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1 # -*- coding: utf-8 -*- |
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2 |
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3 # Copyright (c) 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 an asynchronous file like socket interface for the debugger. |
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8 """ |
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9 |
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10 import socket |
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11 import sys |
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12 |
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13 from DebugProtocol import EOT, RequestOK |
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14 |
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15 |
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16 def AsyncPendingWrite(file): |
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17 """ |
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18 Module function to check for data to be written. |
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19 |
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20 @param file The file object to be checked (file) |
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21 @return Flag indicating if there is data wating (int) |
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22 """ |
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23 try: |
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24 pending = file.pendingWrite() |
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25 except: |
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26 pending = 0 |
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27 |
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28 return pending |
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29 |
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30 |
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31 class AsyncFile(object): |
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32 """ |
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33 Class wrapping a socket object with a file interface. |
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34 """ |
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35 maxtries = 10 |
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36 maxbuffersize = 1024 * 1024 * 4 |
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37 |
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38 def __init__(self, sock, mode, name): |
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39 """ |
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40 Constructor |
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41 |
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42 @param sock the socket object being wrapped |
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43 @param mode mode of this file (string) |
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44 @param name name of this file (string) |
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45 """ |
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46 # Initialise the attributes. |
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47 self.__closed = False |
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48 self.sock = sock |
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49 self.mode = mode |
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50 self.name = name |
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51 self.nWriteErrors = 0 |
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52 |
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53 self.wpending = '' |
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54 |
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55 def __checkMode(self, mode): |
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56 """ |
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57 Private method to check the mode. |
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58 |
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59 This method checks, if an operation is permitted according to |
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60 the mode of the file. If it is not, an IOError is raised. |
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61 |
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62 @param mode the mode to be checked (string) |
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63 """ |
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64 if mode != self.mode: |
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65 raise IOError((9, '[Errno 9] Bad file descriptor')) |
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66 |
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67 def __nWrite(self, n): |
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68 """ |
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69 Private method to write a specific number of pending bytes. |
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70 |
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71 @param n the number of bytes to be written (int) |
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72 """ |
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73 if n: |
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74 try : |
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75 buf = "{0!s}{1!s}".format(self.wpending[:n], EOT) |
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76 try: |
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77 buf = buf.encode('utf8', 'backslashreplace') |
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78 except (UnicodeEncodeError, UnicodeDecodeError): |
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79 pass |
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80 self.sock.sendall(buf) |
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81 self.wpending = self.wpending[n:] |
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82 self.nWriteErrors = 0 |
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83 except socket.error: |
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84 self.nWriteErrors += 1 |
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85 if self.nWriteErrors > self.maxtries: |
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86 self.wpending = '' # delete all output |
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87 |
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88 def pendingWrite(self): |
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89 """ |
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90 Public method that returns the number of bytes waiting to be written. |
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91 |
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92 @return the number of bytes to be written (int) |
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93 """ |
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94 return self.wpending.rfind('\n') + 1 |
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95 |
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96 def close(self, closeit = False): |
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97 """ |
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98 Public method to close the file. |
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99 |
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100 @param closeit flag to indicate a close ordered by the debugger code (boolean) |
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101 """ |
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102 if closeit and not self.__closed: |
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103 self.flush() |
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104 self.sock.close() |
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105 self.__closed = True |
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106 |
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107 def flush(self): |
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108 """ |
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109 Public method to write all pending bytes. |
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110 """ |
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111 self.__nWrite(len(self.wpending)) |
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112 |
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113 def isatty(self): |
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114 """ |
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115 Public method to indicate whether a tty interface is supported. |
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116 |
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117 @return always false |
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118 """ |
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119 return False |
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120 |
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121 def fileno(self): |
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122 """ |
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123 Public method returning the file number. |
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124 |
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125 @return file number (int) |
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126 """ |
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127 return self.sock.fileno() |
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128 |
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129 def read_p(self, size = -1): |
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130 """ |
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131 Public method to read bytes from this file. |
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132 |
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133 @param size maximum number of bytes to be read (int) |
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134 @return the bytes read (any) |
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135 """ |
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136 self.__checkMode('r') |
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137 |
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138 if size < 0: |
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139 size = 20000 |
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140 |
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141 return self.sock.recv(size).decode('utf8') |
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142 |
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143 def read(self, size = -1): |
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144 """ |
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145 Public method to read bytes from this file. |
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146 |
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147 @param size maximum number of bytes to be read (int) |
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148 @return the bytes read (any) |
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149 """ |
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150 self.__checkMode('r') |
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151 |
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152 buf = input() |
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153 if size >= 0: |
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154 buf = buf[:size] |
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155 return buf |
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156 |
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157 def readline_p(self, size = -1): |
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158 """ |
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159 Public method to read a line from this file. |
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160 |
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161 <b>Note</b>: This method will not block and may return |
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162 only a part of a line if that is all that is available. |
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163 |
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164 @param size maximum number of bytes to be read (int) |
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165 @return one line of text up to size bytes (string) |
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166 """ |
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167 self.__checkMode('r') |
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168 |
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169 if size < 0: |
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170 size = 20000 |
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171 |
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172 # The integration of the debugger client event loop and the connection |
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173 # to the debugger relies on the two lines of the debugger command being |
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174 # delivered as two separate events. Therefore we make sure we only |
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175 # read a line at a time. |
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176 line = self.sock.recv(size, socket.MSG_PEEK) |
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177 |
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178 eol = line.find(b'\n') |
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179 |
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180 if eol >= 0: |
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181 size = eol + 1 |
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182 else: |
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183 size = len(line) |
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184 |
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185 # Now we know how big the line is, read it for real. |
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186 return self.sock.recv(size).decode('utf8') |
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187 |
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188 def readlines(self, sizehint = -1): |
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189 """ |
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190 Public method to read all lines from this file. |
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191 |
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192 @param sizehint hint of the numbers of bytes to be read (int) |
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193 @return list of lines read (list of strings) |
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194 """ |
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195 self.__checkMode('r') |
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196 |
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197 lines = [] |
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198 room = sizehint |
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199 |
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200 line = self.readline_p(room) |
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201 linelen = len(line) |
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202 |
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203 while linelen > 0: |
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204 lines.append(line) |
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205 |
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206 if sizehint >= 0: |
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207 room = room - linelen |
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208 |
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209 if room <= 0: |
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210 break |
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211 |
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212 line = self.readline_p(room) |
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213 linelen = len(line) |
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214 |
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215 return lines |
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216 |
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217 def readline(self, sizehint = -1): |
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218 """ |
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219 Public method to read one line from this file. |
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220 |
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221 @param sizehint hint of the numbers of bytes to be read (int) |
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222 @return one line read (string) |
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223 """ |
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224 self.__checkMode('r') |
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225 |
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226 line = input() + '\n' |
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227 if sizehint >= 0: |
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228 line = line[:sizehint] |
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229 return line |
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230 |
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231 def seek(self, offset, whence = 0): |
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232 """ |
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233 Public method to move the filepointer. |
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234 |
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235 @param offset offset to move the filepointer to (integer) |
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236 @param whence position the offset relates to |
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237 @exception IOError This method is not supported and always raises an |
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238 IOError. |
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239 """ |
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240 raise IOError((29, '[Errno 29] Illegal seek')) |
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241 |
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242 def tell(self): |
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243 """ |
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244 Public method to get the filepointer position. |
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245 |
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246 @exception IOError This method is not supported and always raises an |
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247 IOError. |
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248 """ |
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249 raise IOError((29, '[Errno 29] Illegal seek')) |
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250 |
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251 def truncate(self, size = -1): |
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252 """ |
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253 Public method to truncate the file. |
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254 |
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255 @param size size to truncaze to (integer) |
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256 @exception IOError This method is not supported and always raises an |
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257 IOError. |
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258 """ |
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259 raise IOError((29, '[Errno 29] Illegal seek')) |
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260 |
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261 def write(self, s): |
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262 """ |
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263 Public method to write a string to the file. |
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264 |
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265 @param s bytes to be written (string) |
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266 """ |
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267 self.__checkMode('w') |
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268 tries = 0 |
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269 if not self.wpending: |
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270 self.wpending = s |
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271 elif len(self.wpending) + len(s) > self.maxbuffersize: |
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272 # flush wpending so that different string types are not concatenated |
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273 while self.wpending: |
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274 # if we have a persistent error in sending the data, an exception |
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275 # will be raised in __nWrite |
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276 self.flush() |
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277 tries += 1 |
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278 if tries > self.maxtries: |
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279 raise socket.error("Too many attempts to send data") |
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280 self.wpending = s |
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281 else: |
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282 self.wpending += s |
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283 self.__nWrite(self.pendingWrite()) |
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284 |
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285 def writelines(self, list): |
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286 """ |
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287 Public method to write a list of strings to the file. |
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288 |
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289 @param list the list to be written (list of string) |
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290 """ |
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291 for l in list: |
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292 self.write(l) |