cache.py 文件源码

def __init__(self, folder):
            self.folder = folder
            # Check the best way to do atomic file replacement.
            if sys.version_info >= (3, 3):
                self.replace = os.replace
            elif sys.platform == "win32":
                import ctypes
                from ctypes import wintypes
                ReplaceFile = ctypes.windll.kernel32.ReplaceFileW
                ReplaceFile.restype = wintypes.BOOL
                ReplaceFile.argtypes = [
                    wintypes.LPWSTR,
                    wintypes.LPWSTR,
                    wintypes.LPWSTR,
                    wintypes.DWORD,
                    wintypes.LPVOID,
                    wintypes.LPVOID,
                    ]

                def replace_windows(src, dst):
                    if not ReplaceFile(dst, src, None, 0, 0, 0):
                        os.rename(src, dst)

                self.replace = replace_windows
            else:
                # POSIX rename() is always atomic
                self.replace = os.rename