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1 # -*- coding: utf-8 -*- |
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2 |
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3 # Copyright (c) 2004 - 2009 Detlev Offenbach <detlev@die-offenbachs.de> |
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4 # |
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5 |
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6 """ |
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7 Module implementing the single application server and client. |
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8 """ |
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9 |
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10 from PyQt4.QtCore import SIGNAL |
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11 from PyQt4.QtNetwork import QLocalServer, QLocalSocket |
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12 |
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13 import Utilities |
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14 |
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15 class SingleApplicationServer(QLocalServer): |
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16 """ |
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17 Class implementing the single application server base class. |
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18 """ |
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19 def __init__(self, name): |
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20 """ |
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21 Constructor |
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22 |
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23 @param name name this server is listening to (string) |
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24 """ |
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25 QLocalServer.__init__(self) |
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26 |
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27 res = self.listen(name) |
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28 if not res: |
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29 # maybe it crashed last time |
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30 self.removeServer(name) |
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31 self.listen(name) |
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32 |
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33 self.connect(self, SIGNAL("newConnection()"), self.__newConnection) |
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34 |
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35 self.qsock = None |
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36 |
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37 def __newConnection(self): |
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38 """ |
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39 Private slot to handle a new connection. |
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40 """ |
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41 sock = self.nextPendingConnection() |
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42 |
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43 # If we already have a connection, refuse this one. It will be closed |
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44 # automatically. |
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45 if self.qsock is not None: |
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46 return |
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47 |
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48 self.qsock = sock |
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49 |
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50 self.connect(self.qsock, SIGNAL('readyRead()'), self.__parseLine) |
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51 self.connect(self.qsock, SIGNAL('disconnected()'), self.__disconnected) |
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52 |
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53 def __parseLine(self): |
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54 """ |
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55 Private method to handle data from the client. |
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56 """ |
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57 while self.qsock and self.qsock.canReadLine(): |
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58 line = unicode(self.qsock.readLine()) |
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59 |
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60 ## print line ##debug |
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61 |
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62 eoc = line.find('<') + 1 |
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63 |
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64 boc = line.find('>') |
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65 if boc >= 0 and eoc > boc: |
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66 # handle the command sent by the client. |
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67 cmd = line[boc:eoc] |
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68 params = line[eoc:-1] |
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69 |
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70 self.handleCommand(cmd, params) |
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71 |
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72 def __disconnected(self): |
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73 """ |
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74 Private method to handle the closure of the socket. |
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75 """ |
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76 self.qsock = None |
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77 |
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78 def shutdown(self): |
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79 """ |
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80 Public method used to shut down the server. |
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81 """ |
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82 if self.qsock is not None: |
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83 self.disconnect(self.qsock, SIGNAL('readyRead()'), self.__parseLine) |
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84 self.disconnect(self.qsock, SIGNAL('disconnected()'), self.__disconnected) |
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85 |
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86 self.qsock = None |
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87 |
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88 self.close() |
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89 |
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90 def handleCommand(self, cmd, params): |
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91 """ |
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92 Public slot to handle the command sent by the client. |
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93 |
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94 <b>Note</b>: This method must be overridden by subclasses. |
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95 |
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96 @param cmd commandstring (string) |
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97 @param params parameterstring (string) |
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98 """ |
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99 raise RuntimeError("'handleCommand' must be overridden") |
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100 |
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101 class SingleApplicationClient(object): |
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102 """ |
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103 Class implementing the single application client base class. |
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104 """ |
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105 def __init__(self, name): |
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106 """ |
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107 Constructor |
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108 |
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109 @param name name of the local server to connect to (string) |
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110 """ |
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111 self.name = name |
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112 self.connected = False |
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113 |
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114 def connect(self): |
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115 """ |
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116 Public method to connect the single application client to its server. |
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117 |
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118 @return value indicating success or an error number. Value is one of: |
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119 <table> |
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120 <tr><td>0</td><td>No application is running</td></tr> |
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121 <tr><td>1</td><td>Application is already running</td></tr> |
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122 </table> |
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123 """ |
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124 self.sock = QLocalSocket() |
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125 self.sock.connectToServer(self.name) |
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126 if self.sock.waitForConnected(10000): |
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127 self.connected = True |
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128 return 1 |
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129 else: |
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130 err = self.sock.error() |
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131 if err == QLocalSocket.ServerNotFoundError: |
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132 return 0 |
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133 else: |
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134 return -err |
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135 |
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136 def disconnect(self): |
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137 """ |
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138 Public method to disconnect from the Single Appliocation server. |
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139 """ |
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140 self.sock.disconnectFromServer() |
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141 self.connected = False |
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142 |
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143 def processArgs(self, args): |
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144 """ |
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145 Public method to process the command line args passed to the UI. |
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146 |
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147 <b>Note</b>: This method must be overridden by subclasses. |
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148 |
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149 @param args command line args (list of strings) |
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150 """ |
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151 raise RuntimeError("'processArgs' must be overridden") |
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152 |
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153 def sendCommand(self, cmd): |
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154 """ |
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155 Public method to send the command to the application server. |
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156 |
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157 @param cmd command to be sent (string) |
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158 """ |
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159 if self.connected: |
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160 self.sock.write(cmd) |
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161 self.sock.flush() |
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162 |
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163 def errstr(self): |
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164 """ |
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165 Public method to return a meaningful error string for the last error. |
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166 |
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167 @return error string for the last error (string) |
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168 """ |
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169 return self.sock.errorString() |