win,fs: use the new Windows fast stat API (#4327)

Windows added a new API for file information, which doesn't have to
open the file thus greatly improving performance:
https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyname

The stat functions are already covered by tests, so no test was added
here. I considered comparing the result of old and new code, but that
would require exposing internal fs functions, and we would be testing
Windows functionality, not libuv.

3 files changed, 171 insertions, 30 deletions

diff --git a/src/win/fs.c b/src/win/fs.c
index 8414f778..4b29e597 100644
--- a/src/win/fs.c
+++ b/src/win/fs.c
@@ -147,6 +147,16 @@ static int uv__file_symlink_usermode_flag = SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGE
 
 static DWORD uv__allocation_granularity;
 
+typedef enum {
+  FS__STAT_PATH_SUCCESS,
+  FS__STAT_PATH_ERROR,
+  FS__STAT_PATH_TRY_SLOW
+} fs__stat_path_return_t;
+
+INLINE static void fs__stat_assign_statbuf_null(uv_stat_t* statbuf);
+INLINE static void fs__stat_assign_statbuf(uv_stat_t* statbuf,
+    FILE_STAT_BASIC_INFORMATION stat_info, int do_lstat);
+
 
 void uv__fs_init(void) {
   SYSTEM_INFO system_info;
@@ -1673,6 +1683,43 @@ void fs__closedir(uv_fs_t* req) {
   SET_REQ_RESULT(req, 0);
 }
 
+INLINE static fs__stat_path_return_t fs__stat_path(WCHAR* path,
+    uv_stat_t* statbuf, int do_lstat) {
+  FILE_STAT_BASIC_INFORMATION stat_info;
+
+  // Check if the new fast API is available.
+  if (!pGetFileInformationByName) {
+    return FS__STAT_PATH_TRY_SLOW;
+  }
+
+  // Check if the API call fails.
+  if (!pGetFileInformationByName(path, FileStatBasicByNameInfo, &stat_info,
+      sizeof(stat_info))) {
+    switch(GetLastError()) {
+      case ERROR_FILE_NOT_FOUND:
+      case ERROR_PATH_NOT_FOUND:
+      case ERROR_NOT_READY:
+      case ERROR_BAD_NET_NAME:
+        /* These errors aren't worth retrying with the slow path. */
+        return FS__STAT_PATH_ERROR;
+    }
+    return FS__STAT_PATH_TRY_SLOW;
+  }
+
+  // A file handle is needed to get st_size for links.
+  if ((stat_info.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+    return FS__STAT_PATH_TRY_SLOW;
+  }
+
+  if (stat_info.DeviceType == FILE_DEVICE_NULL) {
+    fs__stat_assign_statbuf_null(statbuf);
+    return FS__STAT_PATH_SUCCESS;
+  }
+
+  fs__stat_assign_statbuf(statbuf, stat_info, do_lstat);
+  return FS__STAT_PATH_SUCCESS;
+}
+
 INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
     int do_lstat) {
   size_t target_length = 0;
@@ -1681,6 +1728,7 @@ INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
   FILE_FS_VOLUME_INFORMATION volume_info;
   NTSTATUS nt_status;
   IO_STATUS_BLOCK io_status;
+  FILE_STAT_BASIC_INFORMATION stat_info;
 
   nt_status = pNtQueryVolumeInformationFile(handle,
                                             &io_status,
@@ -1696,13 +1744,7 @@ INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
 
   /* If it's NUL device set fields as reasonable as possible and return. */
   if (device_info.DeviceType == FILE_DEVICE_NULL) {
-    memset(statbuf, 0, sizeof(uv_stat_t));
-    statbuf->st_mode = _S_IFCHR;
-    statbuf->st_mode |= (_S_IREAD | _S_IWRITE) | ((_S_IREAD | _S_IWRITE) >> 3) |
-                        ((_S_IREAD | _S_IWRITE) >> 6);
-    statbuf->st_nlink = 1;
-    statbuf->st_blksize = 4096;
-    statbuf->st_rdev = FILE_DEVICE_NULL << 16;
+    fs__stat_assign_statbuf_null(statbuf);
     return 0;
   }
 
@@ -1726,14 +1768,65 @@ INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
 
   /* Buffer overflow (a warning status code) is expected here. */
   if (io_status.Status == STATUS_NOT_IMPLEMENTED) {
-    statbuf->st_dev = 0;
+    stat_info.VolumeSerialNumber.QuadPart = 0;
   } else if (NT_ERROR(nt_status)) {
     SetLastError(pRtlNtStatusToDosError(nt_status));
     return -1;
   } else {
-    statbuf->st_dev = volume_info.VolumeSerialNumber;
+    stat_info.VolumeSerialNumber.QuadPart = volume_info.VolumeSerialNumber;
+  }
+
+  stat_info.DeviceType = device_info.DeviceType;
+  stat_info.FileAttributes = file_info.BasicInformation.FileAttributes;
+  stat_info.NumberOfLinks = file_info.StandardInformation.NumberOfLinks;
+  stat_info.FileId.QuadPart =
+      file_info.InternalInformation.IndexNumber.QuadPart;
+  stat_info.ChangeTime.QuadPart =
+      file_info.BasicInformation.ChangeTime.QuadPart;
+  stat_info.CreationTime.QuadPart =
+      file_info.BasicInformation.CreationTime.QuadPart;
+  stat_info.LastAccessTime.QuadPart =
+      file_info.BasicInformation.LastAccessTime.QuadPart;
+  stat_info.LastWriteTime.QuadPart =
+      file_info.BasicInformation.LastWriteTime.QuadPart;
+  stat_info.AllocationSize.QuadPart =
+      file_info.StandardInformation.AllocationSize.QuadPart;
+
+  if (do_lstat &&
+      (file_info.BasicInformation.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+    /*
+     * If reading the link fails, the reparse point is not a symlink and needs
+     * to be treated as a regular file. The higher level lstat function will
+     * detect this failure and retry without do_lstat if appropriate.
+     */
+    if (fs__readlink_handle(handle, NULL, &target_length) != 0) {
+      fs__stat_assign_statbuf(statbuf, stat_info, do_lstat);
+      return -1;
+    }
+    stat_info.EndOfFile.QuadPart = target_length;
+  } else {
+    stat_info.EndOfFile.QuadPart =
+      file_info.StandardInformation.EndOfFile.QuadPart;
   }
 
+  fs__stat_assign_statbuf(statbuf, stat_info, do_lstat);
+  return 0;
+}
+
+INLINE static void fs__stat_assign_statbuf_null(uv_stat_t* statbuf) {
+  memset(statbuf, 0, sizeof(uv_stat_t));
+  statbuf->st_mode = _S_IFCHR;
+  statbuf->st_mode |= (_S_IREAD | _S_IWRITE) | ((_S_IREAD | _S_IWRITE) >> 3) |
+                      ((_S_IREAD | _S_IWRITE) >> 6);
+  statbuf->st_nlink = 1;
+  statbuf->st_blksize = 4096;
+  statbuf->st_rdev = FILE_DEVICE_NULL << 16;
+}
+
+INLINE static void fs__stat_assign_statbuf(uv_stat_t* statbuf,
+    FILE_STAT_BASIC_INFORMATION stat_info, int do_lstat) {
+  statbuf->st_dev = stat_info.VolumeSerialNumber.QuadPart;
+
   /* Todo: st_mode should probably always be 0666 for everyone. We might also
    * want to report 0777 if the file is a .exe or a directory.
    *
@@ -1765,50 +1858,43 @@ INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
   * target. Otherwise, reparse points must be treated as regular files.
   */
   if (do_lstat &&
-      (file_info.BasicInformation.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
-    /*
-     * If reading the link fails, the reparse point is not a symlink and needs
-     * to be treated as a regular file. The higher level lstat function will
-     * detect this failure and retry without do_lstat if appropriate.
-     */
-    if (fs__readlink_handle(handle, NULL, &target_length) != 0)
-      return -1;
+      (stat_info.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
     statbuf->st_mode |= S_IFLNK;
-    statbuf->st_size = target_length;
+    statbuf->st_size = stat_info.EndOfFile.QuadPart;
   }
 
   if (statbuf->st_mode == 0) {
-    if (file_info.BasicInformation.FileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+    if (stat_info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
       statbuf->st_mode |= _S_IFDIR;
       statbuf->st_size = 0;
     } else {
       statbuf->st_mode |= _S_IFREG;
-      statbuf->st_size = file_info.StandardInformation.EndOfFile.QuadPart;
+      statbuf->st_size = stat_info.EndOfFile.QuadPart;
     }
   }
 
-  if (file_info.BasicInformation.FileAttributes & FILE_ATTRIBUTE_READONLY)
+  if (stat_info.FileAttributes & FILE_ATTRIBUTE_READONLY)
     statbuf->st_mode |= _S_IREAD | (_S_IREAD >> 3) | (_S_IREAD >> 6);
   else
     statbuf->st_mode |= (_S_IREAD | _S_IWRITE) | ((_S_IREAD | _S_IWRITE) >> 3) |
                         ((_S_IREAD | _S_IWRITE) >> 6);
 
   uv__filetime_to_timespec(&statbuf->st_atim,
-                           file_info.BasicInformation.LastAccessTime.QuadPart);
+                           stat_info.LastAccessTime.QuadPart);
   uv__filetime_to_timespec(&statbuf->st_ctim,
-                           file_info.BasicInformation.ChangeTime.QuadPart);
+                           stat_info.ChangeTime.QuadPart);
   uv__filetime_to_timespec(&statbuf->st_mtim,
-                           file_info.BasicInformation.LastWriteTime.QuadPart);
+                           stat_info.LastWriteTime.QuadPart);
   uv__filetime_to_timespec(&statbuf->st_birthtim,
-                           file_info.BasicInformation.CreationTime.QuadPart);
+                           stat_info.CreationTime.QuadPart);
 
-  statbuf->st_ino = file_info.InternalInformation.IndexNumber.QuadPart;
+  statbuf->st_ino = stat_info.FileId.QuadPart;
 
   /* st_blocks contains the on-disk allocation size in 512-byte units. */
   statbuf->st_blocks =
-      (uint64_t) file_info.StandardInformation.AllocationSize.QuadPart >> 9;
+      (uint64_t) stat_info.AllocationSize.QuadPart >> 9;
 
-  statbuf->st_nlink = file_info.StandardInformation.NumberOfLinks;
+  statbuf->st_nlink = stat_info.NumberOfLinks;
 
   /* The st_blksize is supposed to be the 'optimal' number of bytes for reading
    * and writing to the disk. That is, for any definition of 'optimal' - it's
@@ -1840,8 +1926,6 @@ INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
   statbuf->st_uid = 0;
   statbuf->st_rdev = 0;
   statbuf->st_gen = 0;
-
-  return 0;
 }
 
 
@@ -1863,6 +1947,17 @@ INLINE static DWORD fs__stat_impl_from_path(WCHAR* path,
   DWORD flags;
   DWORD ret;
 
+  // If new API exists, try to use it.
+  switch (fs__stat_path(path, statbuf, do_lstat)) {
+    case FS__STAT_PATH_SUCCESS:
+      return 0;
+    case FS__STAT_PATH_ERROR:
+      return GetLastError();
+    case FS__STAT_PATH_TRY_SLOW:
+      break;
+  }
+
+  // If the new API does not exist, use the old API.
   flags = FILE_FLAG_BACKUP_SEMANTICS;
   if (do_lstat)
     flags |= FILE_FLAG_OPEN_REPARSE_POINT;
diff --git a/src/win/winapi.c b/src/win/winapi.c
index 53147b82..4add0e27 100644
--- a/src/win/winapi.c
+++ b/src/win/winapi.c
@@ -48,12 +48,16 @@ sSetWinEventHook pSetWinEventHook;
 /* ws2_32.dll function pointer */
 uv_sGetHostNameW pGetHostNameW;
 
+/* api-ms-win-core-file-l2-1-4.dll function pointer */
+sGetFileInformationByName pGetFileInformationByName;
+
 void uv__winapi_init(void) {
   HMODULE ntdll_module;
   HMODULE powrprof_module;
   HMODULE user32_module;
   HMODULE kernel32_module;
   HMODULE ws2_32_module;
+  HMODULE api_win_core_file_module;
 
   ntdll_module = GetModuleHandleA("ntdll.dll");
   if (ntdll_module == NULL) {
@@ -144,4 +148,10 @@ void uv__winapi_init(void) {
         ws2_32_module,
         "GetHostNameW");
   }
+
+  api_win_core_file_module = GetModuleHandleA("api-ms-win-core-file-l2-1-4.dll");
+  if (api_win_core_file_module != NULL) {
+    pGetFileInformationByName = (sGetFileInformationByName)GetProcAddress(
+        api_win_core_file_module, "GetFileInformationByName");
+  }
 }
diff --git a/src/win/winapi.h b/src/win/winapi.h
index d3449c18..6d948236 100644
--- a/src/win/winapi.h
+++ b/src/win/winapi.h
@@ -4125,6 +4125,24 @@ typedef const UNICODE_STRING *PCUNICODE_STRING;
 # define DEVICE_TYPE DWORD
 #endif
 
+typedef struct _FILE_STAT_BASIC_INFORMATION {
+  LARGE_INTEGER FileId;
+  LARGE_INTEGER CreationTime;
+  LARGE_INTEGER LastAccessTime;
+  LARGE_INTEGER LastWriteTime;
+  LARGE_INTEGER ChangeTime;
+  LARGE_INTEGER AllocationSize;
+  LARGE_INTEGER EndOfFile;
+  ULONG FileAttributes;
+  ULONG ReparseTag;
+  ULONG NumberOfLinks;
+  ULONG DeviceType;
+  ULONG DeviceCharacteristics;
+  ULONG Reserved;
+  FILE_ID_128 FileId128;
+  LARGE_INTEGER VolumeSerialNumber;
+} FILE_STAT_BASIC_INFORMATION;
+
 /* MinGW already has a definition for REPARSE_DATA_BUFFER, but mingw-w64 does
  * not.
  */
@@ -4752,6 +4770,21 @@ typedef struct _TCP_INITIAL_RTO_PARAMETERS {
 # define  SIO_TCP_INITIAL_RTO _WSAIOW(IOC_VENDOR,17)
 #endif
 
+/* from winnt.h */
+typedef enum _FILE_INFO_BY_NAME_CLASS {
+  FileStatByNameInfo,
+  FileStatLxByNameInfo,
+  FileCaseSensitiveByNameInfo,
+  FileStatBasicByNameInfo,
+  MaximumFileInfoByNameClass
+} FILE_INFO_BY_NAME_CLASS;
+
+typedef BOOL(WINAPI* sGetFileInformationByName)(
+    PCWSTR FileName,
+    FILE_INFO_BY_NAME_CLASS FileInformationClass,
+    PVOID FileInfoBuffer,
+    ULONG FileInfoBufferSize);
+
 /* Ntdll function pointers */
 extern sRtlGetVersion pRtlGetVersion;
 extern sRtlNtStatusToDosError pRtlNtStatusToDosError;
@@ -4772,6 +4805,9 @@ extern sPowerRegisterSuspendResumeNotification pPowerRegisterSuspendResumeNotifi
 /* User32.dll function pointer */
 extern sSetWinEventHook pSetWinEventHook;
 
+/* api-ms-win-core-file-l2-1-4.dll function pointers */
+extern sGetFileInformationByName pGetFileInformationByName;
+
 /* ws2_32.dll function pointer */
 /* mingw doesn't have this definition, so let's declare it here locally */
 typedef int (WINAPI *uv_sGetHostNameW)