[564] | 1 | # -*- coding: UTF-8 -*- |
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[217] | 2 | # |
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| 3 | # pkpgcounter : a generic Page Description Language parser |
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| 4 | # |
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[564] | 5 | # (c) 2003, 2004, 2005, 2006, 2007, 2008 Jerome Alet <alet@librelogiciel.com> |
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[463] | 6 | # This program is free software: you can redistribute it and/or modify |
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[217] | 7 | # it under the terms of the GNU General Public License as published by |
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[463] | 8 | # the Free Software Foundation, either version 3 of the License, or |
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[217] | 9 | # (at your option) any later version. |
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[463] | 10 | # |
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[217] | 11 | # This program is distributed in the hope that it will be useful, |
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| 12 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 14 | # GNU General Public License for more details. |
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| 15 | # |
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| 16 | # You should have received a copy of the GNU General Public License |
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[463] | 17 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
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[217] | 18 | # |
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| 19 | # $Id$ |
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| 20 | # |
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| 21 | |
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[354] | 22 | """This modules implements a page counter for TIFF documents.""" |
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| 23 | |
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[217] | 24 | import sys |
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| 25 | import os |
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| 26 | import mmap |
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| 27 | from struct import unpack |
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| 28 | |
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[235] | 29 | import pdlparser |
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[217] | 30 | |
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[220] | 31 | class Parser(pdlparser.PDLParser) : |
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[217] | 32 | """A parser for TIFF documents.""" |
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[527] | 33 | totiffcommands = [ 'cp "%(infname)s" "%(outfname)s"' ] |
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| 34 | required = [ "cp" ] |
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[555] | 35 | format = "TIFF" |
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[220] | 36 | def isValid(self) : |
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[387] | 37 | """Returns True if data is TIFF, else False.""" |
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[220] | 38 | littleendian = (chr(0x49)*2) + chr(0x2a) + chr(0) |
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| 39 | bigendian = (chr(0x4d)*2) + chr(0) + chr(0x2a) |
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[522] | 40 | if self.firstblock[:4] in (littleendian, bigendian) : |
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[387] | 41 | return True |
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[220] | 42 | else : |
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[387] | 43 | return False |
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[220] | 44 | |
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[217] | 45 | def getJobSize(self) : |
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| 46 | """Counts pages in a TIFF document. |
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[219] | 47 | |
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| 48 | Algorithm by Jerome Alet. |
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| 49 | |
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| 50 | The documentation used for this was : |
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| 51 | |
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| 52 | http://www.ee.cooper.edu/courses/course_pages/past_courses/EE458/TIFF/ |
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[217] | 53 | """ |
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| 54 | infileno = self.infile.fileno() |
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| 55 | minfile = mmap.mmap(infileno, os.fstat(infileno)[6], prot=mmap.PROT_READ, flags=mmap.MAP_SHARED) |
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| 56 | pagecount = 0 |
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| 57 | littleendian = (chr(0x49)*2) + chr(0x2a) + chr(0) |
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| 58 | bigendian = (chr(0x4d)*2) + chr(0) + chr(0x2a) |
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| 59 | if minfile[:4] == littleendian : |
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| 60 | integerbyteorder = "<I" |
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| 61 | shortbyteorder = "<H" |
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[354] | 62 | elif minfile[:4] == bigendian : |
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[217] | 63 | integerbyteorder = ">I" |
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| 64 | shortbyteorder = ">H" |
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[354] | 65 | else : |
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| 66 | raise pdlparser.PDLParserError, "Unknown file endianness." |
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[217] | 67 | pos = 4 |
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[489] | 68 | try : |
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| 69 | try : |
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[219] | 70 | nextifdoffset = unpack(integerbyteorder, minfile[pos : pos + 4])[0] |
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[489] | 71 | while nextifdoffset : |
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| 72 | direntrycount = unpack(shortbyteorder, minfile[nextifdoffset : nextifdoffset + 2])[0] |
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| 73 | pos = nextifdoffset + 2 + (direntrycount * 12) |
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| 74 | nextifdoffset = unpack(integerbyteorder, minfile[pos : pos + 4])[0] |
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| 75 | pagecount += 1 |
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| 76 | except IndexError : |
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| 77 | pass |
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| 78 | finally : |
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| 79 | minfile.close() |
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[217] | 80 | return pagecount |
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