GwR revise layout analysis

This commit is contained in:
GRiker 2010-03-10 12:06:59 -07:00
parent 834fd93bc8
commit f500bca0fe

View File

@ -4,9 +4,10 @@ __copyright__ = '2010, Greg Riker <griker@hotmail.com>'
__docformat__ = 'restructuredtext en'
''' Read/write metadata from Amazon's topaz format '''
import copy, StringIO
import copy, StringIO, sys
from struct import pack, unpack
from calibre import prints
from calibre.ebooks.metadata import MetaInformation
def read_record(raw, name):
@ -253,7 +254,8 @@ class MetadataUpdater(object):
offset = 5
topaz_headers = {}
dkey_offset = 0
highest_payload_offset = 0
lowest_payload_offset = sys.maxint
lowest_offset_err = None
for x in range(self.header_records):
marker = self.data[offset]
offset += 1
@ -268,10 +270,10 @@ class MetadataUpdater(object):
hdr_offset, consumed = self.decode_vwi(self.data[offset:offset+4])
if tag == 'dkey':
dkey_offset = hdr_offset
if tag != 'metadata':
if hdr_offset > highest_payload_offset:
highest_payload_offset = hdr_offset
#print "adjusting highest_payload_offset to 0x%x (%s)" % (hdr_offset,tag)
if tag not in ['dkey','metadata']:
if hdr_offset < lowest_payload_offset:
lowest_payload_offset = hdr_offset
lowest_offset_err = "lowest_payload_offset: 0x%x (%s)" % (hdr_offset,tag)
offset += consumed
len_uncomp, consumed = self.decode_vwi(self.data[offset:offset+4])
offset += consumed
@ -280,10 +282,13 @@ class MetadataUpdater(object):
blocks[val] = dict(hdr_offset=hdr_offset,len_uncomp=len_uncomp,len_comp=len_comp)
topaz_headers[x] = dict(tag=tag,blocks=blocks)
self.topaz_headers = topaz_headers
self.highest_payload_offset = highest_payload_offset
self.eod = self.data[offset]
offset += 1
self.base = offset
self.lowest_payload_offset = lowest_payload_offset + self.base
if self.lowest_payload_offset < self.md_header_offset:
prints("Unexpected TPZ file layout:\n %s\n metadata_offset: 0x%x" % (lowest_offset_err, self.md_header_offset))
prints("metadata needs to be before payload")
self.base_value = None
if dkey_offset:
self.base_value = self.data[offset:offset + dkey_offset]
@ -352,8 +357,8 @@ class MetadataUpdater(object):
self.metadata[item]['metadata'] = value
return
if self.md_start > self.highest_payload_offset:
raise ValueError('Unable to update metadata')
if self.md_start > self.lowest_payload_offset:
raise ValueError('Unable to update metadata:')
try:
from calibre.ebooks.conversion.config import load_defaults
@ -386,7 +391,6 @@ class MetadataUpdater(object):
self.stream.write(updated_metadata)
self.stream.write(tail)
def set_metadata(stream, mi):
mu = MetadataUpdater(stream)
mu.update(mi)