Initial import

ebook_converter/ebooks/pdb/ztxt/reader.py

@@ -0,0 +1,94 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+'''
+Read content from ztxt pdb file.
+'''
+
+__license__   = 'GPL v3'
+__copyright__ = '2009, John Schember <john@nachtimwald.com>'
+__docformat__ = 'restructuredtext en'
+
+import struct
+import zlib
+import io
+
+
+from calibre.ebooks.pdb.formatreader import FormatReader
+from calibre.ebooks.pdb.ztxt import zTXTError
+
+SUPPORTED_VERSION = (1, 40)
+
+
+class HeaderRecord(object):
+    '''
+    The first record in the file is always the header record. It holds
+    information related to the location of text, images, and so on
+    in the file. This is used in conjunction with the sections
+    defined in the file header.
+    '''
+
+    def __init__(self, raw):
+        self.version, = struct.unpack('>H', raw[0:2])
+        self.num_records, = struct.unpack('>H', raw[2:4])
+        self.size, = struct.unpack('>L', raw[4:8])
+        self.record_size, = struct.unpack('>H', raw[8:10])
+        self.flags, = struct.unpack('>B', raw[18:19])
+
+
+class Reader(FormatReader):
+
+    def __init__(self, header, stream, log, options):
+        self.stream = stream
+        self.log = log
+        self.options = options
+
+        self.sections = []
+        for i in range(header.num_sections):
+            self.sections.append(header.section_data(i))
+
+        self.header_record = HeaderRecord(self.section_data(0))
+
+        vmajor = (self.header_record.version & 0x0000FF00) >> 8
+        vminor = self.header_record.version & 0x000000FF
+        if vmajor < 1 or (vmajor == 1 and vminor < 40):
+            raise zTXTError('Unsupported ztxt version (%i.%i). Only versions newer than %i.%i are supported.' %
+                            (vmajor, vminor, SUPPORTED_VERSION[0], SUPPORTED_VERSION[1]))
+
+        if (self.header_record.flags & 0x01) == 0:
+            raise zTXTError('Only compression method 1 (random access) is supported')
+
+        self.log.debug('Foud ztxt version: %i.%i' % (vmajor, vminor))
+
+        # Initalize the decompressor
+        self.uncompressor = zlib.decompressobj()
+        self.uncompressor.decompress(self.section_data(1))
+
+    def section_data(self, number):
+        return self.sections[number]
+
+    def decompress_text(self, number):
+        if number == 1:
+            self.uncompressor = zlib.decompressobj()
+        return self.uncompressor.decompress(self.section_data(number))
+
+    def extract_content(self, output_dir):
+        raw_txt = b''
+
+        self.log.info('Decompressing text...')
+        for i in range(1, self.header_record.num_records + 1):
+            self.log.debug('\tDecompressing text section %i' % i)
+            raw_txt += self.decompress_text(i)
+
+        self.log.info('Converting text to OEB...')
+        stream = io.BytesIO(raw_txt)
+
+        from calibre.customize.ui import plugin_for_input_format
+
+        txt_plugin = plugin_for_input_format('txt')
+        for opt in txt_plugin.options:
+            if not hasattr(self.options, opt.option.name):
+                setattr(self.options, opt.option.name, opt.recommended_value)
+
+        stream.seek(0)
+        return txt_plugin.convert(stream, self.options, 'txt', self.log, {})