gh-102765: Update ntpath.isdir/isfile/islink/exists to use GetFileInformationByName when available (GH-103485)

2 files changed, 209 insertions, 118 deletions

diff --git a/Include/internal/pycore_fileutils_windows.h b/Include/internal/pycore_fileutils_windows.h
index 9bc7feb..e804d38 100644
--- a/Include/internal/pycore_fileutils_windows.h
+++ b/Include/internal/pycore_fileutils_windows.h
@@ -75,6 +75,24 @@ static inline BOOL _Py_GetFileInformationByName(
     return GetFileInformationByName(FileName, FileInformationClass, FileInfoBuffer, FileInfoBufferSize);
 }
 
+static inline BOOL _Py_GetFileInformationByName_ErrorIsTrustworthy(int error)
+{
+    switch(error) {
+        case ERROR_FILE_NOT_FOUND:
+        case ERROR_PATH_NOT_FOUND:
+        case ERROR_NOT_READY:
+        case ERROR_BAD_NET_NAME:
+        case ERROR_BAD_NETPATH:
+        case ERROR_BAD_PATHNAME:
+        case ERROR_INVALID_NAME:
+        case ERROR_FILENAME_EXCED_RANGE:
+            return TRUE;
+        case ERROR_NOT_SUPPORTED:
+            return FALSE;
+    }
+    return FALSE;
+}
+
 #endif
 
 #endif
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index dd15010..dcb5e7a 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -4789,6 +4789,8 @@ os__path_isdir_impl(PyObject *module, PyObject *path)
     FILE_BASIC_INFO info;
     path_t _path = PATH_T_INITIALIZE("isdir", "path", 0, 1);
     int result;
+    BOOL slow_path = TRUE;
+    FILE_STAT_BASIC_INFORMATION statInfo;
 
     if (!path_converter(path, &_path)) {
         path_cleanup(&_path);
@@ -4800,43 +4802,60 @@ os__path_isdir_impl(PyObject *module, PyObject *path)
     }
 
     Py_BEGIN_ALLOW_THREADS
-    if (_path.fd != -1) {
-        hfile = _Py_get_osfhandle_noraise(_path.fd);
-        close_file = FALSE;
-    }
-    else {
-        hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
-                            OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
+    if (_path.wide) {    
+        if (_Py_GetFileInformationByName(_path.wide, FileStatBasicByNameInfo,
+                                         &statInfo, sizeof(statInfo))) {
+            if (!(statInfo.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+                slow_path = FALSE;
+                result = statInfo.FileAttributes & FILE_ATTRIBUTE_DIRECTORY;
+            } else if (!(statInfo.FileAttributes & FILE_ATTRIBUTE_DIRECTORY)) {
+                slow_path = FALSE;
+                result = 0;
+            }
+        } else if (_Py_GetFileInformationByName_ErrorIsTrustworthy(GetLastError())) {
+                    slow_path = FALSE;
+                    result = 0;
+        }
     }
-    if (hfile != INVALID_HANDLE_VALUE) {
-        if (GetFileInformationByHandleEx(hfile, FileBasicInfo, &info,
-                                         sizeof(info)))
-        {
-            result = info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY;
+    if (slow_path) {
+        if (_path.fd != -1) {
+            hfile = _Py_get_osfhandle_noraise(_path.fd);
+            close_file = FALSE;
         }
         else {
-            result = 0;
+            hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
+                                OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
         }
-        if (close_file) {
-            CloseHandle(hfile);
-        }
-    }
-    else {
-        STRUCT_STAT st;
-        switch (GetLastError()) {
-        case ERROR_ACCESS_DENIED:
-        case ERROR_SHARING_VIOLATION:
-        case ERROR_CANT_ACCESS_FILE:
-        case ERROR_INVALID_PARAMETER:
-            if (STAT(_path.wide, &st)) {
-                result = 0;
+        if (hfile != INVALID_HANDLE_VALUE) {
+            if (GetFileInformationByHandleEx(hfile, FileBasicInfo, &info,
+                                            sizeof(info)))
+            {
+                result = info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY;
             }
             else {
-                result = S_ISDIR(st.st_mode);
+                result = 0;
+            }
+            if (close_file) {
+                CloseHandle(hfile);
+            }
+        }
+        else {
+            STRUCT_STAT st;
+            switch (GetLastError()) {
+            case ERROR_ACCESS_DENIED:
+            case ERROR_SHARING_VIOLATION:
+            case ERROR_CANT_ACCESS_FILE:
+            case ERROR_INVALID_PARAMETER:
+                if (STAT(_path.wide, &st)) {
+                    result = 0;
+                }
+                else {
+                    result = S_ISDIR(st.st_mode);
+                }
+                break;
+            default:
+                result = 0;
             }
-            break;
-        default:
-            result = 0;
         }
     }
     Py_END_ALLOW_THREADS
@@ -4867,6 +4886,8 @@ os__path_isfile_impl(PyObject *module, PyObject *path)
     FILE_BASIC_INFO info;
     path_t _path = PATH_T_INITIALIZE("isfile", "path", 0, 1);
     int result;
+    BOOL slow_path = TRUE;
+    FILE_STAT_BASIC_INFORMATION statInfo;
 
     if (!path_converter(path, &_path)) {
         path_cleanup(&_path);
@@ -4878,43 +4899,60 @@ os__path_isfile_impl(PyObject *module, PyObject *path)
     }
 
     Py_BEGIN_ALLOW_THREADS
-    if (_path.fd != -1) {
-        hfile = _Py_get_osfhandle_noraise(_path.fd);
-        close_file = FALSE;
-    }
-    else {
-        hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
-                            OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
+    if (_path.wide) {    
+        if (_Py_GetFileInformationByName(_path.wide, FileStatBasicByNameInfo,
+                                         &statInfo, sizeof(statInfo))) {
+            if (!(statInfo.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+                slow_path = FALSE;
+                result = !(statInfo.FileAttributes & FILE_ATTRIBUTE_DIRECTORY);
+            } else if (statInfo.FileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+                slow_path = FALSE;
+                result = 0;
+            }
+        } else if (_Py_GetFileInformationByName_ErrorIsTrustworthy(GetLastError())) {
+                    slow_path = FALSE;
+                    result = 0;
+        }
     }
-    if (hfile != INVALID_HANDLE_VALUE) {
-        if (GetFileInformationByHandleEx(hfile, FileBasicInfo, &info,
-                                         sizeof(info)))
-        {
-            result = !(info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY);
+    if (slow_path) {
+        if (_path.fd != -1) {
+            hfile = _Py_get_osfhandle_noraise(_path.fd);
+            close_file = FALSE;
         }
         else {
-            result = 0;
-        }
-        if (close_file) {
-            CloseHandle(hfile);
+            hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
+                                OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
         }
-    }
-    else {
-        STRUCT_STAT st;
-        switch (GetLastError()) {
-        case ERROR_ACCESS_DENIED:
-        case ERROR_SHARING_VIOLATION:
-        case ERROR_CANT_ACCESS_FILE:
-        case ERROR_INVALID_PARAMETER:
-            if (STAT(_path.wide, &st)) {
-                result = 0;
+        if (hfile != INVALID_HANDLE_VALUE) {
+            if (GetFileInformationByHandleEx(hfile, FileBasicInfo, &info,
+                                            sizeof(info)))
+            {
+                result = !(info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY);
             }
             else {
-                result = S_ISREG(st.st_mode);
+                result = 0;
+            }
+            if (close_file) {
+                CloseHandle(hfile);
+            }
+        }
+        else {
+            STRUCT_STAT st;
+            switch (GetLastError()) {
+            case ERROR_ACCESS_DENIED:
+            case ERROR_SHARING_VIOLATION:
+            case ERROR_CANT_ACCESS_FILE:
+            case ERROR_INVALID_PARAMETER:
+                if (STAT(_path.wide, &st)) {
+                    result = 0;
+                }
+                else {
+                    result = S_ISREG(st.st_mode);
+                }
+                break;
+            default:
+                result = 0;
             }
-            break;
-        default:
-            result = 0;
         }
     }
     Py_END_ALLOW_THREADS
@@ -4944,6 +4982,8 @@ os__path_exists_impl(PyObject *module, PyObject *path)
     BOOL close_file = TRUE;
     path_t _path = PATH_T_INITIALIZE("exists", "path", 0, 1);
     int result;
+    BOOL slow_path = TRUE;
+    FILE_STAT_BASIC_INFORMATION statInfo;
 
     if (!path_converter(path, &_path)) {
         path_cleanup(&_path);
@@ -4955,36 +4995,50 @@ os__path_exists_impl(PyObject *module, PyObject *path)
     }
 
     Py_BEGIN_ALLOW_THREADS
-    if (_path.fd != -1) {
-        hfile = _Py_get_osfhandle_noraise(_path.fd);
-        close_file = FALSE;
-    }
-    else {
-        hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
-                            OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
-    }
-    if (hfile != INVALID_HANDLE_VALUE) {
-        result = 1;
-        if (close_file) {
-            CloseHandle(hfile);
+    if (_path.wide) {    
+        if (_Py_GetFileInformationByName(_path.wide, FileStatBasicByNameInfo,
+                                         &statInfo, sizeof(statInfo))) {
+            if (!(statInfo.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+                slow_path = FALSE;
+                result = 1;
+            }
+        } else if (_Py_GetFileInformationByName_ErrorIsTrustworthy(GetLastError())) {
+                    slow_path = FALSE;
+                    result = 0;
         }
     }
-    else {
-        STRUCT_STAT st;
-        switch (GetLastError()) {
-        case ERROR_ACCESS_DENIED:
-        case ERROR_SHARING_VIOLATION:
-        case ERROR_CANT_ACCESS_FILE:
-        case ERROR_INVALID_PARAMETER:
-            if (STAT(_path.wide, &st)) {
-                result = 0;
+    if (slow_path) {
+        if (_path.fd != -1) {
+            hfile = _Py_get_osfhandle_noraise(_path.fd);
+            close_file = FALSE;
+        }
+        else {
+            hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
+                                OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
+        }
+        if (hfile != INVALID_HANDLE_VALUE) {
+            result = 1;
+            if (close_file) {
+                CloseHandle(hfile);
             }
-            else {
-                result = 1;
+        }
+        else {
+            STRUCT_STAT st;
+            switch (GetLastError()) {
+            case ERROR_ACCESS_DENIED:
+            case ERROR_SHARING_VIOLATION:
+            case ERROR_CANT_ACCESS_FILE:
+            case ERROR_INVALID_PARAMETER:
+                if (STAT(_path.wide, &st)) {
+                    result = 0;
+                }
+                else {
+                    result = 1;
+                }
+                break;
+            default:
+                result = 0;
             }
-            break;
-        default:
-            result = 0;
         }
     }
     Py_END_ALLOW_THREADS
@@ -5015,6 +5069,8 @@ os__path_islink_impl(PyObject *module, PyObject *path)
     FILE_ATTRIBUTE_TAG_INFO info;
     path_t _path = PATH_T_INITIALIZE("islink", "path", 0, 1);
     int result;
+    BOOL slow_path = TRUE;
+    FILE_STAT_BASIC_INFORMATION statInfo;
 
     if (!path_converter(path, &_path)) {
         path_cleanup(&_path);
@@ -5026,45 +5082,62 @@ os__path_islink_impl(PyObject *module, PyObject *path)
     }
 
     Py_BEGIN_ALLOW_THREADS
-    if (_path.fd != -1) {
-        hfile = _Py_get_osfhandle_noraise(_path.fd);
-        close_file = FALSE;
+    if (_path.wide) {    
+        if (_Py_GetFileInformationByName(_path.wide, FileStatBasicByNameInfo,
+                                         &statInfo, sizeof(statInfo))) {
+            slow_path = FALSE;
+            if (statInfo.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
+                result = (statInfo.ReparseTag == IO_REPARSE_TAG_SYMLINK);
+            }
+            else {
+                result = 0;
+            }
+        } else if (_Py_GetFileInformationByName_ErrorIsTrustworthy(GetLastError())) {
+                    slow_path = FALSE;
+                    result = 0;
+        }
     }
-    else {
-        hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
-                            OPEN_EXISTING,
-                            FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS,
-                            NULL);
-    }
-    if (hfile != INVALID_HANDLE_VALUE) {
-        if (GetFileInformationByHandleEx(hfile, FileAttributeTagInfo, &info,
-                                         sizeof(info)))
-        {
-            result = (info.ReparseTag == IO_REPARSE_TAG_SYMLINK);
+    if (slow_path) {
+        if (_path.fd != -1) {
+            hfile = _Py_get_osfhandle_noraise(_path.fd);
+            close_file = FALSE;
         }
         else {
-            result = 0;
+            hfile = CreateFileW(_path.wide, FILE_READ_ATTRIBUTES, 0, NULL,
+                                OPEN_EXISTING,
+                                FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS,
+                                NULL);
         }
-        if (close_file) {
-            CloseHandle(hfile);
-        }
-    }
-    else {
-        STRUCT_STAT st;
-        switch (GetLastError()) {
-        case ERROR_ACCESS_DENIED:
-        case ERROR_SHARING_VIOLATION:
-        case ERROR_CANT_ACCESS_FILE:
-        case ERROR_INVALID_PARAMETER:
-            if (LSTAT(_path.wide, &st)) {
-                result = 0;
+        if (hfile != INVALID_HANDLE_VALUE) {
+            if (GetFileInformationByHandleEx(hfile, FileAttributeTagInfo, &info,
+                                            sizeof(info)))
+            {
+                result = (info.ReparseTag == IO_REPARSE_TAG_SYMLINK);
             }
             else {
-                result = S_ISLNK(st.st_mode);
+                result = 0;
+            }
+            if (close_file) {
+                CloseHandle(hfile);
+            }
+        }
+        else {
+            STRUCT_STAT st;
+            switch (GetLastError()) {
+            case ERROR_ACCESS_DENIED:
+            case ERROR_SHARING_VIOLATION:
+            case ERROR_CANT_ACCESS_FILE:
+            case ERROR_INVALID_PARAMETER:
+                if (LSTAT(_path.wide, &st)) {
+                    result = 0;
+                }
+                else {
+                    result = S_ISLNK(st.st_mode);
+                }
+                break;
+            default:
+                result = 0;
             }
-            break;
-        default:
-            result = 0;
         }
     }
     Py_END_ALLOW_THREADS