CMakeLists.txt

@@ -279,13 +279,13 @@ if(TILE_BUILD_TESTS)
     target_sources(${PROJECT_NAME}_test_all PRIVATE ${test_file})
   endmacro()
 
-  tile_add_test(base_exposed_var_test "tile/base/exposed_var_test.cc")
   macro(tile_add_test test_name test_file)
     tile_add_custom_test(${test_name} ${test_file})
     add_test(NAME ${test_name} COMMAND ${test_name})
   endmacro()
 
-tile_add_test(fiber_detail_scheduler_test "tile/fiber/detail/scheduler_test.cc")
+  tile_add_test(base_exposed_var_test "tile/base/exposed_var_test.cc")
+  tile_add_test(fiber_detail_scheduler_test "tile/fiber/detail/scheduler_test.cc")
   tile_add_test(base_internal_meta_test "tile/base/internal/meta_test.cc")
   # tile_add_test(net_internal_http_engine_test
   # "tile/net/internal/http_engine_test.cc")

third_party/glog/CMakeLists.txt

@@ -39,7 +39,7 @@ option(PRINT_UNSYMBOLIZED_STACK_TRACES
        "Print file offsets in traces instead of symbolizing" OFF)
 option(WITH_CUSTOM_PREFIX "Enable support for user-generated message prefixes"
        ON)
-option(WITH_GFLAGS "Use gflags" ON)
+option(WITH_GFLAGS "Use gflags" OFF)
 option(WITH_GTEST "Use Google Test" OFF)
 option(WITH_PKGCONFIG "Enable pkg-config support" OFF)
 option(WITH_SYMBOLIZE "Enable symbolize module" ON)
@@ -699,8 +699,8 @@ endif(HAVE_PTHREAD)
 
 if(gflags_FOUND)
   # Prefer the gflags target that uses double colon convention
-  # target_link_libraries(glog PRIVATE gflags::gflags) 
-    # if (TARGET
+  # target_link_libraries(glog PRIVATE gflags::gflags)
+  # if (TARGET
   # gflags::gflags) target_link_libraries (glog PUBLIC gflags::gflags) else
   # (TARGET gflags::gflags) target_link_libraries (glog PUBLIC gflags) endif
   # (TARGET gflags::gflags)

tile/base/exposed_var.cc

@@ -5,7 +5,7 @@
 #include "tile/base/string.h"
 
 namespace tile {
-namespace exposed_var {
+// namespace exposed_var {
 
 namespace {
 #define CHECK_PATH(path)                                                       \
@@ -63,19 +63,20 @@ std::string JoinPath(Slice a, Slice b) {
 
 std::string SubstituteEscapedSlashForZero(Slice path) {
   TILE_CHECK(path.find('\0') == tile::Slice::npos);
-  return Replace(path, "\\/", "\0");
+  return Replace(path, "\\/", '\0');
 }
 
 std::string SubstituteZeroForEscapedSlash(Slice path) {
-  return Replace(path, "\0", "\\/");
+  return Replace(path, '\0', "\\/");
 }
 
 std::string UnescapeZeroToPlainSlash(Slice path) {
-  return Replace(path, "\0", "/");
+  return Replace(path, '\0', '/');
 }
 
 } // namespace
 
+// } // namespace exposed_var
 ExposedVarGroup::Handle
 ExposedVarGroup::Add(Slice rel_path, std::function<Json::Value()> value) {
 
@@ -296,5 +297,4 @@ std::optional<Json::Value> ExposedVarDynamicTree::TryGet(Slice rel_path) const {
   return *ptr;
 }
 
-} // namespace exposed_var
 } // namespace tile

tile/base/exposed_var.h

@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include "tile/base/chrono.h"
 #include "tile/base/deferred.h"
 #include "tile/base/internal/meta.h"
 #include "tile/base/optional.h"
@@ -46,15 +47,21 @@ auto ToJsonValue(const T &t)
 
 template <typename T>
 auto ToJsonValue(const T &t)
-    -> enable_if_t<std::is_same<std::string,
-                                decltype(format_as(std::declval<T>()))>::value,
-                   Json::Value> {
+    -> enable_if_t<
+        !std::is_integral<T>::value && !std::is_floating_point<T>::value &&
+            !std::is_same<T, std::string>::value &&
+            !std::is_same<T, const char *>::value &&
+            !std::is_same<T, bool>::value &&
+            std::is_same<std::string,
+                         decltype(format_as(std::declval<T>()))>::value,
+        Json::Value> {
   return Json::Value(format_as(t));
 }
 
 template <class T> Json::Value ToJsonValue(const std::atomic<T> &v) {
   return ToJsonValue(v.load(std::memory_order_relaxed));
 }
+} // namespace exposed_var
 
 class ExposedVarDynamicTree;
 
@@ -142,7 +149,45 @@ private:
   ExposedVarGroup::Handle handle_;
 };
 
-} // namespace exposed_var
+namespace detail {
+template <typename T> struct IdentityTime {
+  std::uint64_t operator()(const T &val) const {
+    return (ReadSteadyClock() - std::chrono::steady_clock::time_point()) /
+           std::chrono::nanoseconds(1);
+  }
+};
+} // namespace detail
+
+template <typename T, typename F = detail::IdentityTime<T>>
+class ExposedMetrics {
+public:
+  explicit ExposedMetrics(Slice rel_path) {
+    LinkToParent(rel_path, ExposedVarGroup::FindOrCreate("/"));
+  }
+
+private:
+  Json::Value ToJsonValue(const T &v) {
+    Json::Value result;
+    std::unordered_map<std::string, T> m = {{"1s", 1}};
+    for (auto &&item : m) {
+    }
+  }
+
+  void LinkToParent(Slice rel_path, ExposedVarGroup *parent) {
+    handle_ = parent->Add(rel_path, [this] { return ToJsonValue(obj_); });
+  }
+
+private:
+  T obj_{};
+  ExposedVarGroup::Handle handle_;
+};
+
+template <typename T> using ExposedCounter = ExposedVar<T>;
+template <typename T> using ExposedGauge = ExposedVar<T>;
+template <typename T> using ExposedMiner = ExposedVar<T>;
+template <typename T> using ExposedMaxer = ExposedVar<T>;
+template <typename T> using ExposedAverager = ExposedVar<T>;
+
 } // namespace tile
 
 #endif // TILE_BASE_EXPOSED_VAR_H

tile/base/exposed_var_test.cc

@@ -3,4 +3,36 @@
 #include "gtest/gtest.h"
 #include "json/json.h"
 
-namespace tile {}
+namespace tile {
+ExposedVarGroup *GetFancyGroup() {
+  return ExposedVarGroup::FindOrCreate("/a/b");
+}
+Json::Value GetTree() {
+  Json::Value jsv;
+  jsv["dir"]["sub-dir"]["key"] = 5;
+  jsv["key"] = "6";
+  return jsv;
+}
+
+ExposedVar<int> v1("v1", 5);
+
+ExposedVar<double> f1("f1", 6.2, ExposedVarGroup::FindOrCreate("/x/y/z"));
+
+auto GreatGroup = ExposedVarGroup::FindOrCreate("/a/b");
+
+// `/a/b/ds1`
+ExposedVarDynamic<std::string>
+    ds1("ds1", [] { return "test_str"; }, GetFancyGroup());
+
+TEST(ExposedVar, Mutate) {
+  auto opt = ExposedVarGroup::TryGet("/");
+  ASSERT_TRUE(opt);
+  auto &&jsv = *opt;
+  ASSERT_EQ(5, jsv["v1"].asInt());
+  *v1 = 6;
+  jsv = *ExposedVarGroup::TryGet("/");
+  ASSERT_EQ(6, jsv["v1"].asInt());
+  *v1 = 5;
+}
+
+} // namespace tile

tile/base/write_mostly/metrics.h

@@ -0,0 +1,36 @@
+#ifndef TILE_BASE_WRITE_MOSTLY_METRICS_H
+#define TILE_BASE_WRITE_MOSTLY_METRICS_H
+
+#pragma once
+
+#include "tile/base/internal/meta.h"
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+#include <utility>
+
+namespace tile {
+
+namespace write_mostly {
+namespace detail {
+template <typename T> struct MetricsStats;
+}
+} // namespace write_mostly
+
+template <typename T> struct MetricsStats {
+  using SumType = internal::conditional_t<
+      std::is_integral<T>::value,
+      internal::conditional_t<std::is_signed<T>::value, std::int64_t,
+                              std::uint64_t>,
+      long double>;
+
+  SumType sum;
+  std::size_t cnt;
+  T max;
+  T min;
+  T average;
+};
+
+} // namespace tile
+
+#endif // TILE_BASE_WRITE_MOSTLY_METRICS_H

tile/base/write_mostly/write_mostly.h

@@ -0,0 +1,18 @@
+#ifndef TILE_BASE_WRITE_MOSTLY_WRITE_MOSTLY_H
+#define TILE_BASE_WRITE_MOSTLY_WRITE_MOSTLY_H
+
+#pragma once
+
+#include <chrono>
+#include <memory>
+#include <mutex>
+
+namespace tile {
+template <typename Traits> class WriteMostly {
+  using T = typename Traits::Type;
+
+public:
+};
+} // namespace tile
+
+#endif // TILE_BASE_WRITE_MOSTLY_WRITE_MOSTLY_H

tile/init.cc

@@ -53,17 +53,22 @@ int Start(int argc, char **argv, std::function<int(int, char **)> cb,
     google::InstallFailureSignalHandler();
   }
 
+  // Init gflags
   gflags::SetVersionString("0.1.0");
   gflags::ParseCommandLineFlags(&argc, &argv, true);
   detail::ApplyFlagOverrider();
 
+  // Init Glog
   google::InitGoogleLogging(argv[0]);
 
   TILE_LOG_INFO("Tile started.");
 
   TILE_PCHECK(signal(SIGPIPE, SIG_IGN) != SIG_ERR);
 
+  // Init BasicRuntime
   InitializeBasicRuntime();
+
+  // Run all initializers
   detail::RunAllInitializers();
 
   int rc = 0;

tile/testing/main.cc

@@ -11,9 +11,9 @@ namespace testing {
 int InitAndRunAllTests(int *argc, char **argv) {
   ::testing::InitGoogleTest(argc, argv);
 
-  if (gflags::GetCommandLineFlagInfoOrDie("logtostderr").is_default) {
-    FLAGS_logtostderr = true;
-  }
+  // if (gflags::GetCommandLineFlagInfoOrDie("logtostderr").is_default) {
+  //   FLAGS_logtostderr = true;
+  // }
 
   return Start(*argc, argv, [](int, char **) { return ::RUN_ALL_TESTS(); });
 }