[Common]Use folder_change_reader in file watcher to improve performance (#30827)

src/common/SettingsAPI/FileWatcher.cpp

@@ -1,5 +1,6 @@
 #include "pch.h"
 #include "FileWatcher.h"
+#include <utils/winapi_error.h>
 
 std::optional<FILETIME> FileWatcher::MyFileTime()
 {
@@ -19,50 +20,47 @@ std::optional<FILETIME> FileWatcher::MyFileTime()
     return result;
 }
 
-void FileWatcher::Run()
-{
-    while (1)
-    {
-        auto lastWrite = MyFileTime();
-        if (!m_lastWrite.has_value())
-        {
-            m_lastWrite = lastWrite;
-        }
-        else if (lastWrite.has_value())
-        {
-            if (m_lastWrite->dwHighDateTime != lastWrite->dwHighDateTime ||
-                m_lastWrite->dwLowDateTime != lastWrite->dwLowDateTime)
-            {
-                m_lastWrite = lastWrite;
-                m_callback();
-            }
-        }
-
-        if (WaitForSingleObject(m_abortEvent, m_refreshPeriod) == WAIT_OBJECT_0)
-        {
-            return;
-        }
-    }
-}
-
-FileWatcher::FileWatcher(const std::wstring& path, std::function<void()> callback, DWORD refreshPeriod) :
-    m_refreshPeriod(refreshPeriod),
+FileWatcher::FileWatcher(const std::wstring& path, std::function<void()> callback) :
     m_path(path),
     m_callback(callback)
 {
-    m_abortEvent = CreateEventW(nullptr, TRUE, FALSE, nullptr);
-    if (m_abortEvent)
+    std::filesystem::path fsPath(path);
+    m_file_name = fsPath.filename();
+    std::transform(m_file_name.begin(), m_file_name.end(), m_file_name.begin(), ::towlower);
+    m_folder_change_reader = wil::make_folder_change_reader_nothrow(
+        fsPath.parent_path().c_str(),
+        false,
+        wil::FolderChangeEvents::LastWriteTime,
+        [this](wil::FolderChangeEvent, PCWSTR fileName) {
+            std::wstring lowerFileName(fileName);
+            std::transform(lowerFileName.begin(), lowerFileName.end(), lowerFileName.begin(), ::towlower);
+
+            if (m_file_name.compare(fileName) == 0)
+            {
+                auto lastWrite = MyFileTime();
+                if (!m_lastWrite.has_value())
+                {
+                    m_lastWrite = lastWrite;
+                }
+                else if (lastWrite.has_value())
+                {
+                    if (m_lastWrite->dwHighDateTime != lastWrite->dwHighDateTime ||
+                        m_lastWrite->dwLowDateTime != lastWrite->dwLowDateTime)
+                    {
+                        m_lastWrite = lastWrite;
+                        m_callback();
+                    }
+                }
+            }
+        });
+
+    if (!m_folder_change_reader)
     {
-        m_thread = std::thread([this]() { Run(); });
+        Logger::error(L"Failed to start folder change reader for path {}. {}", path, get_last_error_or_default(GetLastError()));
     }
 }
 
 FileWatcher::~FileWatcher()
 {
-    if (m_abortEvent)
-    {
-        SetEvent(m_abortEvent);
-        m_thread.join();
-        CloseHandle(m_abortEvent);
-    }
+    m_folder_change_reader.reset();
 }

src/common/SettingsAPI/FileWatcher.h

@@ -11,16 +11,14 @@
 
 class FileWatcher
 {
-    DWORD m_refreshPeriod;
     std::wstring m_path;
+    std::wstring m_file_name;
     std::optional<FILETIME> m_lastWrite;
     std::function<void()> m_callback;
-    HANDLE m_abortEvent;
-    std::thread m_thread;
-    
+    wil::unique_folder_change_reader_nothrow m_folder_change_reader;
+
     std::optional<FILETIME> MyFileTime();
-    void Run();
 public:
-    FileWatcher(const std::wstring& path, std::function<void()> callback, DWORD refreshPeriod = 1000);
+    FileWatcher(const std::wstring& path, std::function<void()> callback);
     ~FileWatcher();
 };

src/common/SettingsAPI/SettingsAPI.vcxproj

@@ -47,10 +47,15 @@
     <ProjectReference Include="..\..\common\version\version.vcxproj">
       <Project>{cc6e41ac-8174-4e8a-8d22-85dd7f4851df}</Project>
     </ProjectReference>
+    <ProjectReference Include="..\logger\logger.vcxproj">
+      <Project>{d9b8fc84-322a-4f9f-bbb9-20915c47ddfd}</Project>
+    </ProjectReference>
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <Import Project="..\..\..\deps\spdlog.props" />
   <ImportGroup Label="ExtensionTargets">
     <Import Project="..\..\..\packages\Microsoft.Windows.CppWinRT.2.0.221104.6\build\native\Microsoft.Windows.CppWinRT.targets" Condition="Exists('..\..\..\packages\Microsoft.Windows.CppWinRT.2.0.221104.6\build\native\Microsoft.Windows.CppWinRT.targets')" />
+    <Import Project="..\..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.220914.1\build\native\Microsoft.Windows.ImplementationLibrary.targets" Condition="Exists('..\..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.220914.1\build\native\Microsoft.Windows.ImplementationLibrary.targets')" />
   </ImportGroup>
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
@@ -58,5 +63,6 @@
     </PropertyGroup>
     <Error Condition="!Exists('..\..\..\packages\Microsoft.Windows.CppWinRT.2.0.221104.6\build\native\Microsoft.Windows.CppWinRT.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\Microsoft.Windows.CppWinRT.2.0.221104.6\build\native\Microsoft.Windows.CppWinRT.props'))" />
     <Error Condition="!Exists('..\..\..\packages\Microsoft.Windows.CppWinRT.2.0.221104.6\build\native\Microsoft.Windows.CppWinRT.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\Microsoft.Windows.CppWinRT.2.0.221104.6\build\native\Microsoft.Windows.CppWinRT.targets'))" />
+    <Error Condition="!Exists('..\..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.220914.1\build\native\Microsoft.Windows.ImplementationLibrary.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.220914.1\build\native\Microsoft.Windows.ImplementationLibrary.targets'))" />
   </Target>
 </Project>

src/common/SettingsAPI/pch.h

@@ -9,3 +9,5 @@
 #include <filesystem>
 #include <fstream>
 
+#include <common/logger/logger.h>
+#include <wil/filesystem.h>

src/modules/alwaysontop/AlwaysOnTop/pch.h

@@ -3,6 +3,7 @@
 #include <windows.h>
 #include <winrt/base.h>
 #include <wil/resource.h>
+#include <wil/filesystem.h>
 #include <ProjectTelemetry.h>
 #include <common/logger/logger.h>
 

src/modules/fancyzones/FancyZonesLib/pch.h

@@ -13,8 +13,9 @@
 #include <ShellScalingApi.h>
 #include <strsafe.h>
 #include <TraceLoggingActivity.h>
-#include <wil\resource.h>
-#include <wil\result.h>
+#include <wil/filesystem.h>
+#include <wil/resource.h>
+#include <wil/result.h>
 #include <winrt/windows.foundation.h>
 #include <psapi.h>
 #include <shared_mutex>

src/modules/videoconference/VideoConferenceModule/pch.h

@@ -9,6 +9,7 @@
 
 #include <wil/resource.h>
 #include <wil/com.h>
+#include <wil/filesystem.h>
 
 #include <string_view>
 #include <optional>