From 2db58930a6f8c955c4d437657bd07e2939a705f2 Mon Sep 17 00:00:00 2001 From: James Taylor Date: Sun, 16 Jun 2019 16:16:03 -0700 Subject: Convert watch page to flask framework --- python/werkzeug/posixemulation.py | 117 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 python/werkzeug/posixemulation.py (limited to 'python/werkzeug/posixemulation.py') diff --git a/python/werkzeug/posixemulation.py b/python/werkzeug/posixemulation.py new file mode 100644 index 0000000..696b456 --- /dev/null +++ b/python/werkzeug/posixemulation.py @@ -0,0 +1,117 @@ +# -*- coding: utf-8 -*- +r""" + werkzeug.posixemulation + ~~~~~~~~~~~~~~~~~~~~~~~ + + Provides a POSIX emulation for some features that are relevant to + web applications. The main purpose is to simplify support for + systems such as Windows NT that are not 100% POSIX compatible. + + Currently this only implements a :func:`rename` function that + follows POSIX semantics. Eg: if the target file already exists it + will be replaced without asking. + + This module was introduced in 0.6.1 and is not a public interface. + It might become one in later versions of Werkzeug. + + :copyright: 2007 Pallets + :license: BSD-3-Clause +""" +import errno +import os +import random +import sys +import time + +from ._compat import to_unicode +from .filesystem import get_filesystem_encoding + +can_rename_open_file = False + +if os.name == "nt": + try: + import ctypes + + _MOVEFILE_REPLACE_EXISTING = 0x1 + _MOVEFILE_WRITE_THROUGH = 0x8 + _MoveFileEx = ctypes.windll.kernel32.MoveFileExW + + def _rename(src, dst): + src = to_unicode(src, get_filesystem_encoding()) + dst = to_unicode(dst, get_filesystem_encoding()) + if _rename_atomic(src, dst): + return True + retry = 0 + rv = False + while not rv and retry < 100: + rv = _MoveFileEx( + src, dst, _MOVEFILE_REPLACE_EXISTING | _MOVEFILE_WRITE_THROUGH + ) + if not rv: + time.sleep(0.001) + retry += 1 + return rv + + # new in Vista and Windows Server 2008 + _CreateTransaction = ctypes.windll.ktmw32.CreateTransaction + _CommitTransaction = ctypes.windll.ktmw32.CommitTransaction + _MoveFileTransacted = ctypes.windll.kernel32.MoveFileTransactedW + _CloseHandle = ctypes.windll.kernel32.CloseHandle + can_rename_open_file = True + + def _rename_atomic(src, dst): + ta = _CreateTransaction(None, 0, 0, 0, 0, 1000, "Werkzeug rename") + if ta == -1: + return False + try: + retry = 0 + rv = False + while not rv and retry < 100: + rv = _MoveFileTransacted( + src, + dst, + None, + None, + _MOVEFILE_REPLACE_EXISTING | _MOVEFILE_WRITE_THROUGH, + ta, + ) + if rv: + rv = _CommitTransaction(ta) + break + else: + time.sleep(0.001) + retry += 1 + return rv + finally: + _CloseHandle(ta) + + except Exception: + + def _rename(src, dst): + return False + + def _rename_atomic(src, dst): + return False + + def rename(src, dst): + # Try atomic or pseudo-atomic rename + if _rename(src, dst): + return + # Fall back to "move away and replace" + try: + os.rename(src, dst) + except OSError as e: + if e.errno != errno.EEXIST: + raise + old = "%s-%08x" % (dst, random.randint(0, sys.maxsize)) + os.rename(dst, old) + os.rename(src, dst) + try: + os.unlink(old) + except Exception: + pass + + +else: + rename = os.rename + can_rename_open_file = True -- cgit v1.2.3