misc/wStringIO.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3 #
   4 # Copyright 2004-2006 Zuza Software Foundation
   5 #
   6 # This file is part of translate.
   7 #
   8 # translate is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 2 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # translate is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with translate; if not, write to the Free Software
  20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21
  22 """A wrapper for cStringIO that provides more of the functions of StringIO at the speed of cStringIO"""
  23
  24 import cStringIO
  25
  26 class StringIO:
  27     def __init__(self, buf = ''):
  28         if not isinstance(buf, (str, unicode)):
  29             buf = str(buf)
  30         if isinstance(buf, unicode):
  31             buf = buf.encode('utf-8')
  32         self.len = len(buf)
  33         self.buf = cStringIO.StringIO()
  34         self.buf.write(buf)
  35         self.buf.seek(0)
  36         self.pos = 0
  37         self.closed = 0
  38
  39     def __iter__(self):
  40         return self
  41
  42     def next(self):
  43         if self.closed:
  44             raise StopIteration
  45         r = self.readline()
  46         if not r:
  47             raise StopIteration
  48         return r
  49
  50     def close(self):
  51         """Free the memory buffer.
  52         """
  53         if not self.closed:
  54             self.closed = 1
  55             del self.buf, self.pos
  56
  57     def isatty(self):
  58         if self.closed:
  59             raise ValueError, "I/O operation on closed file"
  60         return False
  61
  62     def seek(self, pos, mode = 0):
  63         if self.closed:
  64             raise ValueError, "I/O operation on closed file"
  65         self.buf.seek(pos, mode)
  66         self.pos = self.buf.tell()
  67
  68     def tell(self):
  69         if self.closed:
  70             raise ValueError, "I/O operation on closed file"
  71         return self.pos
  72
  73     def read(self, n = None):
  74         if self.closed:
  75             raise ValueError, "I/O operation on closed file"
  76         if n == None:
  77             r = self.buf.read()
  78         else:
  79             r = self.buf.read(n)
  80         self.pos = self.buf.tell()
  81         return r
  82
  83     def readline(self, length=None):
  84         if self.closed:
  85             raise ValueError, "I/O operation on closed file"
  86         if length is not None:
  87             r = self.buf.readline(length)
  88         else:
  89             r = self.buf.readline(length)
  90         self.pos = self.buf.tell()
  91         return r
  92
  93     def readlines(self):
  94         if self.closed:
  95             raise ValueError, "I/O operation on closed file"
  96         lines = self.buf.readlines()
  97         self.pos = self.buf.tell()
  98         return lines
  99
 100     def truncate(self, size=None):
 101         if self.closed:
 102             raise ValueError, "I/O operation on closed file"
 103         self.buf.truncate(size)
 104         self.pos = self.buf.tell()
 105         self.buf.seek(0, 2)
 106         self.len = self.buf.tell()
 107         self.buf.seek(self.pos)
 108
 109     def write(self, s):
 110         if self.closed:
 111             raise ValueError, "I/O operation on closed file"
 112         origpos = self.buf.tell()
 113         self.buf.write(s)
 114         self.pos = self.buf.tell()
 115         if origpos + len(s) > self.len:
 116             self.buf.seek(0, 2)
 117             self.len = self.buf.tell()
 118             self.buf.seek(self.pos)
 119
 120     def writelines(self, lines):
 121         if self.closed:
 122             raise ValueError, "I/O operation on closed file"
 123         self.buf.writelines(lines)
 124         self.pos = self.buf.tell()
 125         self.buf.seek(0, 2)
 126         self.len = self.buf.tell()
 127         self.buf.seek(self.pos)
 128
 129     def flush(self):
 130         if self.closed:
 131             raise ValueError, "I/O operation on closed file"
 132         self.buf.flush()
 133
 134     def getvalue(self):
 135         if self.closed:
 136             raise ValueError, "I/O operation on closed file"
 137         return self.buf.getvalue()
 138
 139 class CatchStringOutput(StringIO, object):
 140     """catches the output before it is closed and sends it to an onclose method"""
 141     def __init__(self, onclose):
 142         """Set up the output stream, and remember a method to call on closing"""
 143         StringIO.__init__(self)
 144         self.onclose = onclose
 145
 146     def close(self):
 147         """wrap the underlying close method, to pass the value to onclose before it goes"""
 148         value = self.getvalue()
 149         self.onclose(value)
 150         super(CatchStringOutput, self).close()
 151
 152     def slam(self):
 153         """use this method to force the closing of the stream if it isn't closed yet"""
 154         if not self.closed:
 155             self.close()
 156