Line data    Source code

       1             : // Copyright 2016 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_BASE_RING_BUFFER_H_
       6             : #define V8_BASE_RING_BUFFER_H_
       7             : 
       8             : #include "src/base/macros.h"
       9             : 
      10             : namespace v8 {
      11             : namespace base {
      12             : 
      13             : template <typename T>
      14             : class RingBuffer {
      15             :  public:
      16     4842001 :   RingBuffer() { Reset(); }
      17             :   static const int kSize = 10;
      18      394417 :   void Push(const T& value) {
      19      488610 :     if (count_ == kSize) {
      20      243348 :       elements_[start_++] = value;
      21      243348 :       if (start_ == kSize) start_ = 0;
      22             :     } else {
      23             :       DCHECK_EQ(start_, 0);
      24      245262 :       elements_[count_++] = value;
      25             :     }
      26      394417 :   }
      27             : 
      28             :   int Count() const { return count_; }
      29             : 
      30             :   template <typename Callback>
      31      687912 :   T Sum(Callback callback, const T& initial) const {
      32      706485 :     int j = start_ + count_ - 1;
      33      706485 :     if (j >= kSize) j -= kSize;
      34      687912 :     T result = initial;
      35     4145090 :     for (int i = 0; i < count_; i++) {
      36      129526 :       result = callback(result, elements_[j]);
      37     3457178 :       if (--j == -1) j += kSize;
      38             :     }
      39      687912 :     return result;
      40             :   }
      41             : 
      42      440211 :   void Reset() { start_ = count_ = 0; }
      43             : 
      44             :  private:
      45             :   T elements_[kSize];
      46             :   int start_;
      47             :   int count_;
      48             :   DISALLOW_COPY_AND_ASSIGN(RingBuffer);
      49             : };
      50             : 
      51             : }  // namespace base
      52             : }  // namespace v8
      53             : 
      54             : #endif  // V8_BASE_RING_BUFFER_H_