~azzar1/unity/add-show-desktop-key

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
# IVLE - Informatics Virtual Learning Environment
# Copyright (C) 2007-2008 The University of Melbourne
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

# Module: Chat
# Author: Thomas Conway
# Date:   5/2/2008

import cjson
import cStringIO
import md5
import sys
import os
import socket
import traceback

class Terminate(Exception):
    """Exception thrown when server is to be shut down. It will attempt to sned 
    the final_response to the client and then exits"""
    def __init__(self, final_response=None):
        self.final_response = final_response

    def __str__(self):
        return repr(self.final_response)


def start_server(port, magic, daemon_mode, handler, initializer = None):
    # Attempt to open the socket.
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.bind(('', port))
    s.listen(1)

    # Excellent! It worked. Let's turn ourself into a daemon,
    # then get on with the job of being a python interpreter.
    if daemon_mode:
        if os.fork():   # launch child and...
            os._exit(0) # kill off parent
        os.setsid()
        if os.fork():   # launch child and...
            os._exit(0) # kill off parent again.
        os.umask(077)

        try:
            MAXFD = os.sysconf("SC_OPEN_MAX")
        except:
            MAXFD = 256

        # Close all file descriptors, except the socket.
        for i in xrange(MAXFD):
            if i == s.fileno():
                continue
            try:
                os.close(i)
            except OSError:
                pass

        si = os.open(os.devnull, os.O_RDONLY)
        os.dup2(si, sys.stdin.fileno())

        so = os.open(os.devnull, os.O_WRONLY)
        os.dup2(so, sys.stdout.fileno())

        se = os.open(os.devnull, os.O_WRONLY)
        os.dup2(se, sys.stderr.fileno())

    if initializer:
        initializer()

    while True:
        (conn, addr) = s.accept()
        try:
            # Grab the input
            buf = cStringIO.StringIO()
            blk = conn.recv(1024)
            while blk:
                buf.write(blk)
                try:
                    blk = conn.recv(1024, socket.MSG_DONTWAIT)
                except:
                    # Exception thrown if it WOULD block (but we
                    # told it not to wait) - ie. we are done
                    blk = None
            inp = buf.getvalue()
            env = cjson.decode(inp)
            
            # Check that the message is 
            digest = md5.new(env['content'] + magic).digest().encode('hex')
            if env['digest'] != digest:
                conn.close()
                continue

            content = cjson.decode(env['content'])

            response = handler(content)

            conn.sendall(cjson.encode(response))

            conn.close()

        except Terminate, t:
            # Try and send final response and then terminate
            if t.final_response:
                conn.sendall(cjson.encode(t.final_response))
            conn.close()
            sys.exit(0)
        except Exception:
            # Make a JSON object full of exceptional goodness
            tb_dump = cStringIO.StringIO()
            e_type, e_val, e_tb = sys.exc_info()
            traceback.print_tb(e_tb, file=tb_dump)
            json_exc = {
                "type": e_type.__name__,
                "value": str(e_val),
                "traceback": tb_dump.getvalue()
            }
            conn.sendall(cjson.encode(json_exc))
            conn.close()


def chat(host, port, msg, magic, decode = True):
    sok = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sok.connect((host, port))
    content = cjson.encode(msg)
    digest = md5.new(content + magic).digest().encode("hex")
    env = {'digest':digest,'content':content}
    sok.send(cjson.encode(env))

    buf = cStringIO.StringIO()
    blk = sok.recv(1024)
    while blk:
        buf.write(blk)
        try:
            blk = sok.recv(1024, socket.MSG_DONTWAIT)
        except socket.error, e:
            if e[0] != 11:
                raise
            # Exception thrown if it WOULD block (but we
            # told it not to wait) - ie. we are done
            blk = None
    inp = buf.getvalue()
    sok.close()

    if decode:
        return cjson.decode(inp)
    else:
        return inp