hio.core.wms.wmsing
===================

.. py:module:: hio.core.wms.wmsing

.. autoapi-nested-parse::

   hio.core.wms.wmsing Module

   WinMailSlots as datagram transport





Module Contents
---------------

.. py:class:: Peer(*, umask=None, bc=None, bs=None, wl=None, reopen=False, clear=True, filed=False, extensioned=True, **kwa)

   Bases: :py:obj:`hio.base.filing.Filer`


   Class to manage reliable datagram transport on Windows using Mailslots
   instead of unix domain sockets. WinMailSlot (wms)

   Because win-mail-slots (wms) are reliable no need for retry timer.
   Because win-mail-slots do not attach the source address we have to
   embed the source address in the memogram header. So we need a new memogram
   header code for wms as reliable transport replacement for uxd on Windows.



   Inherited Class Attributes:
       HeadDirPath (str): default abs dir path head such as "/usr/local/var"
       TailDirPath (str): default rel dir path tail when using head
       CleanTailDirPath (str): default rel dir path tail when creating clean
       AltHeadDirPath (str): default alt dir path head such as "~" as fallback when desired head not permitted.
       AltTailDirPath (str): default alt rel dir path tail as fallback when using alt head.
       AltCleanTailDirPath (str): default alt rel path tail when creating clean
       TempHeadDir (str): default temp abs dir path head such as "/tmp"
       TempPrefix (str): default rel dir path prefix when using temp head
       TempSuffix (str): default rel dir path suffix when using temp head and tail
       Perm (int): explicit default octal perms such as 0o1700
       Mode (str): open mode such as "r+"
       Fext (str): default file extension such as "text" for "fname.text"

   Inherited Attributes:
       name (str): unique path component used in directory or file path name
       base (str): another unique path component inserted before name
       temp (bool): True means use TempHeadDir in /tmp directory
       headDirPath (str): head directory path
       path (str or None):  full directory or file path once created else None
       perm (int):  numeric os permissions for directory and/or file(s)
       filed (bool): True means .path ends in file; False means .path ends in directory.
       mode (str): file open mode if filed
       fext (str): file extension if filed
       file (File or None): File instance when filed and created.
       opened (bool): True means directory path, uxd file, and socket are created and opened; False otherwise.

   Class Attributes:
       Umask (int): octal default umask permissions such as 0o022
       MaxGramSize (int): max bytes in in datagram for this transport
       BufSize (int): used to set buffer size for transport datagram buffers


   .. attribute:: umask

      permission mask for uxd file, usually octal 0o022;
      .umask is applied after .perm is set if any.

      :type: int

   .. attribute:: bc

      count of transport buffers of MaxGramSize

      :type: int or None

   .. attribute:: bs

      buffer size of transport buffers. When .bc then .bs is
      calculated by multiplying (.bs = .bc * .MaxGramSize). When .bc is
      None then .bs is provided value or default .BufSize.

      :type: int

   .. attribute:: wl

      instance ref for debug logging of over the wire tx and rx

      :type: WireLog

   .. attribute:: ls

      local slot of this Peer

      :type: socket.socket


   .. py:method:: open()

      Opens mailslot in nonblocking mode




   .. py:method:: reopen()

      Clear the ms and reopen



   .. py:method:: close()

      Close the mailslot



   .. py:method:: receive()

      Perform a non-blocking read on the mailslot

      :returns: (data, sa). If no data, returns (b'', None), but always
                returns a tuple with 2 elements.
      :rtype: tuple

      .. rubric:: Notes

      win32file.ReadFile returns a tuple: (errcode, data).



   .. py:method:: send(data, dest)

      Perform a non-blocking write on the mailslot
      data is string in python2 and bytes in python3
      dest is destination mailslot path

      :param data: to send
      :type data: bytes
      :param dest: destination mailslot
      :type dest: Mailslot