add fs_event.hpp

Author: neevek

CMakeLists.txt

@@ -24,7 +24,7 @@ ExternalProject_Add(libuv
   #GIT_REPOSITORY "https://github.com/libuv/libuv.git"
   GIT_REPOSITORY "$ENV{HOME}/dev/github/libuv"
   #GIT_TAG "v1.x"
-  GIT_TAG "v1.33.1"
+  GIT_TAG "v1.30.1"
   CONFIGURE_COMMAND ${CONFIGURE_COMMMAND}
   BUILD_IN_SOURCE 1
   BUILD_COMMAND $(MAKE)

src/fs_event.hpp

@@ -0,0 +1,101 @@
+/*******************************************************************************
+**          File: fs_event.hpp
+**        Author: neevek <[email protected]>.
+** Creation Time: 2020-04-12 Sun 03:22 PM
+**   Description: a wrapper of uv_fs_event_t
+*******************************************************************************/
+#ifndef UVCPP_FS_EVENT_H_
+#define UVCPP_FS_EVENT_H_
+#include "handle.hpp"
+#include <thread>
+
+namespace uvcpp {
+  struct EvFsEvent : public Event {
+    enum class Event : int {
+      kRename = 1,
+      kChange = 2
+    };
+
+    EvFsEvent(const char *path, Event events, int status) :
+      path(path ? path : ""), events(events), status(status) { }
+
+    std::string path; // could be empty
+    Event events;
+    int status;
+  };
+
+  class FsEvent : public Handle<uv_fs_event_t, FsEvent> {
+    friend class Resource;
+    friend class Handle;
+
+    public:
+      enum class Flag : unsigned int {
+        kWatchEntry = 1,
+        kStat       = 2,
+        kRecursive  = 4
+      };
+
+      friend FsEvent::Flag operator|(FsEvent::Flag lhs, FsEvent::Flag rhs) {
+        typedef typename std::underlying_type<FsEvent::Flag>::type underlying;
+        return static_cast<FsEvent::Flag>(
+          static_cast<underlying>(lhs) | static_cast<underlying>(rhs));
+      }
+
+    protected:
+      FsEvent(const std::shared_ptr<Loop> &loop) : Handle(loop) {}
+
+      virtual bool init() override {
+        if (uv_fs_event_init(this->getLoop()->getRaw(), get()) != 0) {
+          LOG_E("uv_fs_event_init failed");
+          return false;
+        }
+        return true;
+      }
+
+    public:
+      void start(const std::string &path, Flag flags) {
+        if (path.empty()) {
+          this->reportError("path is empty", 0);
+          return;
+        }
+
+        int err;
+        if ((err = uv_fs_event_start(
+              static_cast<uv_fs_event_t *>(this->get()),
+              onFsEventCallback, path.c_str(),
+              static_cast<unsigned int>(flags))) != 0) {
+          this->reportError("uv_fs_event_start", err);
+        }
+      }
+
+      void stop() {
+        int err;
+        if ((err = uv_fs_event_stop(
+              static_cast<uv_fs_event_t *>(this->get()))) != 0) {
+          this->reportError("uv_fs_event_stop", err);
+        }
+      }
+
+    private:
+      static void onFsEventCallback(
+        uv_fs_event_t *handle, const char *filename, int events, int status) {
+        size_t size = 2048;
+        char path[size];
+
+        auto ret = uv_fs_event_getpath(handle, path, &size);
+        if (ret == UV_ENOBUFS) {
+          static_cast<FsEvent *>(handle->data)->reportError(
+            "uv_fs_event_getpath failed, buffer size too small", ret);
+
+        } else {
+          static_cast<FsEvent *>(handle->data)->template
+            publish<EvFsEvent>(EvFsEvent{
+              path, static_cast<EvFsEvent::Event>(events), status
+            });
+        }
+      }
+  };
+
+} /* end of namespace: uvcpp */
+
+#endif /* end of include guard: UVCPP_FS_EVENT_H_ */

src/uvcpp.h

@@ -15,6 +15,7 @@
 #include "timer.hpp"
 #include "prepare.hpp"
 #include "poll.hpp"
+#include "fs_event.hpp"
 #include "ext/poll_unix_sock.hpp"
 
 #endif /* end of include guard: UVCPP_H_ */

test/CMakeLists.txt

@@ -52,7 +52,7 @@ SET_LIBRARY_PROP(uv uvcpp "${UV_LIBRARY_DIR}/libuv.a")
 ExternalProject_Add(gtest
   PREFIX "${CMAKE_BINARY_DIR}/deps"
   GIT_REPOSITORY "https://github.com/google/googletest.git"
-  GIT_TAG "master"
+  GIT_TAG "release-1.8.1"
   CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/deps/installed
   GIT_SHALLOW 1
   GIT_PROGRESS 1
@@ -89,6 +89,7 @@ ADD_UVCPP_TEST(timer uvcpp/timer.cc)
 ADD_UVCPP_TEST(prepare uvcpp/prepare.cc)
 ADD_UVCPP_TEST(work uvcpp/work.cc)
 ADD_UVCPP_TEST(poll uvcpp/poll.cc)
+ADD_UVCPP_TEST(fs_event uvcpp/fs_event.cc)
 
 # build a executable without gtest, so we can debug the code
 #add_executable(testpipe uvcpp/testpipe.cc)

test/uvcpp/fs_event.cc

@@ -0,0 +1,67 @@
+#include <gtest/gtest.h>
+#include "uvcpp.h"
+#include <fstream>
+
+using namespace uvcpp;
+
+TEST(FsEvent, TestFileChange) {
+  auto destroyed = false;
+  auto count = 0;
+  {
+    auto loop = std::make_shared<Loop>();
+    ASSERT_TRUE(loop->init());
+
+    auto fsEvent = FsEvent::create(loop);
+    ASSERT_TRUE(!!fsEvent);
+
+    fsEvent->on<EvError>([](const auto &e, auto &fsEvent) {
+      FAIL() << "fsEvent failed with status: " << e.status << ", msg: " << e.message;
+    });
+    fsEvent->on<EvClose>([fe = fsEvent](const auto &e, auto &fsEvent) {
+      LOG_D("fsEvent closed: %li", fe.use_count());
+    });
+    fsEvent->once<EvDestroy>([&destroyed, fe = &fsEvent](const auto &e, auto &fsEvent) {
+      LOG_D("fsEvent destroyed: %li", fe->use_count());
+      destroyed = true;
+    });
+
+    fsEvent->on<EvFsEvent>([&count](const auto &e, auto &fsEvent) {
+      LOG_D("haha changed: %d", e.events);
+      if (e.events == EvFsEvent::Event::kChange) {
+        if (++count >= 2) {
+          fsEvent.stop();
+          fsEvent.close();
+        }
+      }
+    });
+
+    auto testFile = "./test_fs_event.txt";
+    int fd = open(testFile, O_RDWR|O_CREAT, 0644);
+    if (fd != -1) {
+      close(fd);
+    }
+
+    fsEvent->start(testFile, FsEvent::Flag::kRecursive);
+
+    LOG_D("will run thread");
+    auto t = std::thread([&](){
+      auto changeFile = [&]() {
+        LOG_D("will change file: %s", testFile);
+        std::ofstream os(testFile, std::ios::binary);
+        os << "test";
+        os.close();
+      };
+      changeFile();
+      changeFile();
+      unlink(testFile);
+    });
+
+    LOG_D("will run loop");
+
+    loop->run();
+    t.join();
+  }
+
+  ASSERT_TRUE(destroyed);
+  ASSERT_TRUE(count == 2);
+}