Make AudioVector::operator[] inline and modify index calculation

webrtc/modules/audio_coding/neteq/audio_vector.h

 /*
  *  Copyright (c) 2012 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_MODULES_AUDIO_CODING_NETEQ_AUDIO_VECTOR_H_
 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_AUDIO_VECTOR_H_
 
 #include <string.h>  // Access to size_t.
 #include <memory>
 
+#include "webrtc/base/checks.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 class AudioVector {
  public:
   // Creates an empty AudioVector.
   AudioVector();
 
@@ skipping 76 matching lines @@
   // region.
   virtual void CrossFade(const AudioVector& append_this, size_t fade_length);
 
   // Returns the number of elements in this AudioVector.
   virtual size_t Size() const;
 
   // Returns true if this AudioVector is empty.
   virtual bool Empty() const;
 
   // Accesses and modifies an element of AudioVector.
-  const int16_t& operator[](size_t index) const;
-  int16_t& operator[](size_t index);
+  inline const int16_t& operator[](size_t index) const {

[kwiberg-webrtc, 2017/02/13 14:44:08]

You should also DCHECK that begin_index_ + index doesn't overflow:

  RTC_DCHECK_GE(begin_index_ + index, index);

[hlundin-webrtc, 2017/02/14 08:49:28]

Done.

+    const size_t ix = begin_index_ + index >= capacity_ ?
+      begin_index_ + index - capacity_ :
+      begin_index_ + index;
+    RTC_DCHECK_LT(ix, capacity_);
+    return array_[ix];
+  }
+
+  inline int16_t& operator[](size_t index) {
+    const size_t ix = begin_index_ + index >= capacity_ ?
+      begin_index_ + index - capacity_ :
+      begin_index_ + index;
+    RTC_DCHECK_LT(ix, capacity_);

[kwiberg-webrtc, 2017/02/13 14:44:08]

Break out the index calculation to a separate function? You could make it
private static inline, I think...

[hlundin-webrtc, 2017/02/14 08:49:28]

Done.

+    return array_[ix];
+  }
 
  private:
   static const size_t kDefaultInitialSize = 10;
 
   void Reserve(size_t n);
 
   void InsertByPushBack(const int16_t* insert_this, size_t length,
                         size_t position);
 
   void InsertByPushFront(const int16_t* insert_this, size_t length,
@@ skipping 12 matching lines @@
   size_t begin_index_;
 
   // The index of the sample after the last sample in |array_|.
   size_t end_index_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(AudioVector);
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_AUDIO_VECTOR_H_