Current File : //usr/lib/calibre/calibre/ebooks/metadata/ereader.py
'''
Read meta information from eReader pdb files.
'''
__license__ = 'GPL v3'
__copyright__ = '2009, John Schember <john@nachtimwald.com>'
__docformat__ = 'restructuredtext en'
import re
import struct
from calibre.ebooks.metadata import MetaInformation
from calibre.ebooks.metadata import authors_to_string
from calibre.ebooks.pdb.ereader.reader132 import HeaderRecord
from calibre.ebooks.pdb.header import PdbHeaderBuilder
from calibre.ebooks.pdb.header import PdbHeaderReader
def get_cover(pheader, eheader):
cover_data = None
for i in range(eheader.image_count):
raw = pheader.section_data(eheader.image_data_offset + i)
if raw[4:4 + 32].strip(b'\x00') == b'cover.png':
cover_data = raw[62:]
break
return ('png', cover_data)
def get_metadata(stream, extract_cover=True):
"""
Return metadata as a L{MetaInfo} object
"""
mi = MetaInformation(None, [_('Unknown')])
stream.seek(0)
pheader = PdbHeaderReader(stream)
# Only Dropbook produced 132 byte record0 files are supported
if len(pheader.section_data(0)) == 132:
hr = HeaderRecord(pheader.section_data(0))
if hr.compression in (2, 10) and hr.has_metadata == 1:
try:
mdata = pheader.section_data(hr.metadata_offset)
mdata = mdata.decode('cp1252', 'replace').split('\x00')
mi.title = re.sub(r'[^a-zA-Z0-9 \._=\+\-!\?,\'\"]', '', mdata[0])
mi.authors = [re.sub(r'[^a-zA-Z0-9 \._=\+\-!\?,\'\"]', '', mdata[1])]
mi.publisher = re.sub(r'[^a-zA-Z0-9 \._=\+\-!\?,\'\"]', '', mdata[3])
mi.isbn = re.sub(r'[^a-zA-Z0-9 \._=\+\-!\?,\'\"]', '', mdata[4])
except Exception:
pass
if extract_cover:
mi.cover_data = get_cover(pheader, hr)
if not mi.title:
mi.title = pheader.title if pheader.title else _('Unknown')
return mi
def set_metadata(stream, mi):
pheader = PdbHeaderReader(stream)
# Only Dropbook produced 132 byte record0 files are supported
if pheader.section_data(0) != 132:
return
sections = [pheader.section_data(x) for x in range(0, pheader.section_count())]
hr = HeaderRecord(sections[0])
if hr.compression not in (2, 10):
return
# Create a metadata record for the file if one does not already exist
if not hr.has_metadata:
sections += [b'', b'MeTaInFo\x00']
last_data = len(sections) - 1
for i in range(0, 132, 2):
val, = struct.unpack('>H', sections[0][i:i + 2])
if val >= hr.last_data_offset:
sections[0][i:i + 2] = struct.pack('>H', last_data)
sections[0][24:26] = struct.pack('>H', 1) # Set has metadata
sections[0][44:46] = struct.pack('>H', last_data - 1) # Set location of metadata
sections[0][52:54] = struct.pack('>H', last_data) # Ensure last data offset is updated
# Merge the metadata into the file
file_mi = get_metadata(stream, False)
file_mi.smart_update(mi)
sections[hr.metadata_offset] = ('{}\x00{}\x00{}\x00{}\x00{}\x00'.format(
file_mi.title, authors_to_string(file_mi.authors), '', file_mi.publisher, file_mi.isbn)).encode('cp1252', 'replace')
# Rebuild the PDB wrapper because the offsets have changed due to the
# new metadata.
pheader_builder = PdbHeaderBuilder(pheader.ident, pheader.title)
stream.seek(0)
stream.truncate(0)
pheader_builder.build_header([len(x) for x in sections], stream)
# Write the data back to the file
for item in sections:
stream.write(item)
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