http_examples.cpp

#include "client_http.hpp"
#include "server_http.hpp"
#include <future>

// Added for the json-example
#define BOOST_SPIRIT_THREADSAFE
#include <boost/property_tree/json_parser.hpp>
#include <boost/property_tree/ptree.hpp>

// Added for the default_resource example
#include <algorithm>
#include <boost/filesystem.hpp>
#include <fstream>
#include <vector>
#ifdef HAVE_OPENSSL
#include "crypto.hpp"
#endif

using namespace std;
// Added for the json-example:
using namespace boost::property_tree;

using HttpServer = SimpleWeb::Server<SimpleWeb::HTTP>;
using HttpClient = SimpleWeb::Client<SimpleWeb::HTTP>;

int main() {
  // HTTP-server at port 8080 using 1 thread
  // Unless you do more heavy non-threaded processing in the resources,
  // 1 thread is usually faster than several threads
  HttpServer server;
  server.config.port = 8080;

  // Add resources using path-regex and method-string, and an anonymous function
  // POST-example for the path /string, responds the posted string
  server.resource["^/string$"]["POST"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
    // Retrieve string:
    auto content = request->content.string();
    // request->content.string() is a convenience function for:
    // stringstream ss;
    // ss << request->content.rdbuf();
    // auto content=ss.str();

    *response << "HTTP/1.1 200 OK\r\nContent-Length: " << content.length() << "\r\n\r\n"
              << content;


    // Alternatively, use one of the convenience functions, for instance:
    // response->write(content);
  };

  // POST-example for the path /json, responds firstName+" "+lastName from the posted json
  // Responds with an appropriate error message if the posted json is not valid, or if firstName or lastName is missing
  // Example posted json:
  // {
  //   "firstName": "John",
  //   "lastName": "Smith",
  //   "age": 25
  // }
  server.resource["^/json$"]["POST"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
    try {
      ptree pt;
      read_json(request->content, pt);

      auto name = pt.get<string>("firstName") + " " + pt.get<string>("lastName");

      *response << "HTTP/1.1 200 OK\r\n"
                << "Content-Length: " << name.length() << "\r\n\r\n"
                << name;
    }
    catch(const exception &e) {
      *response << "HTTP/1.1 400 Bad Request\r\nContent-Length: " << strlen(e.what()) << "\r\n\r\n"
                << e.what();
    }


    // Alternatively, using a convenience function:
    // try {
    //     ptree pt;
    //     read_json(request->content, pt);

    //     auto name=pt.get<string>("firstName")+" "+pt.get<string>("lastName");
    //     response->write(name);
    // }
    // catch(const exception &e) {
    //     response->write(SimpleWeb::StatusCode::client_error_bad_request, e.what());
    // }
  };

  // GET-example for the path /info
  // Responds with request-information
  server.resource["^/info$"]["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
    stringstream stream;
    stream << "<h1>Request from " << request->remote_endpoint().address().to_string() << ":" << request->remote_endpoint().port() << "</h1>";

    stream << request->method << " " << request->path << " HTTP/" << request->http_version;

    stream << "<h2>Query Fields</h2>";
    auto query_fields = request->parse_query_string();
    for(auto &field : query_fields)
      stream << field.first << ": " << field.second << "<br>";

    stream << "<h2>Header Fields</h2>";
    for(auto &field : request->header)
      stream << field.first << ": " << field.second << "<br>";

    response->write(stream);
  };

  // GET-example for the path /match/[number], responds with the matched string in path (number)
  // For instance a request GET /match/123 will receive: 123
  server.resource["^/match/([0-9]+)$"]["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
    response->write(request->path_match[1].str());
  };

  // GET-example simulating heavy work in a separate thread
  server.resource["^/work$"]["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> /*request*/) {
    thread work_thread([response] {
      this_thread::sleep_for(chrono::seconds(5));
      response->write("Work done");
    });
    work_thread.detach();
  };

  // Default GET-example. If no other matches, this anonymous function will be called.
  // Will respond with content in the web/-directory, and its subdirectories.
  // Default file: index.html
  // Can for instance be used to retrieve an HTML 5 client that uses REST-resources on this server
  server.default_resource["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
    try {
      auto web_root_path = boost::filesystem::canonical("web");
      auto path = boost::filesystem::canonical(web_root_path / request->path);
      // Check if path is within web_root_path
      if(distance(web_root_path.begin(), web_root_path.end()) > distance(path.begin(), path.end()) ||
         !equal(web_root_path.begin(), web_root_path.end(), path.begin()))
        throw invalid_argument("path must be within root path");
      if(boost::filesystem::is_directory(path))
        path /= "index.html";

      SimpleWeb::CaseInsensitiveMultimap header;

      // Uncomment the following line to enable Cache-Control
      // header.emplace("Cache-Control", "max-age=86400");

#ifdef HAVE_OPENSSL
//    Uncomment the following lines to enable ETag
//    {
//      ifstream ifs(path.string(), ifstream::in | ios::binary);
//      if(ifs) {
//        auto hash = SimpleWeb::Crypto::to_hex_string(SimpleWeb::Crypto::md5(ifs));
//        header.emplace("ETag", "\"" + hash + "\"");
//        auto it = request->header.find("If-None-Match");
//        if(it != request->header.end()) {
//          if(!it->second.empty() && it->second.compare(1, hash.size(), hash) == 0) {
//            response->write(SimpleWeb::StatusCode::redirection_not_modified, header);
//            return;
//          }
//        }
//      }
//      else
//        throw invalid_argument("could not read file");
//    }
#endif

      auto ifs = make_shared<ifstream>();
      ifs->open(path.string(), ifstream::in | ios::binary | ios::ate);

      if(*ifs) {
        auto length = ifs->tellg();
        ifs->seekg(0, ios::beg);

        header.emplace("Content-Length", to_string(length));
        response->write(header);

        // Trick to define a recursive function within this scope (for example purposes)
        class FileServer {
        public:
          static void read_and_send(const shared_ptr<HttpServer::Response> &response, const shared_ptr<ifstream> &ifs) {
            // Read and send 128 KB at a time
            static vector<char> buffer(131072); // Safe when server is running on one thread
            streamsize read_length;
            if((read_length = ifs->read(&buffer[0], static_cast<streamsize>(buffer.size())).gcount()) > 0) {
              response->write(&buffer[0], read_length);
              if(read_length == static_cast<streamsize>(buffer.size())) {
                response->send([response, ifs](const SimpleWeb::error_code &ec) {
                  if(!ec)
                    read_and_send(response, ifs);
                  else
                    cerr << "Connection interrupted" << endl;
                });
              }
            }
          }
        };
        FileServer::read_and_send(response, ifs);
      }
      else
        throw invalid_argument("could not read file");
    }
    catch(const exception &e) {
      response->write(SimpleWeb::StatusCode::client_error_bad_request, "Could not open path " + request->path + ": " + e.what());
    }
  };

  server.on_error = [](shared_ptr<HttpServer::Request> /*request*/, const SimpleWeb::error_code & /*ec*/) {
    // Handle errors here
    // Note that connection timeouts will also call this handle with ec set to SimpleWeb::errc::operation_canceled
  };

  // Start server and receive assigned port when server is listening for requests
  promise<unsigned short> server_port;
  thread server_thread([&server, &server_port]() {
    // Start server
    server.start([&server_port](unsigned short port) {
      server_port.set_value(port);
    });
  });
  cout << "Server listening on port " << server_port.get_future().get() << endl << endl;

  // Client examples
  string json_string = "{\"firstName\": \"John\",\"lastName\": \"Smith\",\"age\": 25}";

  // Synchronous request examples
  {
    HttpClient client("localhost:8080");
    try {
      cout << "Example GET request to http://localhost:8080/match/123" << endl;
      auto r1 = client.request("GET", "/match/123");
      cout << "Response content: " << r1->content.rdbuf() << endl << endl; // Alternatively, use the convenience function r1->content.string()

      cout << "Example POST request to http://localhost:8080/string" << endl;
      auto r2 = client.request("POST", "/string", json_string);
      cout << "Response content: " << r2->content.rdbuf() << endl << endl;
    }
    catch(const SimpleWeb::system_error &e) {
      cerr << "Client request error: " << e.what() << endl;
    }
  }

  // Asynchronous request example
  {
    HttpClient client("localhost:8080");
    cout << "Example POST request to http://localhost:8080/json" << endl;
    client.request("POST", "/json", json_string, [](shared_ptr<HttpClient::Response> response, const SimpleWeb::error_code &ec) {
      if(!ec)
        cout << "Response content: " << response->content.rdbuf() << endl;
    });
    client.io_service->run();
  }

  server_thread.join();
}