1 | # -*- coding: utf-8 -*- |
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2 | # |
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3 | # pkpgcounter : a generic Page Description Language parser |
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4 | # |
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5 | # (c) 2003-2009 Jerome Alet <alet@librelogiciel.com> |
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6 | # This program is free software: you can redistribute it and/or modify |
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7 | # it under the terms of the GNU General Public License as published by |
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8 | # the Free Software Foundation, either version 3 of the License, or |
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9 | # (at your option) any later version. |
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10 | # |
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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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17 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
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18 | # |
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19 | # $Id$ |
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20 | # |
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21 | |
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22 | """This modules implements a page counter for Structured Fax documents.""" |
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23 | |
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24 | import struct |
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25 | |
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26 | import pdlparser |
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27 | |
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28 | class Parser(pdlparser.PDLParser) : |
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29 | """A parser for Structured Fax documents.""" |
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30 | format = "Structured Fax" |
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31 | def isValid(self) : |
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32 | """Returns True if data is Structured Fax, else False.""" |
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33 | if self.firstblock.startswith("Sfff") : |
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34 | return True |
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35 | else : |
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36 | return False |
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37 | |
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38 | def getJobSize(self) : |
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39 | """Counts pages in a Structured Fax document. |
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40 | |
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41 | Algorithm by Jerome Alet. |
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42 | |
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43 | The documentation used for this was : |
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44 | |
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45 | http://delphi.pjh2.de/articles/graphic/sff_format.php |
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46 | """ |
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47 | unpack = struct.unpack |
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48 | pagecount = 0 |
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49 | docheader = self.infile.read(20) |
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50 | try : |
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51 | (sffid, |
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52 | version, |
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53 | reserved, |
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54 | userinfo, |
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55 | docpagecount, |
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56 | offsetfirstpage, |
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57 | offsetlastpage, |
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58 | offsetdocumentend) = unpack("<4sBBHHHII", docheader) |
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59 | self.infile.seek(offsetfirstpage - len(docheader), 1) |
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60 | while True : |
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61 | headerid = self.infile.read(1) |
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62 | if not headerid : |
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63 | break |
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64 | headerid = ord(headerid) |
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65 | if 1 <= headerid <= 216 : # Normal record header |
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66 | self.infile.seek(headerid, 1) |
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67 | elif headerid == 255 : # Illegal line / Additional user info |
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68 | additionalbyte = self.infile.read(1) |
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69 | if not additionalbyte : |
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70 | break |
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71 | additionalbyte = ord(additionalbyte) |
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72 | if 1 <= additionalbyte <= 255 : |
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73 | # Skip additional user information (reserved) |
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74 | self.infile.seek(additionalbyte, 1) |
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75 | elif not headerid : |
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76 | # Record with more than 216 MH-coded bytes |
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77 | recordlen = self.infile.read(2) |
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78 | if not recordlen : |
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79 | break |
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80 | recordlen = unpack("<H", recordlen)[0] |
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81 | self.infile.seek(recordlen, 1) |
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82 | elif headerid == 254 : # Page header |
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83 | pageheader = self.infile.read(17) |
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84 | if not pageheader : |
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85 | break |
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86 | headerlen = ord(pageheader[0]) |
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87 | if not headerlen : |
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88 | break # End Of Document |
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89 | (vres, |
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90 | hres, |
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91 | coding, |
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92 | reserved, |
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93 | linelen, |
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94 | pagelen, |
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95 | offsetpreviouspage, |
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96 | offsetnextpage) = unpack("<4BHHII", pageheader[1:]) |
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97 | pagecount += 1 |
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98 | if (offsetnextpage == 1) or (vres == 255) : |
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99 | break # End Of Document |
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100 | self.infile.seek(offsetnextpage, 1) |
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101 | except struct.error : |
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102 | raise pdlparser.PDLParserError, "Invalid Structured Fax datas" |
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103 | return max(docpagecount, pagecount) |
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