add high speed circular list

add test scenario

.vscode/settings.json

@@ -0,0 +1,26 @@
+{
+    "clang-format.executable": "clang-format-3.9",
+    "clang-format.fallbackStyle": "Google",
+    "files.associations": {
+        "*.tcc": "cpp",
+        "cctype": "cpp",
+        "clocale": "cpp",
+        "cstdint": "cpp",
+        "cstdio": "cpp",
+        "cstdlib": "cpp",
+        "cwchar": "cpp",
+        "cwctype": "cpp",
+        "exception": "cpp",
+        "initializer_list": "cpp",
+        "iosfwd": "cpp",
+        "iostream": "cpp",
+        "istream": "cpp",
+        "limits": "cpp",
+        "new": "cpp",
+        "ostream": "cpp",
+        "streambuf": "cpp",
+        "type_traits": "cpp",
+        "typeinfo": "cpp",
+        "chrono": "cpp"
+    },
+}

circular_list.h

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+#ifndef CIRCULAR_LIST_H
+#define CIRCULAR_LIST_H
+
+template <class T>
+class CirculaList {
+ public:
+  explicit CirculaList(int size) : size_(size) {
+    buf_ = new T[size_];
+    Clear();
+  }
+
+  inline int Count() { return (head_ - tail_) & (size_ - 1); }
+
+  inline int RemainingCapacity() { return (tail_ - (head_ + 1)) & (size_ - 1); }
+
+  inline bool IsEmpty() { return head_ == tail_; }
+
+  inline void Clear() { head_ = tail_ = 0; }
+
+  inline bool HasFreeSpace() { return RemainingCapacity() > 0; }
+
+  inline bool Push(T element) {
+    if (HasFreeSpace()) {
+      buf_[head_] = element;
+      head_ = (head_ + 1) & (size_ - 1);
+      return true;
+    } else
+      return false;
+  }
+
+  inline bool Pop(T &element) {
+    if (IsEmpty())
+      return false;
+    else {
+      element = buf_[tail_];
+      tail_ = (tail_ + 1) & (size_ - 1);
+      return true;
+    }
+  }
+  inline bool Top(T &element) {
+    if (IsEmpty())
+      return false;
+    else {
+      element = buf_[tail_];
+    }
+  }
+
+  inline bool At(int index, T &element) {
+    if (Count() <= index) return false;
+    element = buf_[(head_ + index) & (size_ - 1)];
+    return true;
+  }
+
+ private:
+  T *buf_;
+  int head_;
+  int tail_;
+  const int size_;
+};
+
+#endif  // !1

main.cpp

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+#include <chrono>
+#include <iostream>
+#include <string>
+#include "circular_list.h"
+
+#define MAX_SIZE 1048576
+using namespace std;
+
+#define CASE_11
+int main(int argc, char *[]) {
+  chrono::steady_clock::time_point begin = chrono::steady_clock::now();
+
+    CirculaList<int> list(MAX_SIZE);
+    for (int i = 0; i < MAX_SIZE; i++) list.Push(i);
+
+    int b = 0;
+
+    for (int i = MAX_SIZE - 1; i >= 0; i--) {
+      list.At(i, b);
+      // cout << std::to_string(b) << " ";
+    }
+    // cout << '\n';
+
+    for (int i = 0; i < MAX_SIZE; i++) list.Pop(b);
+
+  chrono::steady_clock::time_point end = chrono::steady_clock::now();
+
+  cout << "Time difference = "
+       << chrono::duration_cast<chrono::nanoseconds>(end - begin).count()
+       << endl;
+}