text: // Copyright (c) 2014-2019, The Monero Project
  // 
  // All rights reserved.
  // 
  // Redistribution and use in source and binary forms, with or without modification, are
  // permitted provided that the following conditions are met:
  // 
  // 1. Redistributions of source code must retain the above copyright notice, this list of
  //    conditions and the following disclaimer.
  // 
  // 2. Redistributions in binary form must reproduce the above copyright notice, this list
  //    of conditions and the following disclaimer in the documentation and/or other
  //    materials provided with the distribution.
  // 
  // 3. Neither the name of the copyright holder nor the names of its contributors may be
  //    used to endorse or promote products derived from this software without specific
  //    prior written permission.
  // 
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  // 
  // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
  
  #pragma once
  
  #include <atomic>
  
  #include <boost/asio/io_service.hpp>
  #include <boost/uuid/uuid_io.hpp>
  
  #include "include_base_utils.h"
  #include "string_tools.h"
  #include "net/levin_protocol_handler_async.h"
  #include "net/abstract_tcp_server2.h"
  #include "serialization/keyvalue_serialization.h"
  
  #include "../unit_tests/unit_tests_utils.h"
  
  namespace net_load_tests
  {
    struct test_connection_context : epee::net_utils::connection_context_base
    {
      volatile bool m_closed;
    };
  
    typedef epee::levin::async_protocol_handler<test_connection_context> test_levin_protocol_handler;
    typedef epee::levin::async_protocol_handler_config<test_connection_context> test_levin_protocol_handler_config;
    typedef epee::net_utils::connection<test_levin_protocol_handler> test_connection;
    typedef epee::net_utils::boosted_tcp_server<test_levin_protocol_handler> test_tcp_server;
  
    struct test_levin_commands_handler : public epee::levin::levin_commands_handler<test_connection_context>
    {
      test_levin_commands_handler()
        //: m_return_code(LEVIN_OK)
        //, m_last_command(-1)
      {
      }
  
      virtual int invoke(int command, const epee::span<const uint8_t> in_buff, std::string& buff_out, test_connection_context& context)
      {
        //m_invoke_counter.inc();
        //std::unique_lock<std::mutex> lock(m_mutex);
        //m_last_command = command;
        //m_last_in_buf = in_buff;
        //buff_out = m_invoke_out_buf;
        //return m_return_code;
        return LEVIN_OK;
      }
  
      virtual int notify(int command, const epee::span<const uint8_t> in_buff, test_connection_context& context)
      {
        //m_notify_counter.inc();
        //std::unique_lock<std::mutex> lock(m_mutex);
        //m_last_command = command;
        //m_last_in_buf = in_buff;
        //return m_return_code;
        return LEVIN_OK;
      }
  
      virtual void callback(test_connection_context& context)
      {
        //m_callback_counter.inc();
        //std::cout << "test_levin_commands_handler::callback()" << std::endl;
      }
  
      virtual void on_connection_new(test_connection_context& context)
      {
        m_new_connection_counter.inc();
        //std::cout << "test_levin_commands_handler::on_connection_new()" << std::endl;
      }
  
      virtual void on_connection_close(test_connection_context& context)
      {
        m_close_connection_counter.inc();
        //std::cout << "test_levin_commands_handler::on_connection_close()" << std::endl;
      }
  
      //size_t invoke_counter() const { return m_invoke_counter.get(); }
      //size_t notify_counter() const { return m_notify_counter.get(); }
      //size_t callback_counter() const { return m_callback_counter.get(); }
      size_t new_connection_counter() const { return m_new_connection_counter.get(); }
      size_t close_connection_counter() const { return m_close_connection_counter.get(); }
  
      //int return_code() const { return m_return_code; }
      //void return_code(int v) { m_return_code = v; }
  
      //const std::string& invoke_out_buf() const { return m_invoke_out_buf; }
      //void invoke_out_buf(const std::string& v) { m_invoke_out_buf = v; }
  
      //int last_command() const { return m_last_command; }
      //const std::string& last_in_buf() const { return m_last_in_buf; }
  
    protected:
      //unit_test::call_counter m_invoke_counter;
      //unit_test::call_counter m_notify_counter;
      //unit_test::call_counter m_callback_counter;
      unit_test::call_counter m_new_connection_counter;
      unit_test::call_counter m_close_connection_counter;
  
      //std::mutex m_mutex;
  
      //int m_return_code;
      //std::string m_invoke_out_buf;
  
      //int m_last_command;
      //std::string m_last_in_buf;
    };
  
    class open_close_test_helper
    {
    public:
      open_close_test_helper(test_tcp_server& tcp_server, size_t open_request_target, size_t max_opened_connection_count)
        : m_tcp_server(tcp_server)
        , m_max_opened_connection_count(max_opened_connection_count)
        , m_opened_connection_count(0)
        , m_next_opened_conn_idx(0)
        , m_next_closed_conn_idx(0)
        , m_connections(open_request_target)
      {
        for (auto& conn_id : m_connections)
          conn_id = boost::uuids::nil_uuid();
      }
  
      bool handle_new_connection(const boost::uuids::uuid& connection_id, bool ignore_close_fails = false)
      {
        size_t idx = m_next_opened_conn_idx.fetch_add(1, std::memory_order_relaxed);
        if (idx >= m_connections.size())
        {
          LOG_PRINT_L0("ERROR: connections overflow");
          exit(1);
        }
        m_connections[idx] = connection_id;
  
        size_t prev_connection_count = m_opened_connection_count.fetch_add(1, std::memory_order_relaxed);
        if (m_max_opened_connection_count <= prev_connection_count)
        {
          return close_next_connection(ignore_close_fails);
        }
  
        return true;
      }
  
      void close_remaining_connections()
      {
        while (close_next_connection(false));
      }
  
      bool close_next_connection(bool ignore_close_fails)
      {
        size_t idx = m_next_closed_conn_idx.fetch_add(1, std::memory_order_relaxed);
        if (m_next_opened_conn_idx.load(std::memory_order_relaxed) <= idx)
        {
          LOG_PRINT_L0("Not enough opened connections");
          return false;
        }
        if (m_connections[idx].is_nil())
        {
          LOG_PRINT_L0("Connection isn't opened");
          return false;
        }
        if (!m_tcp_server.get_config_object().close(m_connections[idx]))
        {
          LOG_PRINT_L0("Close connection error: " << m_connections[idx]);
          if (!ignore_close_fails)
          {
            return false;
          }
        }
  
        m_connections[idx] = boost::uuids::nil_uuid();
        m_opened_connection_count.fetch_sub(1, std::memory_order_relaxed);
        return true;
      }
  
      size_t opened_connection_count() const { return m_opened_connection_count.load(std::memory_order_relaxed); }
  
    private:
      test_tcp_server& m_tcp_server;
      size_t m_max_opened_connection_count;
      std::atomic<size_t> m_opened_connection_count;
      std::atomic<size_t> m_next_opened_conn_idx;
      std::atomic<size_t> m_next_closed_conn_idx;
      std::vector<boost::uuids::uuid> m_connections;
    };
  
    const unsigned int min_thread_count = 2;
    const std::string clt_port("36230");
    const std::string srv_port("36231");
  
    enum command_ids
    {
      cmd_close_all_connections_id = 73564,
      cmd_start_open_close_test_id,
      cmd_get_statistics_id,
      cmd_reset_statistics_id,
      cmd_shutdown_id,
      cmd_send_data_requests_id,
      cmd_data_request_id
    };
  
    struct CMD_CLOSE_ALL_CONNECTIONS
    {
      const static int ID = cmd_close_all_connections_id;
  
      struct request
      {
        BEGIN_KV_SERIALIZE_MAP()
        END_KV_SERIALIZE_MAP()
      };
    };
  
    struct CMD_START_OPEN_CLOSE_TEST
    {
      const static int ID = cmd_start_open_close_test_id;
  
      struct request
      {
        uint64_t open_request_target;
        uint64_t max_opened_conn_count;
  
        BEGIN_KV_SERIALIZE_MAP()
          KV_SERIALIZE(open_request_target)
          KV_SERIALIZE(max_opened_conn_count)
        END_KV_SERIALIZE_MAP()
      };
  
      struct response
      {
        BEGIN_KV_SERIALIZE_MAP()
        END_KV_SERIALIZE_MAP()
      };
    };
  
    struct CMD_GET_STATISTICS
    {
      const static int ID = cmd_get_statistics_id;
  
      struct request
      {
        BEGIN_KV_SERIALIZE_MAP()
        END_KV_SERIALIZE_MAP()
      };
  
      struct response
      {
        uint64_t opened_connections_count;
        uint64_t new_connection_counter;
        uint64_t close_connection_counter;
  
        BEGIN_KV_SERIALIZE_MAP()
          KV_SERIALIZE(opened_connections_count)
          KV_SERIALIZE(new_connection_counter)
          KV_SERIALIZE(close_connection_counter)
        END_KV_SERIALIZE_MAP()
  
        std::string to_string() const
        {
          std::stringstream ss;
          ss << "opened_connections_count = " << opened_connections_count <<
            ", new_connection_counter = " << new_connection_counter <<
            ", close_connection_counter = " << close_connection_counter;
          return ss.str();
        }
      };
    };
  
    struct CMD_RESET_STATISTICS
    {
      const static int ID = cmd_reset_statistics_id;
  
      struct request
      {
        BEGIN_KV_SERIALIZE_MAP()
        END_KV_SERIALIZE_MAP()
      };
  
      struct response
      {
        BEGIN_KV_SERIALIZE_MAP()
        END_KV_SERIALIZE_MAP()
      };
    };
  
    struct CMD_SHUTDOWN
    {
      const static int ID = cmd_shutdown_id;
  
      struct request
      {
        BEGIN_KV_SERIALIZE_MAP()
        END_KV_SERIALIZE_MAP()
      };
    };
  
    struct CMD_SEND_DATA_REQUESTS
    {
      const static int ID = cmd_send_data_requests_id;
  
      struct request
      {
        uint64_t request_size;
  
        BEGIN_KV_SERIALIZE_MAP()
          KV_SERIALIZE(request_size)
        END_KV_SERIALIZE_MAP()
      };
    };
  
    struct CMD_DATA_REQUEST
    {
      const static int ID = cmd_data_request_id;
  
      struct request
      {
        std::string data;
        uint64_t response_size;
  
        BEGIN_KV_SERIALIZE_MAP()
          KV_SERIALIZE(data)
        END_KV_SERIALIZE_MAP()
      };
  
      struct response
      {
        std::string data;
  
        BEGIN_KV_SERIALIZE_MAP()
          KV_SERIALIZE(data)
        END_KV_SERIALIZE_MAP()
      };
    };
  }
  