add logging interface

src/HttpContext.h

@@ -25,9 +25,9 @@
 #include "HttpResponseData.h"
 #include "AsyncSocket.h"
 #include "WebSocketData.h"
+#include "Log.h"
 
 #include <string_view>
-#include <iostream>
 #include "f2/function2.hpp"
 
 namespace uWS {
@@ -144,6 +144,7 @@ struct HttpContext {
 
  /* Are we not ready for another request yet? Terminate the connection. */
  if (httpResponseData->state & HttpResponseData<SSL>::HTTP_RESPONSE_PENDING) {
+ UWS_LOG_REQUEST(3, "terminating connection (HTTP_RESPONSE_PENDING)");
  us_socket_close(SSL, (us_socket_t *) s, 0, nullptr);
  return nullptr;
  }
@@ -155,30 +156,36 @@ struct HttpContext {
  httpContextData->router.getUserData() = {(HttpResponse<SSL> *) s, httpRequest};
  if (!httpContextData->router.route(httpRequest->getMethod(), httpRequest->getUrl())) {
  /* We have to force close this socket as we have no handler for it */
+ UWS_LOG_REQUEST(1, "No handler for route ", httpRequest->getMethod(), " ", httpRequest->getUrl());
  us_socket_close(SSL, (us_socket_t *) s, 0, nullptr);
  return nullptr;
  }
+ else {
+ UWS_LOG_REQUEST(3, "Successfully handled route ", httpRequest->getMethod(), " ", httpRequest->getUrl());
+ }
 
  /* First of all we need to check if this socket was deleted due to upgrade */
  if (httpContextData->upgradedWebSocket) {
  /* We differ between closed and upgraded below */
+ UWS_LOG_REQUEST(3, "socket was deleted due to upgrade");
  return nullptr;
  }
 
  /* Was the socket closed? */
  if (us_socket_is_closed(SSL, (struct us_socket_t *) s)) {
+ UWS_LOG_REQUEST(3, "socket was closed");
  return nullptr;
  }
 
  /* We absolutely have to terminate parsing if shutdown */
  if (us_socket_is_shut_down(SSL, (us_socket_t *) s)) {
+ UWS_LOG_REQUEST(3, "socket was shutdown");
  return nullptr;
  }
 
  /* Returning from a request handler without responding or attaching an onAborted handler is ill-use */
  if (!((HttpResponse<SSL> *) s)->hasResponded() && !httpResponseData->onAborted) {
- /* Throw exception here? */
- std::cerr << "Error: Returning from a request handler without responding or attaching an abort handler is forbidden!" << std::endl;
+ UWS_LOG_REQUEST(0, "Error: Returning from a request handler without responding or attaching an abort handler is forbidden!");
  std::terminate();
  }
 
@@ -208,11 +215,13 @@ struct HttpContext {
 
  /* Was the socket closed? */
  if (us_socket_is_closed(SSL, (struct us_socket_t *) user)) {
+ UWS_LOG_REQUEST(3, "socket was closed");
  return nullptr;
  }
 
  /* We absolutely have to terminate parsing if shutdown */
  if (us_socket_is_shut_down(SSL, (us_socket_t *) user)) {
+ UWS_LOG_REQUEST(3, "socket was shutdown");
  return nullptr;
  }
 
@@ -340,6 +349,7 @@ struct HttpContext {
  httpContext = (HttpContext *) us_create_socket_context(SSL, (us_loop_t *) loop, sizeof(HttpContextData<SSL>), options);
 
  if (!httpContext) {
+ UWS_LOG_REQUEST(0, "Error: Failed to create a httpContext");
  return nullptr;
  }
 

src/Log.h

@@ -0,0 +1,72 @@
+#ifndef UWS_LOG_H
+#define UWS_LOG_H
+#include <array>
+#include <functional>
+#include <iostream>
+#include <string_view>
+
+#define UWS_LOG_LEVEL 0 // override this to get more verbose logging
+
+namespace uWS {
+
+/*!
+ * \brief Log a message. The user of this lib is free to override this function object with a custom logger.
+ * \param [in] message The message to be logged.
+ * \param [in] logLevel The severity of the message. 0 is error, 1 is warning, 2 is info, 3 is debug. With each increment the severity decrements.
+ */
+typedef std::function<void(std::string_view message, int logLevel)> LogFunction;
+
+inline LogFunction log = [](std::string_view message, int logLevel) -> void {
+ if(logLevel <= 1) {
+ std::cerr << message << std::endl;
+ }
+ else {
+ std::cout << message << std::endl;
+ }
+};
+
+class LogBuffer
+{
+ private:
+ std::array<char,1024> buf{0};
+ size_t cursor = 0;
+
+ LogBuffer& operator<< (std::string_view sv) {
+ const size_t bytesFree = buf.size() - cursor;
+ if(sv.size() > bytesFree)
+ return *this;
+ memcpy(&buf[cursor], sv.data(), sv.size());
+ cursor += sv.size();
+ return *this;
+ }
+
+ public:
+ template <typename T>
+ void put(T msg) {
+ *this << msg;
+ }
+ template <typename T, typename... Ts>
+ void put(T t, Ts... ts) {
+ put(t);
+ put(ts...);
+ }
+ std::string_view get() {
+ std::string_view ret(buf.data(), cursor);
+ cursor = 0;
+ return ret;
+ }
+};
+
+thread_local LogBuffer logBuffer;
+
+#define UWS_LOG_REQUEST(loglevel, ...) { \
+ if constexpr(loglevel <= UWS_LOG_LEVEL) { \
+ ::uWS::logBuffer.put(__VA_ARGS__); \
+ ::uWS::log(::uWS::logBuffer.get(), loglevel); \
+ } \
+}
+
+} // namespace uWS
+
+#endif // UWS_LOG_H
+