asio: initial idf port of asio library without ssl

* Original commit: espressif/esp-idf@1ef13c524c

examples/protocols/asio/chat_server/main/Kconfig.projbuild

@@ -0,0 +1,21 @@
+menu "Example Configuration"
+
+config ESP_WIFI_SSID
+    string "WiFi SSID"
+    default "myssid"
+    help
+	SSID (network name) for the example to connect to.
+
+config ESP_WIFI_PASSWORD
+    string "WiFi Password"
+    default "mypassword"
+    help
+	WiFi password (WPA or WPA2) for the example to use.
+
+config EXAMPLE_PORT
+    string "asio example port number"
+    default "80"
+    help
+    Port number used by ASIO example
+
+endmenu

examples/protocols/asio/chat_server/main/chat_message.hpp

@@ -0,0 +1,91 @@
+//
+// chat_message.hpp
+// ~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef CHAT_MESSAGE_HPP
+#define CHAT_MESSAGE_HPP
+
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+
+class chat_message
+{
+public:
+  enum { header_length = 4 };
+  enum { max_body_length = 512 };
+
+  chat_message()
+    : body_length_(0)
+  {
+  }
+
+  const char* data() const
+  {
+    return data_;
+  }
+
+  char* data()
+  {
+    return data_;
+  }
+
+  std::size_t length() const
+  {
+    return header_length + body_length_;
+  }
+
+  const char* body() const
+  {
+    return data_ + header_length;
+  }
+
+  char* body()
+  {
+    return data_ + header_length;
+  }
+
+  std::size_t body_length() const
+  {
+    return body_length_;
+  }
+
+  void body_length(std::size_t new_length)
+  {
+    body_length_ = new_length;
+    if (body_length_ > max_body_length)
+      body_length_ = max_body_length;
+  }
+
+  bool decode_header()
+  {
+    char header[header_length + 1] = "";
+    std::strncat(header, data_, header_length);
+    body_length_ = std::atoi(header);
+    if (body_length_ > max_body_length)
+    {
+      body_length_ = 0;
+      return false;
+    }
+    return true;
+  }
+
+  void encode_header()
+  {
+    char header[header_length + 1] = "";
+    std::sprintf(header, "%4d", static_cast<int>(body_length_));
+    std::memcpy(data_, header, header_length);
+  }
+
+private:
+  char data_[header_length + max_body_length];
+  std::size_t body_length_;
+};
+
+#endif // CHAT_MESSAGE_HPP

examples/protocols/asio/chat_server/main/chat_server.cpp

@@ -0,0 +1,214 @@
+//
+// chat_server.cpp
+// ~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#include <cstdlib>
+#include <deque>
+#include <iostream>
+#include <list>
+#include <memory>
+#include <set>
+#include <utility>
+#include "asio.hpp"
+#include "chat_message.hpp"
+
+using asio::ip::tcp;
+
+//----------------------------------------------------------------------
+
+typedef std::deque<chat_message> chat_message_queue;
+
+//----------------------------------------------------------------------
+
+class chat_participant
+{
+public:
+  virtual ~chat_participant() {}
+  virtual void deliver(const chat_message& msg) = 0;
+};
+
+typedef std::shared_ptr<chat_participant> chat_participant_ptr;
+
+//----------------------------------------------------------------------
+
+class chat_room
+{
+public:
+  void join(chat_participant_ptr participant)
+  {
+    participants_.insert(participant);
+    for (auto msg: recent_msgs_)
+      participant->deliver(msg);
+  }
+
+  void leave(chat_participant_ptr participant)
+  {
+    participants_.erase(participant);
+  }
+
+  void deliver(const chat_message& msg)
+  {
+    recent_msgs_.push_back(msg);
+    while (recent_msgs_.size() > max_recent_msgs)
+      recent_msgs_.pop_front();
+
+    for (auto participant: participants_)
+      participant->deliver(msg);
+  }
+
+private:
+  std::set<chat_participant_ptr> participants_;
+  enum { max_recent_msgs = 100 };
+  chat_message_queue recent_msgs_;
+};
+
+//----------------------------------------------------------------------
+
+class chat_session
+  : public chat_participant,
+    public std::enable_shared_from_this<chat_session>
+{
+public:
+  chat_session(tcp::socket socket, chat_room& room)
+    : socket_(std::move(socket)),
+      room_(room)
+  {
+  }
+
+  void start()
+  {
+    room_.join(shared_from_this());
+    do_read_header();
+  }
+
+  void deliver(const chat_message& msg)
+  {
+    bool write_in_progress = !write_msgs_.empty();
+    write_msgs_.push_back(msg);
+    if (!write_in_progress)
+    {
+      do_write();
+    }
+  }
+
+private:
+  void do_read_header()
+  {
+    auto self(shared_from_this());
+    asio::async_read(socket_,
+        asio::buffer(read_msg_.data(), chat_message::header_length),
+        [this, self](std::error_code ec, std::size_t /*length*/)
+        {
+          if (!ec && read_msg_.decode_header())
+          {
+            do_read_body();
+          }
+          else
+          {
+            room_.leave(shared_from_this());
+          }
+        });
+  }
+
+  void do_read_body()
+  {
+    auto self(shared_from_this());
+    asio::async_read(socket_,
+        asio::buffer(read_msg_.body(), read_msg_.body_length()),
+        [this, self](std::error_code ec, std::size_t /*length*/)
+        {
+          if (!ec)
+          {
+            room_.deliver(read_msg_);
+            do_read_header();
+          }
+          else
+          {
+            room_.leave(shared_from_this());
+          }
+        });
+  }
+
+  void do_write()
+  {
+    auto self(shared_from_this());
+    asio::async_write(socket_,
+        asio::buffer(write_msgs_.front().data(),
+          write_msgs_.front().length()),
+        [this, self](std::error_code ec, std::size_t /*length*/)
+        {
+          if (!ec)
+          {
+            write_msgs_.pop_front();
+            if (!write_msgs_.empty())
+            {
+              do_write();
+            }
+          }
+          else
+          {
+            room_.leave(shared_from_this());
+          }
+        });
+  }
+
+  tcp::socket socket_;
+  chat_room& room_;
+  chat_message read_msg_;
+  chat_message_queue write_msgs_;
+};
+
+//----------------------------------------------------------------------
+
+class chat_server
+{
+public:
+  chat_server(asio::io_context& io_context,
+      const tcp::endpoint& endpoint)
+    : acceptor_(io_context, endpoint)
+  {
+    do_accept();
+  }
+
+private:
+  void do_accept()
+  {
+    acceptor_.async_accept(
+        [this](std::error_code ec, tcp::socket socket)
+        {
+          if (!ec)
+          {
+            std::make_shared<chat_session>(std::move(socket), room_)->start();
+          }
+
+          do_accept();
+        });
+  }
+
+  tcp::acceptor acceptor_;
+  chat_room room_;
+};
+
+//----------------------------------------------------------------------
+
+int asio_main()
+{
+    asio::io_context io_context;
+
+    std::list<chat_server> servers;
+
+    {
+      tcp::endpoint endpoint(tcp::v4(), std::atoi(CONFIG_EXAMPLE_PORT));
+      servers.emplace_back(io_context, endpoint);
+    }
+
+    io_context.run();
+
+  return 0;
+}

examples/protocols/asio/chat_server/main/component.mk

@@ -0,0 +1,8 @@
+#
+# Main component makefile.
+#
+# This Makefile can be left empty. By default, it will take the sources in the 
+# src/ directory, compile them and link them into lib(subdirectory_name).a 
+# in the build directory. This behaviour is entirely configurable,
+# please read the ESP-IDF documents if you need to do this.
+#