Python locks.unlock方法代碼示例

# 需要導入模塊: from django.core.files import locks [as 別名]
# 或者: from django.core.files.locks import unlock [as 別名]
def file_move_safe(old_file_name, new_file_name, chunk_size=1024 * 64, allow_overwrite=False):
    """
    Moves a file from one location to another in the safest way possible.

    First, tries ``os.rename``, which is simple but will break across filesystems.
    If that fails, streams manually from one file to another in pure Python.

    If the destination file exists and ``allow_overwrite`` is ``False``, this
    function will throw an ``IOError``.
    """

    # There's no reason to move if we don't have to.
    if _samefile(old_file_name, new_file_name):
        return

    try:
        # If the destination file exists and allow_overwrite is False then raise an IOError
        if not allow_overwrite and os.access(new_file_name, os.F_OK):
            raise IOError("Destination file %s exists and allow_overwrite is False" % new_file_name)

        os.rename(old_file_name, new_file_name)
        return
    except OSError:
        # This will happen with os.rename if moving to another filesystem
        # or when moving opened files on certain operating systems
        pass

    # first open the old file, so that it won't go away
    with open(old_file_name, 'rb') as old_file:
        # now open the new file, not forgetting allow_overwrite
        fd = os.open(new_file_name, (os.O_WRONLY | os.O_CREAT | getattr(os, 'O_BINARY', 0) |
                                     (os.O_EXCL if not allow_overwrite else 0)))
        try:
            locks.lock(fd, locks.LOCK_EX)
            current_chunk = None
            while current_chunk != b'':
                current_chunk = old_file.read(chunk_size)
                os.write(fd, current_chunk)
        finally:
            locks.unlock(fd)
            os.close(fd)
    copystat(old_file_name, new_file_name)

    try:
        os.remove(old_file_name)
    except OSError as e:
        # Certain operating systems (Cygwin and Windows)
        # fail when deleting opened files, ignore it.  (For the
        # systems where this happens, temporary files will be auto-deleted
        # on close anyway.)
        if getattr(e, 'winerror', 0) != 32 and getattr(e, 'errno', 0) != 13:
            raise 

# 需要導入模塊: from django.core.files import locks [as 別名]
# 或者: from django.core.files.locks import unlock [as 別名]
def file_move_safe(old_file_name, new_file_name, chunk_size = 1024*64, allow_overwrite=False):
    """
    Moves a file from one location to another in the safest way possible.

    First, tries ``os.rename``, which is simple but will break across filesystems.
    If that fails, streams manually from one file to another in pure Python.

    If the destination file exists and ``allow_overwrite`` is ``False``, this
    function will throw an ``IOError``.
    """

    # There's no reason to move if we don't have to.
    if _samefile(old_file_name, new_file_name):
        return

    try:
        os.rename(old_file_name, new_file_name)
        return
    except OSError:
        # This will happen with os.rename if moving to another filesystem
        # or when moving opened files on certain operating systems
        pass

    # first open the old file, so that it won't go away
    with open(old_file_name, 'rb') as old_file:
        # now open the new file, not forgetting allow_overwrite
        fd = os.open(new_file_name, os.O_WRONLY | os.O_CREAT | getattr(os, 'O_BINARY', 0) |
                                    (not allow_overwrite and os.O_EXCL or 0))
        try:
            locks.lock(fd, locks.LOCK_EX)
            current_chunk = None
            while current_chunk != b'':
                current_chunk = old_file.read(chunk_size)
                os.write(fd, current_chunk)
        finally:
            locks.unlock(fd)
            os.close(fd)
    copystat(old_file_name, new_file_name)

    try:
        os.remove(old_file_name)
    except OSError as e:
        # Certain operating systems (Cygwin and Windows) 
        # fail when deleting opened files, ignore it.  (For the 
        # systems where this happens, temporary files will be auto-deleted
        # on close anyway.)
        if getattr(e, 'winerror', 0) != 32 and getattr(e, 'errno', 0) != 13:
            raise 

# 需要導入模塊: from django.core.files import locks [as 別名]
# 或者: from django.core.files.locks import unlock [as 別名]
def _save(self, name, content):
        full_path = self.path(name)

        directory = os.path.dirname(full_path)
        if not os.path.exists(directory):
            os.makedirs(directory)
        elif not os.path.isdir(directory):
            raise IOError("%s exists and is not a directory." % directory)

        # There's a potential race condition between get_available_name and
        # saving the file; it's possible that two threads might return the
        # same name, at which point all sorts of fun happens. So we need to
        # try to create the file, but if it already exists we have to go back
        # to get_available_name() and try again.

        while True:
            try:
                # This file has a file path that we can move.
                if hasattr(content, 'temporary_file_path'):
                    file_move_safe(content.temporary_file_path(), full_path)
                    content.close()

                # This is a normal uploadedfile that we can stream.
                else:
                    # This fun binary flag incantation makes os.open throw an
                    # OSError if the file already exists before we open it.
                    fd = os.open(full_path, os.O_WRONLY | os.O_CREAT | os.O_EXCL | getattr(os, 'O_BINARY', 0))
                    try:
                        locks.lock(fd, locks.LOCK_EX)
                        for chunk in content.chunks():
                            os.write(fd, chunk)
                            # CHANGED: This un-hangs us long enough to keep things rolling.
                            eventlet.sleep(0)
                    finally:
                        locks.unlock(fd)
                        os.close(fd)
            except OSError, e:
                if e.errno == errno.EEXIST:
                    # Ooops, the file exists. We need a new file name.
                    name = self.get_available_name(name)
                    full_path = self.path(name)
                else:
                    raise
            else:
                # OK, the file save worked. Break out of the loop.
                break