RTCStats equality operator added

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 45 matching lines @@
   virtual ~RTCStats() {}
 
   virtual std::unique_ptr<RTCStats> copy() const = 0;
 
   const std::string& id() const { return id_; }
   // Time relative to the UNIX epoch (Jan 1, 1970, UTC), in microseconds.
   int64_t timestamp_us() const { return timestamp_us_; }
   // Returns the static member variable |kType| of the implementing class.
   virtual const char* type() const = 0;
   // Returns a vector of pointers to all the RTCStatsMemberInterface members of
-  // this class. This allows for iteration of members.
+  // this class. This allows for iteration of members. The member order must be
+  // well-defined, the i-th member of two |RTCStats| objects of the same type
+  // must correspond to the same member.

[hta-webrtc, 2016/10/21 08:56:01]

This is a reflection of the fact that the Members() function is just an utility
over a struct-like object, where each member is always present in Members() even
if its is_present() is false.

Suggests rephrasing as:

For a given type, Members() always returns the same objects in the same order.

[hbos_chromium, 2016/10/21 18:59:18]

Done.

   std::vector<const RTCStatsMemberInterface*> Members() const;
+  // Checks if the two stats objects are of the same type and have the same
+  // member values.
+  bool operator==(const RTCStats& other) const;
+  bool operator!=(const RTCStats& other) const;
 
   // Creates a human readable string representation of the report, listing all
   // of its members (names and values).
   std::string ToString() 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);
@@ skipping 124 matching lines @@
     kSequenceString,        // std::vector<std::string>
   };
 
   virtual ~RTCStatsMemberInterface() {}
 
   const char* name() const { return name_; }
   virtual Type type() const = 0;
   virtual bool is_sequence() const = 0;
   virtual bool is_string() const = 0;
   bool is_defined() const { return is_defined_; }
+  // Type and value comparator (can be true even if name and type isn't).

[hta-webrtc, 2016/10/21 08:56:01]

Even if name and type isn't what?

[hbos_chromium, 2016/10/21 18:59:18]

That was a bit nonsensey. Changed to "Type and value comparator. The names are
not compared."

+  virtual bool operator==(const RTCStatsMemberInterface& other) const = 0;
+  bool operator!=(const RTCStatsMemberInterface& other) const {
+    return !(*this == other);
+  }
   virtual std::string ValueToString() 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)
@@ skipping 24 matching lines @@
   explicit RTCStatsMember(const RTCStatsMember<T>& other)
       : RTCStatsMemberInterface(other.name_, other.is_defined_),
         value_(other.value_) {}
   explicit RTCStatsMember(RTCStatsMember<T>&& other)
       : RTCStatsMemberInterface(other.name_, other.is_defined_),
         value_(std::move(other.value_)) {}
 
   Type type() const override { return kType; }
   bool is_sequence() const override;
   bool is_string() const override;
+  bool operator==(const RTCStatsMemberInterface& other) const override {
+    if (type() != other.type())
+      return false;
+    const RTCStatsMember<T>& other_t =
+        static_cast<const RTCStatsMember<T>&>(other);
+    if (!is_defined_)
+      return !other_t.is_defined();
+    return value_ == other_t.value_;
+  }

[hta-webrtc, 2016/10/21 08:56:01]

Didn't the presubmit check yell at you over having an inline function this long?

git cl presubmit

[hbos_chromium, 2016/10/21 18:59:18]

It does not, this is a template class.

   std::string ValueToString() 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);
@@ skipping 27 matching lines @@
     return &value_;
   }
 
  private:
   T value_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_STATS_RTCSTATS_H_