Correct stats for RTCPeerConnectionStats.dataChannels[Opened/Closed].

webrtc/api/rtcstatscollector.h

 /*
  *  Copyright 2016 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.
  */
 
 #ifndef WEBRTC_API_RTCSTATSCOLLECTOR_H_
 #define WEBRTC_API_RTCSTATSCOLLECTOR_H_
 
 #include <map>
 #include <memory>
+#include <set>
 #include <vector>
 
+#include "webrtc/api/datachannel.h"
 #include "webrtc/api/datachannelinterface.h"
 #include "webrtc/api/stats/rtcstats_objects.h"
 #include "webrtc/api/stats/rtcstatsreport.h"
 #include "webrtc/base/asyncinvoker.h"
 #include "webrtc/base/refcount.h"
 #include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/sigslot.h"
 #include "webrtc/base/sslidentity.h"
 #include "webrtc/base/timeutils.h"
 
 namespace cricket {
 class Candidate;
 }  // namespace cricket
 
 namespace rtc {
 class SSLCertificate;
 }  // namespace rtc
 
 namespace webrtc {
 
 class PeerConnection;
 struct SessionStats;
 
 class RTCStatsCollectorCallback : public virtual rtc::RefCountInterface {
  public:
   virtual ~RTCStatsCollectorCallback() {}
 
   virtual void OnStatsDelivered(
       const rtc::scoped_refptr<const RTCStatsReport>& report) = 0;
 };
 
 // All public methods of the collector are to be called on the signaling thread.
 // Stats are gathered on the signaling, worker and network threads
 // asynchronously. The callback is invoked on the signaling thread. Resulting
 // reports are cached for |cache_lifetime_| ms.
-class RTCStatsCollector : public virtual rtc::RefCountInterface {
+class RTCStatsCollector : public virtual rtc::RefCountInterface,
+                          public sigslot::has_slots<> {
  public:
   static rtc::scoped_refptr<RTCStatsCollector> Create(
       PeerConnection* pc,
       int64_t cache_lifetime_us = 50 * rtc::kNumMicrosecsPerMillisec);
 
   // Gets a recent stats report. If there is a report cached that is still fresh
   // it is returned, otherwise new stats are gathered and returned. A report is
   // considered fresh for |cache_lifetime_| ms. const RTCStatsReports are safe
   // to use across multiple threads and may be destructed on any thread.
   void GetStatsReport(rtc::scoped_refptr<RTCStatsCollectorCallback> callback);
   // Clears the cache's reference to the most recent stats report. Subsequently
   // calling |GetStatsReport| guarantees fresh stats.
   void ClearCachedStatsReport();
 
+  // Exposed for testing only.
+  void OnDataChannelOpenedForTesting(DataChannel* channel);
+  void OnDataChannelClosedForTesting(DataChannel* channel);
+
  protected:
   RTCStatsCollector(PeerConnection* pc, int64_t cache_lifetime_us);
 
   // Stats gathering on a particular thread. Calls |AddPartialResults| before
   // returning. Virtual for the sake of testing.
   virtual void ProducePartialResultsOnSignalingThread(int64_t timestamp_us);
   virtual void ProducePartialResultsOnWorkerThread(int64_t timestamp_us);
   virtual void ProducePartialResultsOnNetworkThread(int64_t timestamp_us);
 
   // Can be called on any thread.
   void AddPartialResults(
       const rtc::scoped_refptr<RTCStatsReport>& partial_report);
 
  private:
+  // To allow |pc_| to wire up RTCStatsCollector::OnBlahBlah signal slots.
+  friend class PeerConnection;
+
   struct CertificateStatsPair {
     std::unique_ptr<rtc::SSLCertificateStats> local;
     std::unique_ptr<rtc::SSLCertificateStats> remote;
   };
 
   void AddPartialResults_s(rtc::scoped_refptr<RTCStatsReport> partial_report);
   void DeliverCachedReport();
 
   // Produces |RTCCertificateStats|.
   void ProduceCertificateStats_s(
@@ skipping 17 matching lines @@
   // Produces |RTCTransportStats|.
   void ProduceTransportStats_s(
       int64_t timestamp_us, const SessionStats& session_stats,
       const std::map<std::string, CertificateStatsPair>& transport_cert_stats,
       RTCStatsReport* report) const;
 
   // Helper function to stats-producing functions.
   std::map<std::string, CertificateStatsPair>
   PrepareTransportCertificateStats_s(const SessionStats& session_stats) const;
 
+  // Slots for signals (sigslot).
+  void OnDataChannelOpened(DataChannel* channel);
+  void OnDataChannelClosed(DataChannel* channel);
+
   PeerConnection* const pc_;
   rtc::Thread* const signaling_thread_;
   rtc::Thread* const worker_thread_;
   rtc::Thread* const network_thread_;
   rtc::AsyncInvoker invoker_;
 
   int num_pending_partial_reports_;
   int64_t partial_report_timestamp_us_;
   rtc::scoped_refptr<RTCStatsReport> partial_report_;
   std::vector<rtc::scoped_refptr<RTCStatsCollectorCallback>> callbacks_;
 
   // A timestamp, in microseconds, that is based on a timer that is
   // monotonically increasing. That is, even if the system clock is modified the
   // difference between the timer and this timestamp is how fresh the cached
   // report is.
   int64_t cache_timestamp_us_;
   int64_t cache_lifetime_us_;
   rtc::scoped_refptr<const RTCStatsReport> cached_report_;
+
+  // Data recorded and maintained by the stats collector during its lifetime.
+  // Some stats are produced from this record instead of other components.
+  struct InternalRecord {
+    InternalRecord() : data_channels_opened(0),
+                       data_channels_closed(0) {}
+
+    // The opened count goes up when a channel is fully opened and the closed
+    // count goes up if a previously opened channel has fully closed. The opened
+    // count does not go down when a channel closes, meaning (opened - closed)
+    // is the number of channels currently opened. A channel that is closed
+    // before reaching the open state does not affect these counters.
+    uint32_t data_channels_opened;
+    uint32_t data_channels_closed;
+    // Identifies by address channels that have been opened, which remain in the
+    // set until they have been fully closed.
+    std::set<uintptr_t> opened_data_channels;
+  };
+  InternalRecord internal_record_;
 };
 
 const char* CandidateTypeToRTCIceCandidateTypeForTesting(
     const std::string& type);
 const char* DataStateToRTCDataChannelStateForTesting(
     DataChannelInterface::DataState state);
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_RTCSTATSCOLLECTOR_H_