_PRODUCTION_RATE * 1400),
+      packetsProductionRate_(INIT_PACKET_PRODUCTION_RATE),
+      perSecondFactor_(MILLI_IN_A_SEC / STATS_INTERVAL_DURATION),
+      timer_on_(false) {
+  srand((unsigned int)time(NULL));
+  prodLabel_ = ((rand() % 255) << 24UL);
+  interests_cache_timer_ =
+      std::make_unique<asio::steady_timer>(this->getIoService());
+  round_timer_ = std::make_unique<asio::steady_timer>(this->getIoService());
+  setSocketOption(GeneralTransportOptions::OUTPUT_BUFFER_SIZE, 10000U);
+  scheduleRoundTimer();
+}
+
+RTCProducerSocket::~RTCProducerSocket() {}
+
+void RTCProducerSocket::registerPrefix(const Prefix &producer_namespace) {
+  ProducerSocket::registerPrefix(producer_namespace);
+
+  flowName_ = producer_namespace.getName();
+  auto family = flowName_.getAddressFamily();
+
+  switch (family) {
+    case AF_INET6:
+      headerSize_ = (uint32_t)Packet::getHeaderSizeFromFormat(HF_INET6_TCP);
+      break;
+    case AF_INET:
+      headerSize_ = (uint32_t)Packet::getHeaderSizeFromFormat(HF_INET_TCP);
+      break;
+    default:
+      throw errors::RuntimeException("Unknown name format.");
+  }
+}
+
+void RTCProducerSocket::scheduleRoundTimer() {
+  round_timer_->expires_from_now(
+      std::chrono::milliseconds(STATS_INTERVAL_DURATION));
+  round_timer_->async_wait([this](std::error_code ec) {
+    if (ec) return;
+    updateStats();
+  });
+}
+
+void RTCProducerSocket::updateStats() {
+  bytesProductionRate_ = producedBytes_.load() * perSecondFactor_;
+  packetsProductionRate_ = producedPackets_.load() * perSecondFactor_;
+  if (packetsProductionRate_.load() == 0) packetsProductionRate_ = 1;
+  producedBytes_ = 0;
+  producedPackets_ = 0;
+  scheduleRoundTimer();
+}
+
+void RTCProducerSocket::produce(std::unique_ptr<utils::MemBuf> &&buffer) {
+  auto buffer_size = buffer->length();
+
+  if (TRANSPORT_EXPECT_FALSE(buffer_size == 0)) {
+    return;
+  }
+
+  if (TRANSPORT_EXPECT_FALSE((buffer_size + headerSize_ + TIMESTAMP_LEN) >
+                             data_packet_size_)) {
+    return;
+  }
+
+  uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(
+                     std::chrono::steady_clock::now().time_since_epoch())
+                     .count();
+
+  producedBytes_ += (uint32_t)(buffer_size + headerSize_ + TIMESTAMP_LEN);
+  producedPackets_++;
+
+  Name n(flowName_);
+  auto content_object =
+      std::make_shared<ContentObject>(n.setSuffix(currentSeg_.load()));
+  auto payload = utils::MemBuf::create(TIMESTAMP_LEN);
+
+  memcpy(payload->writableData(), &now, TIMESTAMP_LEN);
+  payload->append(TIMESTAMP_LEN);
+  payload->prependChain(std::move(buffer));
+  content_object->appendPayload(std::move(payload));
+
+  content_object->setLifetime(500);  // XXX this should be set by the APP
+
+  content_object->setPathLabel(prodLabel_);
+
+  output_buffer_.insert(std::static_pointer_cast<ContentObject>(
+      content_object->shared_from_this()));
+
+  if (on_content_object_in_output_buffer_) {
+    on_content_object_in_output_buffer_(*getInterface(), *content_object);
+  }
+
+  TRANSPORT_LOGD("Send content %u (produce)",
+                 content_object->getName().getSuffix());
+  portal_->sendContentObject(*content_object);
+
+  if (on_content_object_output_) {
+    on_content_object_output_(*getInterface(), *content_object);
+  }
+
+  uint32_t old_curr = currentSeg_.load();
+  currentSeg_ = (currentSeg_.load() + 1) % HICN_MAX_DATA_SEQ;
+
+  // remove interests from the interest cache if it exists
+  // this generates nacks that will tell to the consumer
+  // that a new data packet was produced
+  utils::SpinLock::Acquire locked(interests_cache_lock_);
+  if (!seqs_map_.empty()) {
+    for (auto it = seqs_map_.begin(); it != seqs_map_.end(); it++) {
+      if (it->first != old_curr) sendNack(it->first);
+    }
+    seqs_map_.clear();
+    timers_map_.clear();
+  }
+}
+
+void RTCProducerSocket::onInterest(Interest::Ptr &&interest) {
+  uint32_t interestSeg = interest->getName().getSuffix();
+  uint32_t lifetime = interest->getLifetime();
+
+  if (on_interest_input_) {
+    on_interest_input_(*getInterface(), *interest);
+  }
+
+  uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(
+                     std::chrono::steady_clock::now().time_since_epoch())
+                     .count();
+
+  if (interestSeg > HICN_MAX_DATA_SEQ) {
+    sendNack(interestSeg);
+    return;
+  }
+
+  const std::shared_ptr<ContentObject> content_object =
+      output_buffer_.find(*interest);
+
+  if (content_object) {
+    if (on_interest_satisfied_output_buffer_) {
+      on_interest_satisfied_output_buffer_(*getInterface(), *interest);
+    }
+
+    if (on_content_object_output_) {
+      on_content_object_output_(*getInterface(), *content_object);
+    }
+
+    TRANSPORT_LOGD("Send content %u (onInterest)",
+                   content_object->getName().getSuffix());
+    portal_->sendContentObject(*content_object);
+    return;
+  } else {
+    if (on_interest_process_) {
+      on_interest_process_(*getInterface(), *interest);
+    }
+  }
+
+  // if the production rate is less than MIN_PRODUCTION_RATE we put the
+  // interest in a queue, otherwise we handle it in the usual way
+  if (packetsProductionRate_.load() < MIN_PRODUCTION_RATE &&
+      interestSeg >= currentSeg_.load()) {
+    utils::SpinLock::Acquire locked(interests_cache_lock_);
+
+    uint64_t next_timer = ~0;
+    if (!timers_map_.empty()) {
+      next_timer = timers_map_.begin()->first;
+    }
+
+    uint64_t expiration = now + (lifetime * LIFETIME_FRACTION);
+    // check if the seq number exists already
+    auto it_seqs = seqs_map_.find(interestSeg);
+    if (it_seqs != seqs_map_.end()) {
+      // the seq already exists
+      if (expiration < it_seqs->second) {
+        // we need to update the timer becasue we got a smaller one
+        // 1) remove the entry from the multimap
+        // 2) update this entry
+        auto range = timers_map_.equal_range(it_seqs->second);
+        for (auto it_timers = range.first; it_timers != range.second;
+             it_timers++) {
+          if (it_timers->second == it_seqs->first) {
+            timers_map_.erase(it_timers);
+            break;
+          }
+        }
+        timers_map_.insert(
+            std::pair<uint64_t, uint32_t>(expiration, interestSeg));
+        it_seqs->second = expiration;
+      } else {
+        // nothing to do here
+        return;
+      }
+    } else {
+      // add the new seq
+      timers_map_.insert(
+          std::pair<uint64_t, uint32_t>(expiration, interestSeg));
+      seqs_map_.insert(std::pair<uint32_t, uint64_t>(interestSeg, expiration));
+    }
+
+    // here we have at least one interest in the queue, we need to start or
+    // update the timer
+    if (!timer_on_) {
+      // set timeout
+      timer_on_ = true;
+      scheduleCacheTimer(timers_map_.begin()->first - now);
+    } else {
+      // re-schedule the timer because a new interest will expires sooner
+      if (next_timer > timers_map_.begin()->first) {
+        interests_cache_timer_->cancel();
+        scheduleCacheTimer(timers_map_.begin()->first - now);
+      }
+    }
+    return;
+  }
+
+  uint32_t max_gap = (uint32_t)floor(
+      (double)((double)((double)lifetime * INTEREST_LIFETIME_REDUCTION_FACTOR /
+                        1000.0) *
+               (double)packetsProductionRate_.load()));
+
+  if (interestSeg < currentSeg_.load() ||
+      interestSeg > (max_gap + currentSeg_.load())) {
+    sendNack(interestSeg);
+  }
+  // else drop packet
+}
+
+void RTCProducerSocket::scheduleCacheTimer(uint64_t wait) {
+  interests_cache_timer_->expires_from_now(std::chrono::milliseconds(wait));
+  interests_cache_timer_->async_wait([this](std::error_code ec) {
+    if (ec) return;
+    interestCacheTimer();
+  });
+}
+
+void RTCProducerSocket::interestCacheTimer() {
+  uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(
+                     std::chrono::steady_clock::now().time_since_epoch())
+                     .count();
+
+  utils::SpinLock::Acquire locked(interests_cache_lock_);
+
+  for (auto it_timers = timers_map_.begin(); it_timers != timers_map_.end();) {
+    uint64_t expire = it_timers->first;
+    if (expire <= now) {
+      uint32_t seq = it_timers->second;
+      sendNack(seq);
+      // remove the interest from the other map
+      seqs_map_.erase(seq);
+      it_timers = timers_map_.erase(it_timers);
+    } else {
+      // stop, we are done!
+      break;
+    }
+  }
+  if (timers_map_.empty()) {
+    timer_on_ = false;
+  } else {
+    timer_on_ = true;
+    scheduleCacheTimer(timers_map_.begin()->first - now);
+  }
+}
+
+void RTCProducerSocket::sendNack(uint32_t sequence) {
+  auto nack_payload = utils::MemBuf::create(NACK_HEADER_SIZE);
+  nack_payload->append(NACK_HEADER_SIZE);
+  ContentObject nack;
+
+  Name n(flowName_);
+  nack.appendPayload(std::move(nack_payload));
+  nack.setName(n.setSuffix(sequence));
+
+  uint32_t *payload_ptr = (uint32_t *)nack.getPayload()->data();
+  *payload_ptr = currentSeg_.load();
+
+  *(++payload_ptr) = bytesProductionRate_.load();
+
+  nack.setLifetime(0);
+  nack.setPathLabel(prodLabel_);
+
+  if (on_content_object_output_) {
+    on_content_object_output_(*getInterface(), nack);
+  }
+
+  TRANSPORT_LOGD("Send nack %u", sequence);
+  portal_->sendContentObject(nack);
+}
+
+}  // namespace implementation
+
+}  // end namespace transport