gh-88745: Add _winapi.CopyFile2 and update shutil.copy2 to use it (GH-105055)

(cherry picked from commit cda1bd3) Co-authored-by: Steve Dower <steve.dower@python.org>

Author: miss-islington

Doc/data/python3.12.abi

@@ -404,6 +404,7 @@ struct _Py_global_strings {
  STRUCT_FOR_ID(exc_value)
  STRUCT_FOR_ID(excepthook)
  STRUCT_FOR_ID(exception)
+ STRUCT_FOR_ID(existing_file_name)
  STRUCT_FOR_ID(exp)
  STRUCT_FOR_ID(extend)
  STRUCT_FOR_ID(extra_tokens)
@@ -556,6 +557,7 @@ struct _Py_global_strings {
  STRUCT_FOR_ID(namespaces)
  STRUCT_FOR_ID(narg)
  STRUCT_FOR_ID(ndigits)
+ STRUCT_FOR_ID(new_file_name)
  STRUCT_FOR_ID(new_limit)
  STRUCT_FOR_ID(newline)
  STRUCT_FOR_ID(newlines)
@@ -610,6 +612,7 @@ struct _Py_global_strings {
  STRUCT_FOR_ID(priority)
  STRUCT_FOR_ID(progress)
  STRUCT_FOR_ID(progress_handler)
+ STRUCT_FOR_ID(progress_routine)
  STRUCT_FOR_ID(proto)
  STRUCT_FOR_ID(protocol)
  STRUCT_FOR_ID(ps1)

Include/internal/pycore_global_objects_fini_generated.h

@@ -42,6 +42,8 @@
 
 if sys.platform == 'win32':
  import _winapi
+else:
+ _winapi = None
 
 COPY_BUFSIZE = 1024 * 1024 if _WINDOWS else 64 * 1024
 # This should never be removed, see rationale in:
@@ -435,6 +437,29 @@ def copy2(src, dst, *, follow_symlinks=True):
  """
  if os.path.isdir(dst):
  dst = os.path.join(dst, os.path.basename(src))
+
+ if hasattr(_winapi, "CopyFile2"):
+ src_ = os.fsdecode(src)
+ dst_ = os.fsdecode(dst)
+ flags = _winapi.COPY_FILE_ALLOW_DECRYPTED_DESTINATION # for compat
+ if not follow_symlinks:
+ flags |= _winapi.COPY_FILE_COPY_SYMLINK
+ try:
+ _winapi.CopyFile2(src_, dst_, flags)
+ return dst
+ except OSError as exc:
+ if (exc.winerror == _winapi.ERROR_PRIVILEGE_NOT_HELD
+ and not follow_symlinks):
+ # Likely encountered a symlink we aren't allowed to create.
+ # Fall back on the old code
+ pass
+ elif exc.winerror == _winapi.ERROR_ACCESS_DENIED:
+ # Possibly encountered a hidden or readonly file we can't
+ # overwrite. Fall back on old code
+ pass
+ else:
+ raise
+
  copyfile(src, dst, follow_symlinks=follow_symlinks)
  copystat(src, dst, follow_symlinks=follow_symlinks)
  return dst

Include/internal/pycore_global_strings.h

@@ -0,0 +1,3 @@
+Improve performance of :func:`shutil.copy2` by using the operating system's
+``CopyFile2`` function. This may result in subtle changes to metadata copied
+along with some files, bringing them in line with normal OS behavior.

Include/internal/pycore_runtime_init_generated.h

@@ -1947,6 +1947,7 @@ _winapi_GetFileType_impl(PyObject *module, HANDLE handle)
  return result;
 }
 
+
 /*[clinic input]
 _winapi._mimetypes_read_windows_registry
 
@@ -2075,6 +2076,67 @@ _winapi_NeedCurrentDirectoryForExePath_impl(PyObject *module,
  return result;
 }
 
+
+/*[clinic input]
+_winapi.CopyFile2
+
+ existing_file_name: LPCWSTR
+ new_file_name: LPCWSTR
+ flags: DWORD
+ progress_routine: object = None
+
+Copies a file from one name to a new name.
+
+This is implemented using the CopyFile2 API, which preserves all stat
+and metadata information apart from security attributes.
+
+progress_routine is reserved for future use, but is currently not
+implemented. Its value is ignored.
+[clinic start generated code]*/
+
+static PyObject *
+_winapi_CopyFile2_impl(PyObject *module, LPCWSTR existing_file_name,
+ LPCWSTR new_file_name, DWORD flags,
+ PyObject *progress_routine)
+/*[clinic end generated code: output=43d960d9df73d984 input=fb976b8d1492d130]*/
+{
+ HRESULT hr;
+ COPYFILE2_EXTENDED_PARAMETERS params = { sizeof(COPYFILE2_EXTENDED_PARAMETERS) };
+
+ if (PySys_Audit("_winapi.CopyFile2", "uuI",
+ existing_file_name, new_file_name, flags) < 0) {
+ return NULL;
+ }
+
+ params.dwCopyFlags = flags;
+ /* For future implementation. We ignore the value for now so that
+ users only have to test for 'CopyFile2' existing and not whether
+ the additional parameter exists.
+ if (progress_routine != Py_None) {
+ params.pProgressRoutine = _winapi_CopyFile2ProgressRoutine;
+ params.pvCallbackContext = Py_NewRef(progress_routine);
+ }
+ */
+ Py_BEGIN_ALLOW_THREADS;
+ hr = CopyFile2(existing_file_name, new_file_name, &params);
+ Py_END_ALLOW_THREADS;
+ /* For future implementation.
+ if (progress_routine != Py_None) {
+ Py_DECREF(progress_routine);
+ }
+ */
+ if (FAILED(hr)) {
+ if ((hr & 0xFFFF0000) == 0x80070000) {
+ PyErr_SetFromWindowsErr(hr & 0xFFFF);
+ } else {
+ PyErr_SetFromWindowsErr(hr);
+ }
+ return NULL;
+ }
+ Py_RETURN_NONE;
+}
+
+
 static PyMethodDef winapi_functions[] = {
  _WINAPI_CLOSEHANDLE_METHODDEF
  _WINAPI_CONNECTNAMEDPIPE_METHODDEF
@@ -2110,6 +2172,7 @@ static PyMethodDef winapi_functions[] = {
  _WINAPI_GETFILETYPE_METHODDEF
  _WINAPI__MIMETYPES_READ_WINDOWS_REGISTRY_METHODDEF
  _WINAPI_NEEDCURRENTDIRECTORYFOREXEPATH_METHODDEF
+ _WINAPI_COPYFILE2_METHODDEF
  {NULL, NULL}
 };
 
@@ -2146,6 +2209,7 @@ static int winapi_exec(PyObject *m)
  WINAPI_CONSTANT(F_DWORD, CREATE_NEW_PROCESS_GROUP);
  WINAPI_CONSTANT(F_DWORD, DUPLICATE_SAME_ACCESS);
  WINAPI_CONSTANT(F_DWORD, DUPLICATE_CLOSE_SOURCE);
+ WINAPI_CONSTANT(F_DWORD, ERROR_ACCESS_DENIED);
  WINAPI_CONSTANT(F_DWORD, ERROR_ALREADY_EXISTS);
  WINAPI_CONSTANT(F_DWORD, ERROR_BROKEN_PIPE);
  WINAPI_CONSTANT(F_DWORD, ERROR_IO_PENDING);
@@ -2159,6 +2223,7 @@ static int winapi_exec(PyObject *m)
  WINAPI_CONSTANT(F_DWORD, ERROR_OPERATION_ABORTED);
  WINAPI_CONSTANT(F_DWORD, ERROR_PIPE_BUSY);
  WINAPI_CONSTANT(F_DWORD, ERROR_PIPE_CONNECTED);
+ WINAPI_CONSTANT(F_DWORD, ERROR_PRIVILEGE_NOT_HELD);
  WINAPI_CONSTANT(F_DWORD, ERROR_SEM_TIMEOUT);
  WINAPI_CONSTANT(F_DWORD, FILE_FLAG_FIRST_PIPE_INSTANCE);
  WINAPI_CONSTANT(F_DWORD, FILE_FLAG_OVERLAPPED);
@@ -2252,6 +2317,34 @@ static int winapi_exec(PyObject *m)
  WINAPI_CONSTANT(F_DWORD, LCMAP_TRADITIONAL_CHINESE);
  WINAPI_CONSTANT(F_DWORD, LCMAP_UPPERCASE);
 
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_ALLOW_DECRYPTED_DESTINATION);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_COPY_SYMLINK);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_FAIL_IF_EXISTS);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_NO_BUFFERING);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_NO_OFFLOAD);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_OPEN_SOURCE_FOR_WRITE);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_RESTARTABLE);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_REQUEST_SECURITY_PRIVILEGES);
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_RESUME_FROM_PAUSE);
+#ifndef COPY_FILE_REQUEST_COMPRESSED_TRAFFIC
+ // Only defined in newer WinSDKs
+ #define COPY_FILE_REQUEST_COMPRESSED_TRAFFIC 0x10000000
+#endif
+ WINAPI_CONSTANT(F_DWORD, COPY_FILE_REQUEST_COMPRESSED_TRAFFIC);
+
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_CALLBACK_CHUNK_STARTED);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_CALLBACK_CHUNK_FINISHED);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_CALLBACK_STREAM_STARTED);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_CALLBACK_STREAM_FINISHED);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_CALLBACK_POLL_CONTINUE);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_CALLBACK_ERROR);
+
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_PROGRESS_CONTINUE);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_PROGRESS_CANCEL);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_PROGRESS_STOP);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_PROGRESS_QUIET);
+ WINAPI_CONSTANT(F_DWORD, COPYFILE2_PROGRESS_PAUSE);
+
  WINAPI_CONSTANT("i", NULL);
 
  return 0;