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// Copyright 2016 the V8 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.
#ifndef V8_BASE_RING_BUFFER_H_
#define V8_BASE_RING_BUFFER_H_
#include "src/base/macros.h"
namespace v8 {
namespace base {
template <typename T>
class RingBuffer {
public:
RingBuffer() { Reset(); }
static const int kSize = 10;
void Push(const T& value) {
if (count_ == kSize) {
elements_[start_++] = value;
if (start_ == kSize) start_ = 0;
} else {
DCHECK_EQ(start_, 0);
elements_[count_++] = value;
}
}
int Count() const { return count_; }
template <typename Callback>
T Sum(Callback callback, const T& initial) const {
int j = start_ + count_ - 1;
if (j >= kSize) j -= kSize;
T result = initial;
for (int i = 0; i < count_; i++) {
result = callback(result, elements_[j]);
if (--j == -1) j += kSize;
}
return result;
}
void Reset() { start_ = count_ = 0; }
private:
T elements_[kSize];
int start_;
int count_;
DISALLOW_COPY_AND_ASSIGN(RingBuffer);
};
} // namespace base
} // namespace v8
#endif // V8_BASE_RING_BUFFER_H_
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