gsh/dispatchers.py

   1 # This program is free software; you can redistribute it and/or modify
   2 # it under the terms of the GNU General Public License as published by
   3 # the Free Software Foundation; either version 2 of the License, or
   4 # (at your option) any later version.
   5 #
   6 # This program is distributed in the hope that it will be useful,
   7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 # GNU Library General Public License for more details.
  10 #
  11 # You should have received a copy of the GNU General Public License
  12 # along with this program; if not, write to the Free Software
  13 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  14 #
  15 # See the COPYING file for license information.
  16 #
  17 # Copyright (c) 2006, 2007, 2008 Guillaume Chazarain <guichaz@gmail.com>
  18
  19 import asyncore
  20 import fcntl
  21 import struct
  22 import termios
  23
  24 from gsh import remote_dispatcher
  25 from gsh.terminal_size import terminal_size
  26
  27 def all_instances():
  28     """Iterator over all the remote_dispatcher instances"""
  29     for i in asyncore.socket_map.itervalues():
  30         if isinstance(i, remote_dispatcher.remote_dispatcher):
  31             yield i
  32
  33 def make_unique_name(name):
  34     """Each shell must have a unique display name, so identical hostnames are
  35     suffixed by #NUMBER"""
  36     display_names = set([i.display_name for i in all_instances()])
  37     candidate_name = name
  38     i = 0
  39     while candidate_name in display_names:
  40         i += 1
  41         candidate_name = '%s#%d' % (name, i)
  42     return candidate_name
  43
  44 def count_awaited_processes():
  45     """Return a tuple with the number of awaited processes and the total
  46     number"""
  47     awaited = 0
  48     total = 0
  49     for i in all_instances():
  50         if i.enabled:
  51             total += 1
  52             if i.state is not remote_dispatcher.STATE_IDLE:
  53                 awaited += 1
  54     return awaited, total
  55
  56 def all_terminated():
  57     """For each remote shell determine if its terminated"""
  58     instances_found = False
  59     for i in all_instances():
  60         instances_found = True
  61         if i.state not in (remote_dispatcher.STATE_TERMINATED,
  62                            remote_dispatcher.STATE_DEAD):
  63             return False
  64     return instances_found
  65
  66 max_display_name_length = 0
  67 def update_max_display_name_length(change):
  68     """The max_display_name_length serves to compute the length of the
  69     whitespace used to align the output of the remote shells. A positive change
  70     argument indicates that a remote shells with such a name length was enabled
  71     while a negative change argument indicates a disabled remote shell"""
  72     global max_display_name_length
  73
  74     if change < 0:
  75         if -change < max_display_name_length:
  76             # The disabled shell didn't have the longest name
  77             return
  78         new_max = 0
  79         for i in all_instances():
  80             if i.enabled:
  81                 l = len(i.display_name)
  82                 if l >= -change:
  83                     # The disabled shell was not alone with the longest name
  84                     return
  85                 new_max = max(l, new_max)
  86     else:
  87         new_max = max(change, max_display_name_length)
  88
  89     if new_max != max_display_name_length:
  90         max_display_name_length = new_max
  91         update_terminal_size()
  92
  93 def update_terminal_size():
  94     """Propagate the terminal size to the remote shells accounting for the
  95     place taken by the longest name"""
  96     w, h = terminal_size()
  97     w = max(w - max_display_name_length - 2, min(w, 10))
  98     # python bug http://python.org/sf/1112949 on amd64
  99     # from ajaxterm.py
 100     bug = struct.unpack('i', struct.pack('I', termios.TIOCSWINSZ))[0]
 101     packed_size = struct.pack('HHHH', h, w, 0, 0)
 102     term_size = w, h
 103     for i in all_instances():
 104         if i.enabled and i.term_size != term_size:
 105             i.term_size = term_size
 106             fcntl.ioctl(i.fd, bug, packed_size)
 107
 108 def format_info(info_list):
 109     """Turn a 2-dimension list of strings into a 1-dimension list of strings
 110     with correct spacing"""
 111     info_list.sort(key=lambda i:i[0])
 112     max_lengths = []
 113     if info_list:
 114         nr_columns = len(info_list[0])
 115     else:
 116         nr_columns = 0
 117     for i in xrange(nr_columns):
 118         max_lengths.append(max([len(str(info[i])) for info in info_list]))
 119     for info_id in xrange(len(info_list)):
 120         info = info_list[info_id]
 121         for str_id in xrange(len(info)):
 122             orig_str = str(info[str_id])
 123             indent = max_lengths[str_id] - len(orig_str)
 124             info[str_id] = orig_str + indent * ' '
 125         info_list[info_id] = ' '.join(info) + '\n'
 126
 127