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https://github.com/gryf/ebook-converter.git
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gryf
0f9792df36
Here is the first batch of modules, which are needed for converting several formats to LRF. Some of the logic has been change, more cleanups will follow.
92 lines
2.9 KiB
Python
92 lines
2.9 KiB
Python
# -*- coding: utf-8 -*-
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from __future__ import absolute_import, division, print_function, unicode_literals
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'''
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Read the header data from a pdb file.
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'''
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__license__ = 'GPL v3'
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__copyright__ = '2009, John Schember <john@nachtimwald.com>'
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__docformat__ = 'restructuredtext en'
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import re
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import struct
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import time
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from ebook_converter.polyglot.builtins import long_type
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class PdbHeaderReader(object):
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def __init__(self, stream):
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self.stream = stream
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self.ident = self.identity()
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self.num_sections = self.section_count()
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self.title = self.name()
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def identity(self):
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self.stream.seek(60)
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ident = self.stream.read(8)
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return ident.decode('utf-8')
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def section_count(self):
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self.stream.seek(76)
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return struct.unpack('>H', self.stream.read(2))[0]
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def name(self):
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self.stream.seek(0)
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return re.sub(b'[^-A-Za-z0-9 ]+', b'_', self.stream.read(32).replace(b'\x00', b''))
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def full_section_info(self, number):
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if not (0 <= number < self.num_sections):
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raise ValueError('Not a valid section number %i' % number)
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self.stream.seek(78 + number * 8)
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offset, a1, a2, a3, a4 = struct.unpack('>LBBBB', self.stream.read(8))[0]
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flags, val = a1, a2 << 16 | a3 << 8 | a4
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return (offset, flags, val)
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def section_offset(self, number):
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if not (0 <= number < self.num_sections):
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raise ValueError('Not a valid section number %i' % number)
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self.stream.seek(78 + number * 8)
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return struct.unpack('>LBBBB', self.stream.read(8))[0]
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def section_data(self, number):
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if not (0 <= number < self.num_sections):
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raise ValueError('Not a valid section number %i' % number)
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start = self.section_offset(number)
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if number == self.num_sections -1:
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self.stream.seek(0, 2)
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end = self.stream.tell()
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else:
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end = self.section_offset(number + 1)
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self.stream.seek(start)
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return self.stream.read(end - start)
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class PdbHeaderBuilder(object):
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def __init__(self, identity, title):
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self.identity = identity.ljust(3, '\x00')[:8].encode('utf-8')
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self.title = b'%s\x00' % re.sub('[^-A-Za-z0-9 ]+', '_', title).ljust(31, '\x00')[:31].encode('ascii', 'replace')
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def build_header(self, section_lengths, out_stream):
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'''
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section_lengths = Lenght of each section in file.
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'''
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now = int(time.time())
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nrecords = len(section_lengths)
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out_stream.write(self.title + struct.pack('>HHIIIIII', 0, 0, now, now, 0, 0, 0, 0))
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out_stream.write(self.identity + struct.pack('>IIH', nrecords, 0, nrecords))
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offset = 78 + (8 * nrecords) + 2
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for id, record in enumerate(section_lengths):
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out_stream.write(struct.pack('>LBBBB', long_type(offset), 0, 0, 0, 0))
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offset += record
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out_stream.write(b'\x00\x00')
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