# server.py - inotify common protocol code

#

# Copyright 2006, 2007, 2008 Bryan O'Sullivan <bos@serpentine.com>

# Copyright 2007, 2008 Brendan Cully <brendan@kublai.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2, incorporated herein by reference.

import cStringIO, socket, struct

"""

  Protocol between inotify clients and server:

  Client sending query:

  1) send protocol version number

  2) send query type (string, 4 letters long)

  3) send query parameters:

     - For STAT, N+1 \0-separated strings:

        1) N different names that need checking

        2) 1 string containing all the status types to match

     - No parameter needed for DBUG

  Server sending query answer:

  1) send protocol version number

  2) send query type

  3) send struct.pack'ed headers describing the length of the content:

      e.g. for STAT, receive 8 integers describing the length of the

      8 \0-separated string lists ( one list for each lmar!?ic status type )

"""

version = 2

resphdrfmts = {

    'STAT': '>llllllll', # status requests

    'DBUG': '>l'         # debugging queries

}

resphdrsizes = dict((k, struct.calcsize(v))

                    for k, v in resphdrfmts.iteritems())

def recvcs(sock):

    cs = cStringIO.StringIO()

    s = True

    try:

        while s:

            s = sock.recv(65536)

            cs.write(s)

    finally:

        sock.shutdown(socket.SHUT_RD)

    cs.seek(0)

    return cs