command_executer.py

   1 # Pyvconv - A simple frontend for ffmpeg/mencoder
   2 # Copyright (C) 2008,  Kristian Rumberg (kristianrumberg@gmail.com)
   3
   4 # Permission to use, copy, modify, and/or distribute this software for any
   5 # purpose with or without fee is hereby granted, provided that the above
   6 # copyright notice and this permission notice appear in all copies.
   7
   8 # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15
  16 import os
  17 import time
  18 import datetime
  19 import subprocess
  20 import thread
  21 import threading
  22 import signal
  23 from commands import Variable
  24
  25 class CommandExecuterView:
  26     def __init__(self):
  27         pass
  28
  29     def recieve_executor(self, executor):
  30         pass
  31
  32     def starting_conversion(self, infile, index, total, outfile):
  33         pass
  34
  35     def update_progress(self, logline):
  36         pass
  37
  38     def error(self):
  39         pass
  40
  41     def finished_all(self):
  42         pass
  43
  44 class CommandExecuter:
  45     def mk_unique_subdir(self, parentdir):
  46         t = datetime.datetime.now()
  47         newdir = parentdir + "/" + self.command.get_name().replace("/", "_") + "_" + str(time.mktime(t.timetuple()))
  48
  49         if os.path.isdir(newdir):
  50             raise OSError("Unable to make up unique name for new folder")
  51         elif os.path.isfile(newdir):
  52             raise OSError("a file with the same name as the desired " \
  53                       "dir, '%s', already exists." % newdir)
  54         else:
  55             os.mkdir(newdir)
  56             return newdir
  57
  58     def __init__(self, cmdexecview, command, infilelist, outdir):
  59         self.cmdexecview = cmdexecview
  60         self.command = command
  61         self.infilelist = infilelist
  62         self.outdir = self.mk_unique_subdir(outdir)
  63
  64         self.please_abort = False
  65
  66         self.shared_vars_lock = threading.Lock()
  67         thread.start_new_thread(self._run_conversion, ())
  68
  69     def abort(self):
  70         self.shared_vars_lock.acquire()
  71         self.please_abort = True
  72         self.shared_vars_lock.release()
  73
  74     def _run_conversion(self):
  75         index = 0
  76         total = len(self.infilelist)
  77
  78         for infile in self.infilelist:
  79             outfile = self.outdir + "/" + os.path.basename(infile) + "_converted"
  80
  81             index = index + 1
  82
  83             self.command.put_var(Variable("in", infile))
  84             self.command.put_var(Variable("out", outfile))
  85
  86             self.cmdexecview.starting_conversion(infile, index, total, outfile)
  87
  88             p = subprocess.Popen(str(self.command), shell = True, universal_newlines=True, stderr = subprocess.PIPE)
  89             ostream = p.stderr
  90
  91             self.cmdexecview.recieve_executor(self)
  92
  93             newline = str(chr(32) * 4)
  94             buff = ""
  95             c = 1
  96             iskip = 10
  97             skipc = 0
  98
  99             while c:
 100                 c = ostream.read(1)
 101                 buff = buff + c
 102                 if buff.endswith(newline):
 103                     skipc = (skipc + 1) % iskip
 104                     if skipc == 0:
 105                         self.cmdexecview.update_progress(buff.strip())
 106                     buff = ""
 107
 108                 self.shared_vars_lock.acquire()
 109                 if self.please_abort == True:
 110                     ostream.close()
 111                     os.kill(p.pid, signal.SIGTERM)
 112                     return
 113                 self.shared_vars_lock.release()
 114
 115             ostream.close()
 116
 117             res = p.wait()
 118
 119             if res < 0:
 120                 self.cmdexecview.error()
 121                 return
 122
 123         self.cmdexecview.finished_all()