Make RTCStatsReport::ToString() return JSON-parseable string.

webrtc/api/stats/rtcstats.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.
  */
 
@@ skipping 54 matching lines @@
   // Returns a vector of pointers to all the |RTCStatsMemberInterface| members
   // of this class. This allows for iteration of members. For a given class,
   // |Members| always returns the same members in the same order.
   std::vector<const RTCStatsMemberInterface*> Members() const;
   // Checks if the two stats objects are of the same type and have the same
   // member values. Timestamps are not compared. These operators are exposed for
   // testing.
   bool operator==(const RTCStats& other) const;
   bool operator!=(const RTCStats& other) const;
 
-  // Creates a human readable string representation of the stats object, listing
-  // all of its members (names and values).
-  std::string ToString() const;
+  // Creates a JSON readable string representation of the stats
+  // object, listing all of its members (names and values).
+  std::string ToJson() const;
 
   // Downcasts the stats object to an |RTCStats| subclass |T|. DCHECKs that the
   // object is of type |T|.
   template<typename T>
   const T& cast_to() const {
     RTC_DCHECK_EQ(type(), T::kType);
     return static_cast<const T&>(*this);
   }
 
  protected:
@@ skipping 127 matching lines @@
   virtual bool is_sequence() const = 0;
   virtual bool is_string() const = 0;
   bool is_defined() const { return is_defined_; }
   // Type and value comparator. The names are not compared. These operators are
   // exposed for testing.
   virtual bool operator==(const RTCStatsMemberInterface& other) const = 0;
   bool operator!=(const RTCStatsMemberInterface& other) const {
     return !(*this == other);
   }
   virtual std::string ValueToString() const = 0;
+  // This is the same as ValueToString except for kInt64 and kUint64 types,
+  // where the value is represented as a double instead of as an integer.
+  // Since JSON stores numbers as floating point numbers, very large integers
+  // cannot be accurately represented, so we prefer to display them as doubles
+  // instead.
+  virtual std::string ValueToJson() const = 0;
 
   template<typename T>
   const T& cast_to() const {
     RTC_DCHECK_EQ(type(), T::kType);
     return static_cast<const T&>(*this);
   }
 
  protected:
   RTCStatsMemberInterface(const char* name, bool is_defined)
       : name_(name), is_defined_(is_defined) {}
@@ skipping 35 matching lines @@
       return false;
     const RTCStatsMember<T>& other_t =
         static_cast<const RTCStatsMember<T>&>(other);
     if (!is_defined_)
       return !other_t.is_defined();
     if (!other.is_defined())
       return false;
     return value_ == other_t.value_;
   }
   std::string ValueToString() const override;
+  std::string ValueToJson() const override;
 
   // Assignment operators.
   T& operator=(const T& value) {
     value_ = value;
     is_defined_ = true;
     return value_;
   }
   T& operator=(const T&& value) {
     value_ = std::move(value);
     is_defined_ = true;
@@ skipping 26 matching lines @@
     return &value_;
   }
 
  private:
   T value_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_STATS_RTCSTATS_H_