Keep track of request handling time

Signed-off-by: Leonardo Cecchi <[email protected]>

Author: leonardoce

README.md

@@ -21,6 +21,11 @@ Environment variables are your friends:
 As previously said, a new connection is established per request, without any
 connection pool. Use pgbouncer if you need something like that.
 
+## Docker image
+
+A simple Docker image containing this utility can be found at
+[hub.docker.com/r/leonardoce/webtest](https://hub.docker.com/r/leonardoce/webtest).
+
 ## Thanks
 
 https://github.com/yhirose/cpp-httplib is a great tool, really.

http_test.cpp

@@ -12,7 +12,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  **/
- 
+
 #include "httplib.h"
 #include <chrono>
 #include <ctime>
@@ -41,17 +41,38 @@ int main() {
 
   // Starting HTTP server
   httplib::Server svr;
-  svr.set_logger(logger);
   svr.Get("/tx", tx);
   svr.listen("0.0.0.0", 8080);
 
   return 0;
 }
 
 /**
- * Given a request/response pair, put a small log message in stdout
+ * This is a context class that to be used inside a request handler. It will
+ * log the request handling time
+ */
+struct RequestHandlerLogger {
+  const httplib::Request &_request;
+  const httplib::Response &_response;
+
+  const std::chrono::system_clock::time_point _startTime;
+
+  RequestHandlerLogger(const httplib::Request &req,
+                       const httplib::Response &res);
+  ~RequestHandlerLogger();
+};
+
+/**
+ * Start a context, keeping track of when the request started
  */
-void logger(const httplib::Request &req, const httplib::Response &res) {
+RequestHandlerLogger::RequestHandlerLogger(const httplib::Request &req,
+                                           const httplib::Response &res)
+    : _request(req), _response(res), _startTime(std::chrono::system_clock::now()) {}
+
+/**
+ * Stop the context, emitting a log message
+ */
+RequestHandlerLogger::~RequestHandlerLogger() {
   using namespace std;
 
   const auto now = std::chrono::system_clock::now();
@@ -60,17 +81,22 @@ void logger(const httplib::Request &req, const httplib::Response &res) {
                          now.time_since_epoch()) %
                      1000;
 
+  const auto timeOccurred =
+      std::chrono::duration_cast<std::chrono::milliseconds>(now - _startTime) %
+      1000;
+
   cout << std::put_time(std::localtime(&nowAsTimeT), "%a %b %d %Y %T") << '.'
-       << std::setfill('0') << std::setw(3) << nowMs.count();
-  cout << " " << req.remote_addr << " " << req.path << " - " << res.status
-       << endl;
+       << std::setfill('0') << std::setw(3) << nowMs.count() << " "
+       << _request.remote_addr << " " << _request.path << " - " << _response.status << " - "
+       << timeOccurred.count() << "ms" << endl;
   cout.flush();
 }
 
 /**
  * The test transaction on PostgreSQL
  */
 void tx(const httplib::Request &req, httplib::Response &res) {
+  RequestHandlerLogger _logger(req, res);
   PGconn *conn = PQconnectdb(database_url.c_str());
 
   if (PQstatus(conn) != CONNECTION_OK) {
@@ -87,6 +113,7 @@ void tx(const httplib::Request &req, httplib::Response &res) {
       std::cout << PQresultErrorMessage(pgres) << std::endl;
       std::cout.flush();
     } else {
+      res.status = 200;
       res.set_content("Ok!", "text/plain");
     }
     PQclear(pgres);