//
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//
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// Lab. Calcolo II - Esempio di codice
//
//
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// <![CDATA[
// Example code: Boost::asio HTTP client example code.
// (20160829 francesco.prelz@mi.infn.it)
#include <iostream>
#include <memory>
#include <string>
#include <sstream>
#include <functional>
#include <boost/asio.hpp>
#include "TApplication.h"
#include "TASImage.h"
typedef boost::asio::buffers_iterator<boost::asio::streambuf::const_buffers_type> stbuf_it;
int
main(int argc, char *argv[])
{
if (argc < 2)
{
std::cerr << "Usage: " << argv[0] << " <HTTP server name> [service/port]" << std::endl;
return 1;
}
std::string service("http");
if (argc > 2) service = argv[2];
TApplication theApp("Async I/O Example", &argc, argv);
boost::asio::io_service io_service;
using boost::asio::ip::tcp;
tcp::resolver resolver(io_service);
tcp::resolver::query query(argv[1], service);
tcp::socket socket(io_service);
boost::asio::streambuf buffer;
TASImage image;
resolver.async_resolve(query, [&](const boost::system::error_code& error,
tcp::resolver::iterator iterator)
{
if (error)
{
std::cerr << "Error from boost::asio::ip::tcp::resolver::async_resolve: "
<< error.message() << std::endl;
exit(1);
}
else
{
tcp::resolver::iterator end;
boost::asio::async_connect(socket, iterator, end,
[&](const boost::system::error_code& error,
tcp::resolver::iterator iterator)
{
if (error)
{
std::cerr << "Error from boost::asio::ip::tcp::socket:async_connect: "
<< error.message() << std::endl;
exit(1);
}
else
{
std::string msg("GET /\r\n");
socket.send(boost::asio::buffer(msg,msg.length()));
boost::asio::async_read_until(socket, buffer,
// Need to create a std::function here as the 'MatchCondition'
// argument to async_read_until is tested via
// boost::asio::is_function<T> in struct
// boost::asio::is_match_condition, and this returns false on
// closures as of boost v1_55.
std::function<std::pair<stbuf_it, bool>(stbuf_it begin, stbuf_it end)> (
[&socket] (stbuf_it begin, stbuf_it end)
{
bool result = socket.is_open();
return std::make_pair(end, !result);
}),
[&](const boost::system::error_code& error,
std::size_t size)
{
// Do something with the data
std::istream is(&buffer);
std::string s;
while (is)
{
std::getline(is,s);
if (s.find("Content-Type: image/png") == 0)
{
// Discard CRLF after Content-Type.
std::getline(is,s);
int img_size = boost::asio::buffer_size(buffer.data());
// C++14: auto img_data = std::make_unique<unsigned char[]>(img_size);
char img_data[img_size];
is.read(img_data, img_size);
char *img_start = &(img_data[0]);
image.SetImageBuffer(&img_start, TImage::kPng);
image.Draw();
}
}
}
);
}
}
);
}
}
);
io_service.run();
std::cout << "*** Exit the program by selecting Quit from the File menu ***"
<< std::endl;
theApp.Run(kTRUE);
return 0;
}
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