nghttpx: Cache time for logging

src/shrpx.cc

@@ -275,6 +275,45 @@ void reopen_log_signal_cb(evutil_socket_t sig, short events, void *arg)
 }
 } // namespace
 
+namespace {
+char time_cache_buf[2][64];
+size_t time_cache_buf_idx = 0;
+} // namespace
+
+namespace {
+const char* cache_time(size_t idx)
+{
+  auto buf = time_cache_buf[idx];
+
+  buf[0] = '\0';
+
+  // Format data like this:
+  // 03/Jul/2014:00:19:38 +0900
+  struct tm tms;
+  auto now = time(nullptr);
+
+  if(localtime_r(&now, &tms) == nullptr) {
+    return buf;
+  }
+
+  if(strftime(buf, sizeof(time_cache_buf[0]), "%d/%b/%Y:%T %z", &tms) == 0) {
+    buf[0] = '\0';
+
+    return buf;
+  }
+
+  return buf;
+}
+} // namespace
+
+namespace {
+void refresh_cb(evutil_socket_t sig, short events, void *arg)
+{
+  time_cache_buf_idx ^= 1;
+  mod_config()->cached_time = cache_time(time_cache_buf_idx);
+}
+} // namespace
+
 namespace {
 int event_loop()
 {
@@ -356,11 +395,32 @@ int event_loop()
     }
   }
 
+  auto refresh_event = event_new(evbase, -1, EV_PERSIST, refresh_cb,
+                                 nullptr);
+
+  if(!refresh_event) {
+    LOG(ERROR) << "event_new failed";
+
+    exit(EXIT_FAILURE);
+  }
+
+  timeval refresh_timeout = { 1, 0 };
+  rv = event_add(refresh_event, &refresh_timeout);
+
+  if(rv == -1) {
+    LOG(ERROR) << "Adding refresh_event failed";
+
+    exit(EXIT_FAILURE);
+  }
+
   if(LOG_ENABLED(INFO)) {
     LOG(INFO) << "Entering event loop";
   }
   event_base_loop(evbase, 0);
 
+  if(refresh_event) {
+    event_free(refresh_event);
+  }
   if(reopen_log_signal_event) {
     event_free(reopen_log_signal_event);
   }
@@ -505,6 +565,7 @@ void fill_default_config()
     (mod_config()->http2_option, 1);
 
   mod_config()->tls_proto_mask = 0;
+  mod_config()->cached_time = cache_time(time_cache_buf_idx);
 }
 } // namespace
 

src/shrpx_config.h

@@ -199,6 +199,7 @@ struct Config {
   FILE *http2_upstream_dump_request_header;
   FILE *http2_upstream_dump_response_header;
   nghttp2_option *http2_option;
+  volatile const char *cached_time;
   size_t downstream_addrlen;
   size_t num_worker;
   size_t http2_max_concurrent_streams;

src/shrpx_log.cc

@@ -57,28 +57,6 @@ const char *SEVERITY_COLOR[] = {
 };
 } // namespace
 
-namespace {
-std::string get_datestr()
-{
-  return "";
-  // Format data like this:
-  // 03/Jul/2014:00:19:38 +0900
-  char buf[64];
-  struct tm tms;
-  auto now = time(nullptr);
-
-  if(localtime_r(&now, &tms) == nullptr) {
-    return "";
-  }
-
-  if(strftime(buf, sizeof(buf), "%d/%b/%Y:%T %z", &tms) == 0) {
-    return "";
-  }
-
-  return buf;
-}
-} // namespace
-
 int Log::severity_thres_ = WARNING;
 
 void Log::set_severity_level(int severity)
@@ -141,7 +119,7 @@ Log::~Log()
 
   rv = snprintf(buf, sizeof(buf),
                 "%s [%s%s%s] %s\n       %s(%s:%d)%s\n",
-                get_datestr().c_str(),
+                get_config()->cached_time,
                 tty ? SEVERITY_COLOR[severity_] : "",
                 SEVERITY_STR[severity_],
                 tty ? "\033[0m" : "",
@@ -201,7 +179,7 @@ void upstream_accesslog(const std::string& client_ip, unsigned int status_code,
 
   rv = snprintf(buf, sizeof(buf), fmt,
                 client_ip.c_str(),
-                get_datestr().c_str(),
+                get_config()->cached_time,
                 method,
                 path,
                 major,