VWeb/Includes/Map.h

#pragma once

#include <cassert>
#include <mutex>
#include <unordered_map>
#include <condition_variable>
#include <atomic>

namespace VWeb {
template <typename T, typename S> struct SafeMap {
  explicit SafeMap(size_t maxSize = -1UL) : m_MaxSize(maxSize), m_End(false){};
  bool Add(const T &t, S &x) {
    std::unique_lock<std::mutex> lck(m_Mutex);
    while (m_Data.size() == m_MaxSize && !m_End)
      return false;
    assert(!m_End);
    m_Data.emplace(t, std::move(x));
    return true;
  };
  bool Add(T &&t, S &&x) {
    std::unique_lock<std::mutex> lck(m_Mutex);
    while (m_Data.size() == m_MaxSize && !m_End)
      return false;
    assert(!m_End);
    m_Data.push(std::move(t));
    return true;
  };
  void Remove(T t) {
    std::unique_lock<std::mutex> lck(m_Mutex);
    if (m_Data.empty() || m_End)
      return;
    if (m_Data.contains(t))
      m_Data.erase(t);
    m_CVFull.notify_one();
  };
  void Clear() {
    std::unique_lock<std::mutex> lck(m_Mutex);
    std::unordered_map<T, S> empty;
    std::swap(m_Data, empty);
    m_CVFull.notify_all();
  };
  bool Has(T t) {
    std::unique_lock<std::mutex> lck(m_Mutex);
    return m_Data.contains(t);
  };
  S &Get(T t) {
    std::unique_lock<std::mutex> lck(m_Mutex);
    return m_Data[t];
  };
  int Size() { return m_Data.size(); };

private:
  std::unordered_map<T, S> m_Data{};
  std::mutex m_Mutex{};
  std::condition_variable m_CVFull{};
  const size_t m_MaxSize{};
  std::atomic<bool> m_End{};
};
}