paramiko.pipe

- 1 # Copyright (C) 2003-2007 Robey Pointer <robeypointer@gmail.com> - 2 # - 3 # This file is part of paramiko. - 4 # - 5 # Paramiko is free software; you can redistribute it and/or modify it under the - 6 # terms of the GNU Lesser General Public License as published by the Free - 7 # Software Foundation; either version 2.1 of the License, or (at your option) - 8 # any later version. - 9 # - 10 # Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY - 11 # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR - 12 # A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more - 13 # details. - 14 # - 15 # You should have received a copy of the GNU Lesser General Public License - 16 # along with Paramiko; if not, write to the Free Software Foundation, Inc., - 17 # 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. - 18 - 19 """ - 20 Abstraction of a one-way pipe where the read end can be used in select(). - 21 Normally this is trivial, but Windows makes it nearly impossible. - 22 - 23 The pipe acts like an Event, which can be set or cleared. When set, the pipe - 24 will trigger as readable in select(). - 25 """ - 26 - 27 import sys - 28 import os - 29 import socket - 30 - 31 -

32 -def make_pipe (): -

33 if sys.platform[:3] != 'win': - 34 p = PosixPipe() - 35 else: - 36 p = WindowsPipe() - 37 return p -

38 - 39 -

40 -class PosixPipe (object): -

41 - def __init__ (self): -

42 self._rfd, self._wfd = os.pipe() - 43 self._set = False - 44 self._forever = False - 45 self._closed = False -

46 -

47 - def close (self): -

48 os.close(self._rfd) - 49 os.close(self._wfd) - 50 # used for unit tests: - 51 self._closed = True -

52 -

53 - def fileno (self): -

54 return self._rfd -

55 -

56 - def clear (self): -

57 if not self._set or self._forever: - 58 return - 59 os.read(self._rfd, 1) - 60 self._set = False -

61 -

62 - def set (self): -

63 if self._set or self._closed: - 64 return - 65 self._set = True - 66 os.write(self._wfd, '*') -

67 -

68 - def set_forever (self): -

69 self._forever = True - 70 self.set() -

71 - 72 -

73 -class WindowsPipe (object): -

74 """ - 75 On Windows, only an OS-level "WinSock" may be used in select(), but reads - 76 and writes must be to the actual socket object. - 77 """ -

78 - def __init__ (self): -

79 serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM) - 80 serv.bind(('127.0.0.1', 0)) - 81 serv.listen(1) - 82 - 83 # need to save sockets in _rsock/_wsock so they don't get closed - 84 self._rsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) - 85 self._rsock.connect(('127.0.0.1', serv.getsockname()[1])) - 86 - 87 self._wsock, addr = serv.accept() - 88 serv.close() - 89 self._set = False - 90 self._forever = False - 91 self._closed = False -

92 -

93 - def close (self): -

94 self._rsock.close() - 95 self._wsock.close() - 96 # used for unit tests: - 97 self._closed = True -

98 -

99 - def fileno (self): -

100 return self._rsock.fileno() -

101 -

102 - def clear (self): -

103 if not self._set or self._forever: -104 return -105 self._rsock.recv(1) -106 self._set = False -

107 -

108 - def set (self): -

109 if self._set or self._closed: -110 return -111 self._set = True -112 self._wsock.send('*') -

113 -

114 - def set_forever (self): -

115 self._forever = True -116 self.set() -

117 -118 -

119 -class OrPipe (object): -

120 - def __init__(self, pipe): -

121 self._set = False -122 self._partner = None -123 self._pipe = pipe -

124 -

125 - def set(self): -

126 self._set = True -127 if not self._partner._set: -128 self._pipe.set() -

129 -

130 - def clear(self): -

131 self._set = False -132 if not self._partner._set: -133 self._pipe.clear() -

134 -135 -

136 -def make_or_pipe(pipe): -

137 """ -138 wraps a pipe into two pipe-like objects which are "or"d together to -139 affect the real pipe. if either returned pipe is set, the wrapped pipe -140 is set. when both are cleared, the wrapped pipe is cleared. -141 """ -142 p1 = OrPipe(pipe) -143 p2 = OrPipe(pipe) -144 p1._partner = p2 -145 p2._partner = p1 -146 return p1, p2 -

147 -

Source Code for Module paramiko.pipe