Current File : //usr/lib/calibre/calibre/ebooks/pdb/ereader/reader202.py
'''
Read content from ereader pdb file with a 116 and 202 byte header created by Makebook.
'''
__license__ = 'GPL v3'
__copyright__ = '2009, John Schember <john@nachtimwald.com>'
__docformat__ = 'restructuredtext en'
import os
import struct
from calibre import CurrentDir
from calibre.ebooks.metadata.opf2 import OPFCreator
from calibre.ebooks.pdb.ereader import EreaderError
from calibre.ebooks.pdb.formatreader import FormatReader
from polyglot.builtins import as_unicode
class HeaderRecord:
'''
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.non_text_offset, = struct.unpack('>H', raw[8:10])
self.num_text_pages = self.non_text_offset - 1
class Reader202(FormatReader):
def __init__(self, header, stream, log, options):
self.log = log
self.encoding = options.input_encoding
self.log.debug('202 byte header version found.')
self.sections = []
for i in range(header.num_sections):
self.sections.append(header.section_data(i))
self.header_record = HeaderRecord(self.section_data(0))
if self.header_record.version not in (2, 4):
raise EreaderError('Unknown book version %i.' % self.header_record.version)
from calibre.ebooks.metadata.pdb import get_metadata
self.mi = get_metadata(stream, False)
def section_data(self, number):
return self.sections[number]
def decompress_text(self, number):
from calibre.ebooks.compression.palmdoc import decompress_doc
data = bytearray(self.section_data(number))
data = bytes(bytearray(x ^ 0xA5 for x in data))
return decompress_doc(data).decode(self.encoding or 'cp1252', 'replace')
def get_image(self, number):
name = None
img = None
data = self.section_data(number)
if data.startswith(b'PNG'):
name = data[4:4 + 32].strip(b'\x00')
img = data[62:]
return name, img
def get_text_page(self, number):
'''
Only palmdoc compression is supported. The text is xored with 0xA5 and
assumed to be encoded as Windows-1252. The encoding is part of
the eReader file spec and should always be this encoding.
'''
if not (1 <= number <= self.header_record.num_text_pages):
return ''
return self.decompress_text(number)
def extract_content(self, output_dir):
from calibre.ebooks.pml.pmlconverter import pml_to_html
output_dir = os.path.abspath(output_dir)
if not os.path.exists(output_dir):
os.makedirs(output_dir)
pml = ''
for i in range(1, self.header_record.num_text_pages + 1):
self.log.debug('Extracting text page %i' % i)
pml += self.get_text_page(i)
title = self.mi.title
if not isinstance(title, str):
title = title.decode('utf-8', 'replace')
html = '<html><head><title>%s</title></head><body>%s</body></html>' % \
(title, pml_to_html(pml))
with CurrentDir(output_dir):
with open('index.html', 'wb') as index:
self.log.debug('Writing text to index.html')
index.write(html.encode('utf-8'))
if not os.path.exists(os.path.join(output_dir, 'images/')):
os.makedirs(os.path.join(output_dir, 'images/'))
images = []
with CurrentDir(os.path.join(output_dir, 'images/')):
for i in range(self.header_record.non_text_offset, len(self.sections)):
name, img = self.get_image(i)
if name:
name = as_unicode(name)
images.append(name)
with open(name, 'wb') as imgf:
self.log.debug('Writing image %s to images/' % name)
imgf.write(img)
opf_path = self.create_opf(output_dir, images)
return opf_path
def create_opf(self, output_dir, images):
with CurrentDir(output_dir):
opf = OPFCreator(output_dir, self.mi)
manifest = [('index.html', None)]
for i in images:
manifest.append((os.path.join('images/', i), None))
opf.create_manifest(manifest)
opf.create_spine(['index.html'])
with open('metadata.opf', 'wb') as opffile:
opf.render(opffile)
return os.path.join(output_dir, 'metadata.opf')
def dump_pml(self):
'''
This is primarily used for debugging and 3rd party tools to
get the plm markup that comprises the text in the file.
'''
pml = ''
for i in range(1, self.header_record.num_text_pages + 1):
pml += self.get_text_page(i)
return pml
def dump_images(self, output_dir):
'''
This is primarily used for debugging and 3rd party tools to
get the images in the file.
'''
if not os.path.exists(output_dir):
os.makedirs(output_dir)
with CurrentDir(output_dir):
for i in range(0, self.header_record.num_image_pages):
name, img = self.get_image(self.header_record.image_data_offset + i)
with open(name, 'wb') as imgf:
imgf.write(img)
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