Add timeout control to http server (draft)

CMakeLists.txt

@@ -65,7 +65,12 @@ find_package(Threads REQUIRED)
 # Boost version: 1.66+
 set(Boost_USE_STATIC_LIBS ON)
 set(Boost_USE_MULTITHREADED ON)
-find_package(Boost 1.66.0 REQUIRED COMPONENTS system thread)
+if(WIN32)
+	# TODO: Fix COMPONENTS on Windows.
+	find_package(Boost 1.66.0 REQUIRED)
+else()
+	find_package(Boost 1.66.0 REQUIRED COMPONENTS system thread)
+endif()
 if(Boost_FOUND)
     include_directories(${Boost_INCLUDE_DIRS})
     link_directories(${Boost_LIBRARY_DIRS})

src/demo/rest/book_client/book_client.cc

@@ -1,2 +0,0 @@
-#include "book_client.h"
-

src/demo/rest/book_client/book_client.h

@@ -1,6 +0,0 @@
-#ifndef BOOK_CLIENT_H_
-#define BOOK_CLIENT_H_
-
-#include <string>
-
-#endif  // BOOK_CLIENT_H_

src/demo/rest/book_client/main.cc

@@ -1,5 +1,4 @@
 #include <iostream>
-#include "boost/lexical_cast.hpp"
 
 #include "webcc/http_client.h"
 #include "webcc/http_request.h"

src/demo/rest/book_server/book_services.cc

@@ -1,7 +1,10 @@
 #include "book_services.h"
 
 #include <list>
+
 #include "boost/lexical_cast.hpp"
+#include "boost/thread.hpp"
+#include "boost/date_time/posix_time/posix_time.hpp"
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -21,6 +24,7 @@ static const Book kNullBook{};
 class BookStore {
 public:
   BookStore() {
+    // Prepare test data.
     books_.push_back({ "1", "Title1", 11.1 });
     books_.push_back({ "2", "Title2", 22.2 });
     books_.push_back({ "3", "Title3", 33.3 });
@@ -77,8 +81,8 @@ static BookStore g_book_store;
 
 ////////////////////////////////////////////////////////////////////////////////
 
-// Naively create JSON object string for a book.
-// You should use real JSON library in your product code.
+// Naively create JSON object for a book.
+// You should use real JSON library in real product.
 static std::string CreateBookJson(const Book& book) {
   std::string json = "{ ";
   json += "\"id\": " + book.id + ", ";
@@ -88,17 +92,36 @@ static std::string CreateBookJson(const Book& book) {
   return json;
 }
 
+// Naively create JSON array object for a list of books.
+// You should use real JSON library in real product.
+static std::string CreateBookListJson(const std::list<Book>& books) {
+  std::string json = "[ ";
+
+  for (const Book& book : books) {
+    json += CreateBookJson(book);
+    json += ",";
+  }
+
+  // Remove last ','.
+  if (!books.empty()) {
+    json[json.size() - 1] = ' ';
+  }
+
+  json += "]";
+
+  return json;
+}
+
 bool BookListService::Handle(const std::string& http_method,
                              const std::vector<std::string>& url_sub_matches,
                              const std::string& request_content,
                              std::string* response_content) {
   if (http_method == webcc::kHttpGet) {
-    *response_content = "{ ";
-    for (const Book& book : g_book_store.books()) {
-      *response_content += CreateBookJson(book);
-      *response_content += ",";
-    }
-    *response_content += " }";
+    *response_content = CreateBookListJson(g_book_store.books());
+
+    // Sleep for testing timeout control.
+    boost::this_thread::sleep(boost::posix_time::seconds(2));
+
     return true;
   }
 
@@ -126,6 +149,9 @@ bool BookDetailService::Handle(const std::string& http_method,
 
     *response_content = CreateBookJson(book);
 
+    // Sleep for testing timeout control.
+    //boost::this_thread::sleep(boost::posix_time::seconds(2));
+
     return true;
 
   } else if (http_method == webcc::kHttpPost) {

src/demo/rest/book_server/main.cc

@@ -27,6 +27,11 @@ int main(int argc, char* argv[]) {
     server.RegisterService(std::make_shared<BookDetailService>(),
                            "/books/(\\d+)");
 
+    // For test purpose.
+    // Timeout like 60s makes more sense in a real product.
+    // Leave it as default (0) for no timeout control.
+    server.set_timeout_seconds(1);
+
     server.Run();
 
   } catch (std::exception& e) {

src/webcc/http_server.cc

@@ -16,7 +16,8 @@ namespace webcc {
 
 HttpServer::HttpServer(unsigned short port, std::size_t workers)
     : signals_(io_context_)
-    , workers_(workers) {
+    , workers_(workers)
+    , timeout_seconds_(0) {
 
   // Register to handle the signals that indicate when the server should exit.
   // It is safe to register for the same signal multiple times in a program,
@@ -47,7 +48,7 @@ HttpServer::~HttpServer() {
 }
 
 void HttpServer::Run() {
-  assert(request_handler_ != NULL);
+  assert(GetRequestHandler() != NULL);
 
 #if WEBCC_DEBUG_OUTPUT
   boost::thread::id thread_id = boost::this_thread::get_id();
@@ -55,7 +56,7 @@ void HttpServer::Run() {
 #endif
 
   // Start worker threads.
-  request_handler_->Start(workers_);
+  GetRequestHandler()->Start(workers_);
 
   // The io_context::run() call will block until all asynchronous operations
   // have finished. While the server is running, there is always at least one
@@ -74,10 +75,10 @@ void HttpServer::DoAccept() {
         }
 
         if (!ec) {
-          HttpSessionPtr conn{
-            new HttpSession(std::move(socket), request_handler_)
+          HttpSessionPtr session{
+            new HttpSession(std::move(socket), GetRequestHandler())
           };
-          conn->Start();
+          session->Start(timeout_seconds_);
         }
 
         DoAccept();
@@ -91,7 +92,7 @@ void HttpServer::DoAwaitStop() {
         // operations. Once all operations have finished the io_context::run()
         // call will exit.
         acceptor_->close();
-        request_handler_->Stop();
+        GetRequestHandler()->Stop();
       });
 }
 

src/webcc/http_server.h

@@ -28,6 +28,10 @@ public:
 
   virtual ~HttpServer();
 
+  void set_timeout_seconds(long seconds) {
+    timeout_seconds_ = seconds;
+  }
+
   // Run the server's io_service loop.
   void Run();
 
@@ -38,10 +42,8 @@ private:
   // Wait for a request to stop the server.
   void DoAwaitStop();
 
-protected:
-  // The handler for all incoming requests.
-  // TODO: Replace with virtual GetRequestHandler()?
-  HttpRequestHandler* request_handler_;
+  // Get the handler for incoming requests.
+  virtual HttpRequestHandler* GetRequestHandler() = 0;
 
 private:
   // The number of worker threads.
@@ -55,6 +57,10 @@ private:
 
   // Acceptor used to listen for incoming connections.
   boost::scoped_ptr<boost::asio::ip::tcp::acceptor> acceptor_;
+
+  // Timeout in seconds for socket connection.
+  // Default is 0 which means no timeout.
+  long timeout_seconds_;
 };
 
 }  // namespace webcc

src/webcc/http_session.cc

@@ -6,6 +6,7 @@
 #endif
 
 #include "boost/asio/write.hpp"
+#include "boost/date_time/posix_time/posix_time.hpp"
 
 #include "webcc/http_request_handler.h"
 
@@ -18,12 +19,30 @@ HttpSession::HttpSession(boost::asio::ip::tcp::socket socket,
     , request_parser_(&request_) {
 }
 
-void HttpSession::Start() {
+HttpSession::~HttpSession() {
+}
+
+void HttpSession::Start(long timeout_seconds) {
+  if (timeout_seconds > 0) {
+    // Create timer only necessary.
+    boost::asio::io_context& ioc = socket_.get_executor().context();
+    timer_.reset(new boost::asio::deadline_timer(ioc));
+
+    timer_->expires_from_now(boost::posix_time::seconds(timeout_seconds));
+
+    timer_->async_wait(std::bind(&HttpSession::HandleTimer,
+                                 shared_from_this(),
+                                 std::placeholders::_1));
+  }
+  
   DoRead();
 }
 
 void HttpSession::Stop() {
-  socket_.close();
+  CancelTimer();
+
+  boost::system::error_code ignored_ec;
+  socket_.close(ignored_ec);
 }
 
 void HttpSession::SetResponseContent(const std::string& content_type,
@@ -59,6 +78,8 @@ void HttpSession::HandleRead(boost::system::error_code ec,
   if (ec) {
     if (ec != boost::asio::error::operation_aborted) {
       Stop();
+    } else {
+      CancelTimer();
     }
     return;
   }
@@ -89,21 +110,59 @@ void HttpSession::HandleRead(boost::system::error_code ec,
 // io_context.run), even though DoWrite() is invoked by worker threads. This is
 // ensured by Asio.
 void HttpSession::HandleWrite(boost::system::error_code ec,
-                              size_t length) {
+                              std::size_t length) {
 #if WEBCC_DEBUG_OUTPUT
   boost::thread::id thread_id = boost::this_thread::get_id();
-  std::cout << "Response has been sent back (thread: " << thread_id << ")\n";
 #endif
 
   if (!ec) {
+    CancelTimer();
+
     // Initiate graceful connection closure.
-    boost::system::error_code ignored_ec;
-    socket_.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ignored_ec);
-  }
+    boost::system::error_code ec;
+    socket_.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);
 
-  if (ec != boost::asio::error::operation_aborted) {
+#if WEBCC_DEBUG_OUTPUT
+    std::cout << "Response has been sent back (thread: " << thread_id << ")\n";
+#endif
+  } else {
+#if WEBCC_DEBUG_OUTPUT
+    std::cout << "(thread: " << thread_id << ") Sending response error: "
+      << ec.message()
+      << std::endl;
+#endif
+
+    if (ec == boost::asio::error::operation_aborted) {
+      CancelTimer();
+    } else {
       Stop();
     }
+  }
+}
+
+void HttpSession::HandleTimer(boost::system::error_code ec) {
+  std::cout << "HandleTimer: ";
+
+  if (!ec) {
+    if (socket_.is_open()) {
+      std::cout << "socket is open, close it.\n";
+      socket_.close();
+    } else {
+      std::cout << "socket is not open.\n";
+    }
+  } else {
+    if (ec == boost::asio::error::operation_aborted) {
+      std::cout << "Timer aborted\n";
+    }
+  }
+}
+
+void HttpSession::CancelTimer() {
+  if (timer_) {
+    // The wait handler will be invoked with the operation_aborted error code.
+    boost::system::error_code ec;
+    timer_->cancel(ec);
+  }
 }
 
 }  // namespace webcc

src/webcc/http_session.h

@@ -5,6 +5,7 @@
 #include <memory>
 
 #include "boost/asio/ip/tcp.hpp"  // for ip::tcp::socket
+#include "boost/asio/deadline_timer.hpp"
 
 #include "webcc/common.h"
 #include "webcc/http_request.h"
@@ -17,19 +18,20 @@ class HttpRequestHandler;
 
 class HttpSession : public std::enable_shared_from_this<HttpSession> {
 public:
-  friend class HttpRequestHandler;
-
   HttpSession(const HttpSession&) = delete;
   HttpSession& operator=(const HttpSession&) = delete;
 
   HttpSession(boost::asio::ip::tcp::socket socket,
               HttpRequestHandler* handler);
 
+  ~HttpSession();
+
   const HttpRequest& request() const {
     return request_;
   }
 
-  void Start();
+  // Start the session with an optional timeout.
+  void Start(long timeout_seconds = 0);
 
   void Stop();
 
@@ -49,16 +51,20 @@ private:
 
   void DoWrite();
 
-  void HandleRead(boost::system::error_code ec,
-                  std::size_t length);
+  void HandleRead(boost::system::error_code ec, std::size_t length);
+  void HandleWrite(boost::system::error_code ec, std::size_t length);
 
-  void HandleWrite(boost::system::error_code ec,
-                   std::size_t length);
+  void HandleTimer(boost::system::error_code ec);
+
+  void CancelTimer();
 
 private:
   // Socket for the connection.
   boost::asio::ip::tcp::socket socket_;
 
+  // Timeout timer (optional).
+  std::unique_ptr<boost::asio::deadline_timer> timer_;
+
   // The handler used to process the incoming request.
   HttpRequestHandler* request_handler_;
 

src/webcc/rest_server.cc

@@ -104,18 +104,16 @@ HttpStatus::Enum RestRequestHandler::HandleSession(HttpSessionPtr session) {
 
 RestServer::RestServer(unsigned short port, std::size_t workers)
     : HttpServer(port, workers)
-    , rest_request_handler_(new RestRequestHandler()) {
-  request_handler_ = rest_request_handler_;
+    , request_handler_(new RestRequestHandler()) {
 }
 
 RestServer::~RestServer() {
-  request_handler_ = NULL;
-  delete rest_request_handler_;
+  delete request_handler_;
 }
 
 bool RestServer::RegisterService(RestServicePtr service,
                                  const std::string& url) {
-  return rest_request_handler_->RegisterService(service, url);
+  return request_handler_->RegisterService(service, url);
 }
 
 }  // namespace webcc

src/webcc/rest_server.h

@@ -97,7 +97,12 @@ public:
   bool RegisterService(RestServicePtr service, const std::string& url);
 
 private:
-  RestRequestHandler* rest_request_handler_;
+  HttpRequestHandler* GetRequestHandler() override {
+    return request_handler_;
+  }
+
+private:
+  RestRequestHandler* request_handler_;
 };
 
 }  // namespace webcc

src/webcc/soap_server.cc

@@ -72,18 +72,16 @@ SoapServicePtr SoapRequestHandler::GetServiceByUrl(const std::string& url) {
 
 SoapServer::SoapServer(unsigned short port, std::size_t workers)
     : HttpServer(port, workers)
-    , soap_request_handler_(new SoapRequestHandler()) {
-  request_handler_ = soap_request_handler_;
+    , request_handler_(new SoapRequestHandler()) {
 }
 
 SoapServer::~SoapServer() {
-  request_handler_ = NULL;
-  delete soap_request_handler_;
+  delete request_handler_;
 }
 
 bool SoapServer::RegisterService(SoapServicePtr service,
                                  const std::string& url) {
-  return soap_request_handler_->RegisterService(service, url);
+  return request_handler_->RegisterService(service, url);
 }
 
 }  // namespace webcc

src/webcc/soap_server.h

@@ -44,7 +44,12 @@ public:
   bool RegisterService(SoapServicePtr service, const std::string& url);
 
 private:
-  SoapRequestHandler* soap_request_handler_;
+  HttpRequestHandler* GetRequestHandler() override {
+    return request_handler_;
+  }
+
+private:
+  SoapRequestHandler* request_handler_;
 };
 
 }  // namespace webcc