1 # server.py - inotify common protocol code

     2 #

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

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

     5 #

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

     7 # GNU General Public License version 2 or any later version.

     8 

     9 import cStringIO, socket, struct

    10 

    11 """

    12   Protocol between inotify clients and server:

    13 

    14   Client sending query:

    15   1) send protocol version number

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

    17   3) send query parameters:

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

    19         1) N different names that need checking

    20         2) 1 string containing all the status types to match

    21      - No parameter needed for DBUG

    22 

    23   Server sending query answer:

    24   1) send protocol version number

    25   2) send query type

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

    27       e.g. for STAT, receive 9 integers describing the length of the

    28       9 \0-separated string lists to be read:

    29        * one file list for each lmar!?ic status type

    30        * one list containing the directories visited during lookup

    31 

    32 """

    33 

    34 version = 3

    35 

    36 resphdrfmts = {

    37     'STAT': '>lllllllll', # status requests

    38     'DBUG': '>l'          # debugging queries

    39 }

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

    41                     for k, v in resphdrfmts.iteritems())

    42 

    43 def recvcs(sock):

    44     cs = cStringIO.StringIO()

    45     s = True

    46     try:

    47         while s:

    48             s = sock.recv(65536)

    49             cs.write(s)

    50     finally:

    51         sock.shutdown(socket.SHUT_RD)

    52     cs.seek(0)

    53     return cs