adding factory function probing_port_range()

test_webserver.cc

@@ -5,11 +5,19 @@
 
 int main()
 {
-    std::cout << "serving http://127.0.0.1:8080/test.html\n";
-    pEp::Webserver web{pEp::net::ip::address::from_string("127.0.0.1"), 8080, "htdocs"};
-
-    std::cout << "adding handler for http://127.0.0.1:8080/handler/sample\n";
-    web.add_url_handler("/handler/(?<name>\\w+)",
+    unsigned short port;
+    auto web =
+        pEp::Webserver::probing_port_range(pEp::net::ip::address::from_string("127.0.0.1"),
+                8080, 8089, port, "htdocs");
+    if (!web) {
+        std::cerr << "cannot start webserver, no ports free\n";
+        return 1;
+    }
+
+    std::cout << "serving http://127.0.0.1:" << port << "/test.html\n";
+
+    std::cout << "adding handler for http://127.0.0.1:" << port << "/handler/sample\n";
+    web->add_url_handler("/handler/(?<name>\\w+)",
         [](boost::cmatch m, const pEp::Webserver::request& req)->pEp::Webserver::response {
             auto res = pEp::Webserver::response{pEp::http::status::ok, req.version()};
 
@@ -41,7 +49,8 @@ int main()
         }
     );
 
-    web.run();
+    web->run();
+    delete web;
 
     return 0;
 }

webserver.cc

@@ -22,35 +22,6 @@ namespace pEp {
     , _running{false}
     { }
 
-
-Webserver::Webserver(net::ip::address addr, unsigned short start_port, unsigned short end_port)
-: _ioc{1}
-, _acceptor{_ioc}
-, _doc_root{} // no doc_root
-, _generic_handler{}
-, _port{-1}
-, _running{false}
-{
-    boost::system::error_code ec{};
-
-    for(unsigned short port = start_port; port<=end_port; ++port)
-    {
-        _acceptor.bind( {addr, port }, ec );
-        if(!ec)
-        {
-            _port = port;
-            break;
-        }
-    }
-    
-    if(_port<0)
-    {
-        throw boost::system::system_error(ec, "Cannot bind to any port from "
-            + std::to_string(start_port) + " to " + std::to_string(end_port) + ".");
-    }
-}
-
-
 beast::string_view Webserver::mime_type(beast::string_view path)
 {
     using beast::iequals;
@@ -122,6 +93,23 @@ Webserver::response Webserver::create_status_response(const request& req, http::
     return res;
 }
 
+Webserver* Webserver::probing_port_range(net::ip::address addr, unsigned short
+        start, unsigned short end, unsigned short& port, const std::string&
+        doc_root)
+{
+    pEp::Webserver *web = nullptr;
+
+    for (port = start; port <= end; ++port) {
+        try {
+            web = new pEp::Webserver{addr, port, doc_root};
+            break;
+        }
+        catch (boost::system::system_error& err) {
+        }
+    }
+
+    return web;
+}
 
 void Webserver::deliver_status(tcp::socket *socket, const request& req, http::status status)
 {

webserver.hh

@@ -43,7 +43,7 @@ namespace pEp {
             std::string _doc_root;
             std::unordered_map< std::string, Handling > _urls;
             handler_t _generic_handler;
-            int  _port;
+            unsigned short _port;
             bool _running;
             std::mutex _mtx;
 
@@ -52,9 +52,6 @@ namespace pEp {
             // if doc_root is empty, don't deliver arbitrary files.
             Webserver(net::ip::address addr, unsigned short port, const std::string& doc_root = "");
 
-            // probes all ports from start_port ... end_port, inclusive.
-            Webserver(net::ip::address addr, unsigned short start_port, unsigned short end_port);
-
             Webserver(const Webserver&) = delete;
             Webserver& operator=(const Webserver&) = delete;
             virtual ~Webserver() = default;
@@ -77,6 +74,10 @@ namespace pEp {
             static
             response create_status_response(const request& req, http::status status);
 
+            static Webserver* probing_port_range(net::ip::address addr,
+                    unsigned short start, unsigned short end, unsigned short&
+                    port, const std::string& doc_root = "");
+
         protected:
             void deliver_status(tcp::socket *socket, const request& req, http::status status);
             void deliver_file  (tcp::socket *socket, const request& req);