Move duplicated utilities to the common util folder and remove NEXT_DIR (#29)

* move things to the common library and remove next_dir

* fix for windows

* one last windows fix

* last fix for real this time

* debug listener test

* fix listener threading bug

common/util/Timer.cpp

@@ -0,0 +1,54 @@
+#include "Timer.h"
+
+#ifdef _WIN32
+#include <Windows.h>
+#define MS_PER_SEC 1000ULL  // MS = milliseconds
+#define US_PER_MS 1000ULL   // US = microseconds
+#define HNS_PER_US 10ULL    // HNS = hundred-nanoseconds (e.g., 1 hns = 100 ns)
+#define NS_PER_US 1000ULL
+
+#define HNS_PER_SEC (MS_PER_SEC * US_PER_MS * HNS_PER_US)
+#define NS_PER_HNS (100ULL)  // NS = nanoseconds
+#define NS_PER_SEC (MS_PER_SEC * US_PER_MS * NS_PER_US)
+
+int Timer::clock_gettime_monotonic(struct timespec* tv) {
+  static LARGE_INTEGER ticksPerSec;
+  LARGE_INTEGER ticks;
+  double seconds;
+
+  if (!ticksPerSec.QuadPart) {
+    QueryPerformanceFrequency(&ticksPerSec);
+    if (!ticksPerSec.QuadPart) {
+      errno = ENOTSUP;
+      return -1;
+    }
+  }
+
+  QueryPerformanceCounter(&ticks);
+
+  seconds = (double)ticks.QuadPart / (double)ticksPerSec.QuadPart;
+  tv->tv_sec = (time_t)seconds;
+  tv->tv_nsec = (long)((ULONGLONG)(seconds * NS_PER_SEC) % NS_PER_SEC);
+
+  return 0;
+}
+#endif
+
+void Timer::start() {
+#ifdef __linux__
+  clock_gettime(CLOCK_MONOTONIC, &_startTime);
+#elif _WIN32
+  clock_gettime_monotonic(&_startTime);
+#endif
+}
+
+int64_t Timer::getNs() {
+  struct timespec now = {};
+#ifdef __linux__
+  clock_gettime(CLOCK_MONOTONIC, &now);
+#elif _WIN32
+  clock_gettime_monotonic(&now);
+#endif
+  return (int64_t)(now.tv_nsec - _startTime.tv_nsec) +
+         1000000000 * (now.tv_sec - _startTime.tv_sec);
+}