Send validator telemetry to the private overlay (#1325)

* Send validator telemetry to the private overlay

* Improve rotating neighbours in overlays

tdutils/td/utils/port/Stat.cpp

@@ -472,4 +472,45 @@ Result<TotalMemStat> get_total_mem_stat() {
 #endif
 }
 
+Result<uint32> get_cpu_cores() {
+#if TD_LINUX
+  uint32 result = 0;
+  TRY_RESULT(fd, FileFd::open("/proc/cpuinfo", FileFd::Read));
+  SCOPE_EXIT {
+    fd.close();
+  };
+  std::string data;
+  char buf[10000];
+  while (true) {
+    TRY_RESULT(size, fd.read(MutableSlice{buf, sizeof(buf) - 1}));
+    if (size == 0) {
+      break;
+    }
+    buf[size] = '\0';
+    data += buf;
+  }
+  size_t i = 0;
+  while (i < data.size()) {
+    const char *line_begin = data.data() + i;
+    while (i < data.size() && data[i] != '\n') {
+      ++i;
+    }
+    auto line_end = data.data() + i;
+    ++i;
+    Slice line{line_begin, line_end};
+    size_t j = 0;
+    while (j < line.size() && line[j] != ' ' && line[j] != '\t' && line[j] != ':') {
+      ++j;
+    }
+    Slice name = line.substr(0, j);
+    if (name == "processor") {
+      ++result;
+    }
+  }
+  return result;
+#else
+  return Status::Error("Not supported");
+#endif
+}
+
 }  // namespace td