example: send response content-length as part of http header from server to client (issue #681)

carun · deanberris · commit e653e47c7225 · 2018-01-26T14:02:17.000+11:00
diff --git a/libs/network/example/http/async_server_file_upload.cpp b/libs/network/example/http/async_server_file_upload.cpp
@@ -191,6 +191,7 @@ struct connection_handler {
     void operator()(server::request const& req, const server::connection_ptr& conn) {
         static std::map<std::string, std::string> headers = {
             {"Connection","close"},
+            {"Content-Length", "0"},
             {"Content-Type", "text/plain"}
         };
 
@@ -206,24 +207,29 @@ struct connection_handler {
                 // Wait until the data transfer is done by the IO threads
                 uploader->wait_for_completion();
 
-                // Respond to the client
-                conn->set_status(server::connection::ok);
-                conn->set_headers(headers);
                 auto end = std::chrono::high_resolution_clock::now();
                 std::chrono::duration<double, std::milli> diff = end - start;
                 std::ostringstream stm;
                 stm << "Took " << diff.count() << " milliseconds for the transfer." << std::endl;
-                conn->write(stm.str());
+                auto body = stm.str();
+                // Respond to the client
+                headers["Content-Length"] = std::to_string(body.size());
+                conn->set_status(server::connection::ok);
+                conn->set_headers(headers);
+                conn->write(body);
             } catch (const file_uploader_exception& e) {
+                const std::string err = e.what();
+                headers["Content-Length"] = std::to_string(err.size());
                 conn->set_status(server::connection::bad_request);
                 conn->set_headers(headers);
-                const std::string err = e.what();
                 conn->write(err);
             }
         } else {
+            static std::string body("Only path allowed is /upload");
+            headers["Content-Length"] = std::to_string(body.size());
             conn->set_status(server::connection::bad_request);
             conn->set_headers(headers);
-            conn->write("Only path allowed is /upload.");
+            conn->write(body);
         }
     }
 };
diff --git a/libs/network/example/http/hello_world_async_server_with_work_queue.cpp b/libs/network/example/http/hello_world_async_server_with_work_queue.cpp
@@ -125,13 +125,16 @@ void process_request(work_queue& queue) {
       // some heavy work!
       std::this_thread::sleep_for(std::chrono::seconds(10));
 
-      std::map<std::string, std::string> headers = {
+      static std::map<std::string, std::string> headers = {
+        {"Content-Length", "0"},
         {"Content-Type", "text/plain"},
       };
 
+      std::string body("Hello, world!");
+      headers["Content-Length"] = std::to_string(body.size());
       request->conn->set_status(server::connection::ok);
       request->conn->set_headers(headers);
-      request->conn->write("Hello, world!");
+      request->conn->write(body);
     }
 
     std::this_thread::sleep_for(std::chrono::microseconds(1000));
diff --git a/libs/network/example/http/hello_world_server.cpp b/libs/network/example/http/hello_world_server.cpp
@@ -30,13 +30,17 @@ struct hello_world {
     std::ostringstream data;
     data << "Hello, " << ip << ':' << port << '!';
 
-    std::map<std::string, std::string> headers = {
+    static std::map<std::string, std::string> headers = {
+      {"Content-Length", "0"},
       {"Content-Type", "text/plain"},
     };
 
+    auto body = data.str();
+    headers["Content-Length"] = std::to_string(body.size());
+
     connection->set_status(server::connection::ok);
     connection->set_headers(headers);
-    connection->write(data.str());
+    connection->write(body);
   }
 };
 
