Current File : //usr/lib/calibre/calibre/ebooks/oeb/iterator/spine.py
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2012, Kovid Goyal <kovid@kovidgoyal.net>'
__docformat__ = 'restructuredtext en'
import re, os
from functools import partial
from operator import attrgetter
from collections import namedtuple
from calibre import guess_type, replace_entities
from calibre.ebooks.chardet import xml_to_unicode
def character_count(html):
''' Return the number of "significant" text characters in a HTML string. '''
count = 0
strip_space = re.compile(r'\s+')
for match in re.finditer(r'>[^<]+<', html):
count += len(strip_space.sub(' ', match.group()))-2
return count
def anchor_map(html):
''' Return map of all anchor names to their offsets in the html '''
ans = {}
for match in re.finditer(
r'''(?:id|name)\s*=\s*['"]([^'"]+)['"]''', html):
anchor = match.group(1)
ans[anchor] = ans.get(anchor, match.start())
return ans
def all_links(html):
''' Return set of all links in the file '''
ans = set()
for match in re.finditer(
r'''<\s*[Aa]\s+.*?[hH][Rr][Ee][Ff]\s*=\s*(['"])(.+?)\1''', html, re.MULTILINE|re.DOTALL):
ans.add(replace_entities(match.group(2)))
return ans
class SpineItem(str):
def __new__(cls, path, mime_type=None, read_anchor_map=True,
run_char_count=True, from_epub=False, read_links=True):
ppath = path.partition('#')[0]
if not os.path.exists(path) and os.path.exists(ppath):
path = ppath
obj = super().__new__(cls, path)
with lopen(path, 'rb') as f:
raw = f.read()
if from_epub:
# According to the spec, HTML in EPUB must be encoded in utf-8 or
# utf-16. Furthermore, there exist epub files produced by the usual
# incompetents that have utf-8 encoded HTML files that contain
# incorrect encoding declarations. See
# http://www.idpf.org/epub/20/spec/OPS_2.0.1_draft.htm#Section1.4.1.2
# http://www.idpf.org/epub/30/spec/epub30-publications.html#confreq-xml-enc
# https://bugs.launchpad.net/bugs/1188843
# So we first decode with utf-8 and only if that fails we try xml_to_unicode. This
# is the same algorithm as that used by the conversion pipeline (modulo
# some BOM based detection). Sigh.
try:
raw, obj.encoding = raw.decode('utf-8'), 'utf-8'
except UnicodeDecodeError:
raw, obj.encoding = xml_to_unicode(raw)
else:
raw, obj.encoding = xml_to_unicode(raw)
obj.character_count = character_count(raw) if run_char_count else 10000
obj.anchor_map = anchor_map(raw) if read_anchor_map else {}
obj.all_links = all_links(raw) if read_links else set()
obj.verified_links = set()
obj.start_page = -1
obj.pages = -1
obj.max_page = -1
obj.index_entries = []
if mime_type is None:
mime_type = guess_type(obj)[0]
obj.mime_type = mime_type
obj.is_single_page = None
return obj
class IndexEntry:
def __init__(self, spine, toc_entry, num):
self.num = num
self.text = toc_entry.text or _('Unknown')
self.key = toc_entry.abspath
self.anchor = self.start_anchor = toc_entry.fragment or None
try:
self.spine_pos = spine.index(self.key)
except ValueError:
self.spine_pos = -1
self.anchor_pos = 0
if self.spine_pos > -1:
self.anchor_pos = spine[self.spine_pos].anchor_map.get(self.anchor,
0)
self.depth = 0
p = toc_entry.parent
while p is not None:
self.depth += 1
p = p.parent
self.sort_key = (self.spine_pos, self.anchor_pos)
self.spine_count = len(spine)
def find_end(self, all_entries):
potential_enders = [i for i in all_entries if
i.depth <= self.depth and
(
(i.spine_pos == self.spine_pos and i.anchor_pos > self.anchor_pos) or
i.spine_pos > self.spine_pos
)]
if potential_enders:
# potential_enders is sorted by (spine_pos, anchor_pos)
end = potential_enders[0]
self.end_spine_pos = end.spine_pos
self.end_anchor = end.anchor
else:
self.end_spine_pos = self.spine_count - 1
self.end_anchor = None
def create_indexing_data(spine, toc):
if not toc:
return
f = partial(IndexEntry, spine)
index_entries = list(map(f,
(t for t in toc.flat() if t is not toc),
(i-1 for i, t in enumerate(toc.flat()) if t is not toc)
))
index_entries.sort(key=attrgetter('sort_key'))
[i.find_end(index_entries) for i in index_entries]
ie = namedtuple('IndexEntry', 'entry start_anchor end_anchor')
for spine_pos, spine_item in enumerate(spine):
for i in index_entries:
if i.end_spine_pos < spine_pos or i.spine_pos > spine_pos:
continue # Does not touch this file
start = i.anchor if i.spine_pos == spine_pos else None
end = i.end_anchor if i.spine_pos == spine_pos else None
spine_item.index_entries.append(ie(i, start, end))
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