root / pkpgcounter / trunk / pkpgpdls / bj.py @ 3488

Revision 3474, 2.3 kB (checked in by jerome, 16 years ago)

Changed copyright years.

  • Property svn:keywords set to Author Id Date Revision
Line 
1# -*- coding: utf-8 -*-
2#
3# pkpgcounter : a generic Page Description Language parser
4#
5# (c) 2003-2009 Jerome Alet <alet@librelogiciel.com>
6# This program is free software: you can redistribute it and/or modify
7# it under the terms of the GNU General Public License as published by
8# the Free Software Foundation, either version 3 of the License, or
9# (at your option) any later version.
10#
11# This program is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14# GNU General Public License for more details.
15#
16# You should have received a copy of the GNU General Public License
17# along with this program.  If not, see <http://www.gnu.org/licenses/>.
18#
19# $Id$
20#
21
22"""This modules implements a page counter for Canon BJ documents."""
23
24import os
25import mmap
26
27import pdlparser
28
29class Parser(pdlparser.PDLParser) :
30    """A parser for Canon BJ documents."""
31    format = "Canon BJ/BJC"
32    def isValid(self) :
33        """Returns True if data is BJ/BJC, else False."""
34        if self.firstblock.startswith("\033[K\002\000") :
35            return True
36        else :
37            return False
38
39    def getJobSize(self) :
40        """Counts pages in a Canon BJ document.
41
42           Algorithm by Jerome Alet.
43
44           The documentation used for this was :
45
46           ghostscript-8.60/src/gdevbj*.c
47        """
48        infileno = self.infile.fileno()
49        minfile = mmap.mmap(infileno, os.fstat(infileno)[6], prot=mmap.PROT_READ, flags=mmap.MAP_SHARED)
50        pagecount = 0
51        pos = 0
52        try :
53            try :
54                while True :
55                    if minfile[pos] == "\033" :
56                        # Look if we've found an initialization sequence
57                        # through the Set Initial Condition command
58                        pageheader = minfile[pos:pos+7]
59                        if pageheader in ("\033[K\002\000\000\017",
60                                          "\033[K\002\000\000\044",
61                                          "\033[K\002\000\004\044") :
62                            pagecount += 1
63                            pos += 6
64                    pos += 1
65            except IndexError : # EOF ?
66                pass
67        finally :
68            minfile.close() # reached EOF
69        return pagecount
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