RTCStats and RTCStatsReport added (webrtc/stats)

webrtc/api/rtcstatsreport.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_RTCSTATSREPORT_H_
+#define WEBRTC_API_RTCSTATSREPORT_H_
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "webrtc/api/rtcstats.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+
+namespace webrtc {
+
+// A collection of stats, maps from |RTCStats::id| to |RTCStats|.

[hta - Chromium, 2016/08/15 15:14:57]

Grammar nit:
"A collection of stats.
This is accessible as [if it was?] a map from |RTCStats::id| to |RTCStats|."

[hbos, 2016/08/15 22:46:43]

Done.

+class RTCStatsReport : public rtc::RefCountInterface {
+ public:
+  typedef std::map<std::string, std::unique_ptr<const RTCStats>> StatsMap;
+
+  class ConstIterator {
+   public:
+    ConstIterator(const ConstIterator&& other);
+    ~ConstIterator();
+
+    ConstIterator& operator++();
+    ConstIterator& operator++(int);
+    const RTCStats& operator*() const;
+    bool operator==(const ConstIterator& other) const;
+    bool operator!=(const ConstIterator& other) const;
+
+   private:
+    friend class RTCStatsReport;
+    ConstIterator(const rtc::scoped_refptr<const RTCStatsReport>& report,
+                  StatsMap::const_iterator it);
+
+    // Reference report to make sure it is kept alive.
+    rtc::scoped_refptr<const RTCStatsReport> report_;
+    StatsMap::const_iterator it_;
+  };
+
+  static rtc::scoped_refptr<RTCStatsReport> Create();
+
+  RTCStatsReport();
+  RTCStatsReport(const RTCStatsReport& other) = delete;
+
+  bool AddStats(std::unique_ptr<const RTCStats> stats);
+  const RTCStats* operator[](const std::string& id) const;
+  size_t size() const { return stats_.size(); }
+
+  ConstIterator begin() const;
+  ConstIterator end() const;
+
+  // Gets the subset of stats that are of type |T|, where |T| is any class
+  // descending from |RTCStats|.
+  template<typename T>
+  std::vector<const T*> GetStatsOfType() const {
+    std::vector<const T*> stats_of_type;
+    for (const RTCStats& stats : *this) {
+      if (stats.type() == &T::kType)
+        stats_of_type.push_back(&stats.to<const T>());
+    }
+    return stats_of_type;
+  }
+
+  friend class rtc::RefCountedObject<RTCStatsReport>;
+
+ private:
+  ~RTCStatsReport() override;
+
+  StatsMap stats_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_RTCSTATSREPORT_H_