From ce98a59397a039c19ee813ded5344b74ef95b6e2 Mon Sep 17 00:00:00 2001
From: tqcq <99722391+tqcq@users.noreply.github.com>
Date: Fri, 29 Dec 2023 11:04:52 +0800
Subject: [PATCH] feat add defer

---
 src/ulib/utils/defer.h               | 51 +++++++++++++++++++++++
 tests/CMakeLists.txt                 |  1 +
 tests/ulib/system/timer_unittest.cpp | 28 +++++++------
 tests/ulib/utils/defer_unittest.cpp  | 60 ++++++++++++++++++++++++++++
 4 files changed, 128 insertions(+), 12 deletions(-)
 create mode 100644 src/ulib/utils/defer.h
 create mode 100644 tests/ulib/utils/defer_unittest.cpp

diff --git a/src/ulib/utils/defer.h b/src/ulib/utils/defer.h
new file mode 100644
index 0000000..5e280b9
--- /dev/null
+++ b/src/ulib/utils/defer.h
@@ -0,0 +1,51 @@
+#ifndef ULIB_SRC_ULIB_UTILS_DEFER_H_
+#define ULIB_SRC_ULIB_UTILS_DEFER_H_
+#include "ulib/base/noncopyable.h"
+#include "ulib/base/stringize_macros.h"
+#include <memory>
+#include <algorithm>
+#include <vector>
+#include <functional>
+
+namespace ulib {
+class Defer : NonCopyable {
+public:
+    using DeferFunc = std::function<void()>;
+
+    Defer() = default;
+
+    Defer(const DeferFunc &defer_func) { Add(defer_func); }
+
+    Defer(DeferFunc &&defer_func) { Add(std::move(defer_func)); }
+
+    Defer(Defer &&other) noexcept : defer_funcs_(std::move(other.defer_funcs_))
+    {}
+
+    ~Defer()
+    {
+        std::for_each(defer_funcs_.rbegin(), defer_funcs_.rend(),
+                      [](const DeferFunc &defer_func) { defer_func(); });
+    }
+
+    template<typename F, typename... Args>
+    void Add(F &&func, Args &&...args)
+    {
+        defer_funcs_.push_back(
+            std::bind(std::forward<F>(func), std::forward<Args>(args)...));
+    }
+
+    void Clear() { defer_funcs_.clear(); }
+
+private:
+    std::vector<DeferFunc> defer_funcs_;
+};
+
+#define _ULIB_DEFER_CONCAT(a, b) a##b
+#define ULIB_DEFER_CONCAT(a, b) _ULIB_DEFER_CONCAT(a, b)
+
+#define defer(x)                                                               \
+    ::ulib::Defer ULIB_DEFER_CONCAT(__ulib_defer__, __LINE__) =                \
+        ::ulib::Defer(x);
+
+}// namespace ulib
+#endif// ULIB_SRC_ULIB_UTILS_DEFER_H_
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d8e9918..caa4802 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -10,6 +10,7 @@ add_executable(ulib_test
         ulib/system/thread_unittest.cpp
         ulib/system/thread_pool_unittest.cpp
         ulib/system/timer_unittest.cpp
+        ulib/utils/defer_unittest.cpp
 )
 target_link_libraries(ulib_test PRIVATE
         ulib
diff --git a/tests/ulib/system/timer_unittest.cpp b/tests/ulib/system/timer_unittest.cpp
index 9029ca7..ad91e61 100644
--- a/tests/ulib/system/timer_unittest.cpp
+++ b/tests/ulib/system/timer_unittest.cpp
@@ -7,30 +7,34 @@
 class TimerTest : public ::testing::Test {
 protected:
     void SetUp() override { latch_ = nullptr; }
+
     void TearDown() override { delete latch_; }
 
 protected:
     ulib::CountDownLatch *latch_;
 };
 
-TEST_F(TimerTest, OnceTrigger) {
+TEST_F(TimerTest, OnceTrigger)
+{
     latch_ = new ulib::CountDownLatch(1);
-    ulib::TimerId timer_id = ulib::TimerManager::AddTimer([&]{
-        latch_->CountDown();
-    }, 1000);
+    ulib::TimerId timer_id =
+        ulib::TimerManager::AddTimer([&] { latch_->CountDown(); }, 1000);
     latch_->Await();
     ulib::TimerManager::CancelTimer(timer_id);
 }
 
-TEST_F(TimerTest, PeriodTrigger) {
+TEST_F(TimerTest, PeriodTrigger)
+{
     latch_ = new ulib::CountDownLatch(3);
     std::atomic_int cnt(3);
-    ulib::TimerId timer_id = ulib::TimerManager::AddTimer([&]{
-        if (cnt.fetch_sub(1) > 0) {
-            ULOG_INFO("timer.unittest", "start count down: {}", cnt);
-            latch_->CountDown();
-        }
-    }, 1000, 3000);
+    ulib::TimerId timer_id = ulib::TimerManager::AddTimer(
+        [&] {
+            if (cnt.fetch_sub(1) > 0) {
+                ULOG_INFO("timer.unittest", "start count down: {}", cnt);
+                latch_->CountDown();
+            }
+        },
+        1000, 1000);
     latch_->Await();
     ulib::TimerManager::CancelTimer(timer_id);
-}
\ No newline at end of file
+}
diff --git a/tests/ulib/utils/defer_unittest.cpp b/tests/ulib/utils/defer_unittest.cpp
new file mode 100644
index 0000000..fbc5c26
--- /dev/null
+++ b/tests/ulib/utils/defer_unittest.cpp
@@ -0,0 +1,60 @@
+#include <gtest/gtest.h>
+#include <ulib/utils/defer.h>
+
+TEST(Defer, Defer)
+{
+    int i = 0;
+    {
+        defer([&i]() { i++; });
+        EXPECT_EQ(i, 0);
+    }
+    EXPECT_EQ(i, 1);
+}
+
+TEST(Defer, DeferFunc)
+{
+    int i = 0;
+    {
+        defer([&i]() { i++; });
+        EXPECT_EQ(i, 0);
+    }
+    EXPECT_EQ(i, 1);
+}
+
+TEST(Defer, DeferMove)
+{
+    int i = 0;
+    {
+        defer([&i]() { i++; });
+        EXPECT_EQ(i, 0);
+        defer([&i]() { i++; });
+        EXPECT_EQ(i, 0);
+    }
+    EXPECT_EQ(i, 2);
+}
+
+TEST(Defer, Add)
+{
+    int i = 0;
+    {
+        ulib::Defer defer;
+        defer.Add([&i]() { i++; });
+        EXPECT_EQ(i, 0);
+        defer.Add([&i]() { i++; });
+        EXPECT_EQ(i, 0);
+    }
+    EXPECT_EQ(i, 2);
+}
+
+TEST(Defer, Clear)
+{
+    int i = 0;
+    {
+        ulib::Defer defer;
+        defer.Add([&i]() { i++; });
+        EXPECT_EQ(i, 0);
+        defer.Clear();
+        EXPECT_EQ(i, 0);
+    }
+    EXPECT_EQ(i, 0);
+}