| 1 | # Officeshots.org - Test your office documents in different applications |
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| 2 | # Copyright (C) 2009 Stichting Lone Wolves |
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| 3 | # Written by Sander Marechal <s.marechal@jejik.com> |
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| 4 | # |
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| 5 | # This program is free software: you can redistribute it and/or modify |
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| 6 | # it under the terms of the GNU Affero General Public License as |
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| 7 | # published by the Free Software Foundation, either version 3 of the |
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| 8 | # License, or (at your option) any later version. |
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| 9 | # |
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| 10 | # This program is distributed in the hope that it will be useful, |
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| 11 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 13 | # GNU Affero General Public License for more details. |
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| 14 | # |
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| 15 | # You should have received a copy of the GNU Affero General Public License |
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| 16 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
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| 17 | |
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| 18 | """ |
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| 19 | The core backend class |
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| 20 | """ |
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| 21 | |
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| 22 | import os |
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| 23 | import base64 |
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| 24 | import logging |
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| 25 | |
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| 26 | class BackendException: |
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| 27 | """ |
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| 28 | A base Backend exception class. Backends should derive their own |
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| 29 | exceptions from this. |
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| 30 | |
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| 31 | When the Factory catches this exception and recoverable is False, then |
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| 32 | the backend will be unloaded. |
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| 33 | """ |
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| 34 | def __init__(self, message, recoverable = False): |
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| 35 | self.message = message |
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| 36 | self.recoverable = recoverable |
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| 37 | |
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| 38 | def __str__(self): |
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| 39 | if self.recoverable: |
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| 40 | return self.message + ' (Recoverable)' |
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| 41 | return self.message + ' (Not recoverable)' |
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| 42 | |
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| 43 | class Backend: |
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| 44 | """ |
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| 45 | The base backend class. Backends shoudl derive from this |
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| 46 | """ |
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| 47 | def __init__(self, options, config, section): |
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| 48 | self.options = options |
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| 49 | self.config = config |
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| 50 | self.section = section |
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| 51 | |
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| 52 | self.application = config.get(section, 'application').lower() |
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| 53 | self.version = config.get(section, 'version').lower() |
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| 54 | self.doctype = [s.strip() for s in config.get(section, 'doctype').split(',')] |
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| 55 | self.formats = [s.strip() for s in config.get(section, 'formats').split(',')] |
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| 56 | |
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| 57 | def initialize(self): |
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| 58 | """ |
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| 59 | This is called right after instanciating the backend. |
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| 60 | """ |
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| 61 | pass |
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| 62 | |
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| 63 | def can_process(self, job): |
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| 64 | """ |
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| 65 | Return True if this backend is eligable to process this Job, False otherwise |
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| 66 | """ |
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| 67 | eligable = ( |
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| 68 | job['application'].lower() == self.application and |
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| 69 | job['version'].lower() == self.version and |
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| 70 | job['doctype'] in self.doctype and |
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| 71 | (job['format'] == '' or job['format'] in self.formats) |
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| 72 | ) |
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| 73 | |
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| 74 | return eligable |
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| 75 | |
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| 76 | def process(self, job): |
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| 77 | """ |
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| 78 | Process a job. Backends must override this method. |
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| 79 | """ |
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| 80 | raise NotImplementedError |
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| 81 | |
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| 82 | def save_document(self, job): |
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| 83 | """ |
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| 84 | Save the file in a job to a temporary location and return the full path. |
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| 85 | Note that the job ID is used to form the name rather than the original filename |
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| 86 | to help avoid collisions. |
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| 87 | """ |
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| 88 | if not 'job' in job or not 'filename' in job or not 'doctype' in job or not 'document' in job: |
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| 89 | raise BackendException('Could not save job document to temporary file. Invalid job.', True) |
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| 90 | |
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| 91 | (root, ext) = os.path.splitext(job['filename']) |
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| 92 | tmp_dir = os.path.normpath(self.config.get('global', 'tmp_files')) |
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| 93 | if not os.path.exists(tmp_dir): |
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| 94 | logging.info('Temporary storage %s does not exist. Attempting to create', tmp_dir) |
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| 95 | try: |
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| 96 | os.makedirs(tmp_dir) |
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| 97 | except OSError: |
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| 98 | raise BackendException('Could not create temporary storage location %s' % tmp_dir) |
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| 99 | |
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| 100 | filename = os.path.join(tmp_dir, job['job'] + ext) |
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| 101 | logging.debug('Temporary filename: %s' % filename) |
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| 102 | try: |
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| 103 | file = open(filename, 'wb') |
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| 104 | file.write(base64.b64decode(job['document'])) |
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| 105 | file.close() |
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| 106 | except IOError, e: |
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| 107 | raise BackendException('Could not write temporary file %s (%s)' % (filename, e)) |
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| 108 | except TypeError, e: |
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| 109 | raise BackendException('Document is not base64 encoded (%s)' % e, True) |
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| 110 | |
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| 111 | return filename |
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| 112 | |
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| 113 | def load_document(self, path, encode=True): |
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| 114 | try: |
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| 115 | file = open(path, 'rb') |
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| 116 | contents = file.read() |
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| 117 | file.close() |
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| 118 | except (IOError): |
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| 119 | raise BackendException('Could not read file %s' % path, True) |
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| 120 | |
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| 121 | if contents == '': |
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| 122 | raise BackendException('File %s is empty' % path, True) |
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| 123 | |
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| 124 | if encode: |
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| 125 | contents = base64.b64encode(contents) |
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| 126 | return contents |
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| 127 | |
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