asio: initial idf port of asio library without ssl

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

examples/protocols/asio/chat_client/main/chat_client.cpp

@@ -0,0 +1,165 @@
+//
+// chat_client.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 <thread>
+#include "asio.hpp"
+#include "chat_message.hpp"
+
+using asio::ip::tcp;
+
+typedef std::deque<chat_message> chat_message_queue;
+
+class chat_client
+{
+public:
+  chat_client(asio::io_context& io_context,
+      const tcp::resolver::results_type& endpoints)
+    : io_context_(io_context),
+      socket_(io_context)
+  {
+    do_connect(endpoints);
+  }
+
+  void write(const chat_message& msg)
+  {
+    asio::post(io_context_,
+        [this, msg]()
+        {
+          bool write_in_progress = !write_msgs_.empty();
+          write_msgs_.push_back(msg);
+          if (!write_in_progress)
+          {
+            do_write();
+          }
+        });
+  }
+
+  void close()
+  {
+    asio::post(io_context_, [this]() { socket_.close(); });
+  }
+
+private:
+  void do_connect(const tcp::resolver::results_type& endpoints)
+  {
+    asio::async_connect(socket_, endpoints,
+        [this](std::error_code ec, tcp::endpoint)
+        {
+          if (!ec)
+          {
+            do_read_header();
+          }
+        });
+  }
+
+  void do_read_header()
+  {
+    asio::async_read(socket_,
+        asio::buffer(read_msg_.data(), chat_message::header_length),
+        [this](std::error_code ec, std::size_t /*length*/)
+        {
+          if (!ec && read_msg_.decode_header())
+          {
+            do_read_body();
+          }
+          else
+          {
+            socket_.close();
+          }
+        });
+  }
+
+  void do_read_body()
+  {
+    asio::async_read(socket_,
+        asio::buffer(read_msg_.body(), read_msg_.body_length()),
+        [this](std::error_code ec, std::size_t /*length*/)
+        {
+          if (!ec)
+          {
+            std::cout.write(read_msg_.body(), read_msg_.body_length());
+            std::cout << "\n";
+            do_read_header();
+          }
+          else
+          {
+            socket_.close();
+          }
+        });
+  }
+
+  void do_write()
+  {
+    asio::async_write(socket_,
+        asio::buffer(write_msgs_.front().data(),
+          write_msgs_.front().length()),
+        [this](std::error_code ec, std::size_t /*length*/)
+        {
+          if (!ec)
+          {
+            write_msgs_.pop_front();
+            if (!write_msgs_.empty())
+            {
+              do_write();
+            }
+          }
+          else
+          {
+            socket_.close();
+          }
+        });
+  }
+
+private:
+  asio::io_context& io_context_;
+  tcp::socket socket_;
+  chat_message read_msg_;
+  chat_message_queue write_msgs_;
+};
+
+void read_line(char * line, int max_chars);
+
+
+void asio_main()
+{
+    std::string name(CONFIG_EXAMPLE_SERVER_IP);
+    std::string port(CONFIG_EXAMPLE_PORT);
+    char line[chat_message::max_body_length + 1] = { 0 };
+
+    if (name == "FROM_STDIN") {
+      std::cout << "Please enter ip address of chat server" << std::endl;
+      if (std::cin.getline(line, chat_message::max_body_length + 1)) {
+        name = line;
+        std::cout << "Chat server IP:" << name << std::endl;
+      }
+    }
+
+    asio::io_context io_context;
+    tcp::resolver resolver(io_context);
+    auto endpoints = resolver.resolve(name, port);
+
+    chat_client c(io_context, endpoints);
+
+    std::thread t([&io_context](){ io_context.run(); });
+
+    while (std::cin.getline(line, chat_message::max_body_length + 1) && std::string(line) != "exit\n") {
+      chat_message msg;
+      msg.body_length(std::strlen(line));
+      std::memcpy(msg.body(), line, msg.body_length());
+      msg.encode_header();
+      c.write(msg);
+    }
+
+    c.close();
+    t.join();
+}