Current File : //usr/lib/calibre/calibre/ebooks/oeb/polish/split.py
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
import copy, os, re
from polyglot.builtins import string_or_bytes
from calibre.ebooks.oeb.base import barename, XPNSMAP, XPath, OPF, XHTML, OEB_DOCS
from calibre.ebooks.oeb.polish.errors import MalformedMarkup
from calibre.ebooks.oeb.polish.toc import node_from_loc
from calibre.ebooks.oeb.polish.replace import LinkRebaser
from polyglot.builtins import iteritems
from polyglot.urllib import urlparse
class AbortError(ValueError):
pass
def in_table(node):
while node is not None:
if node.tag.endswith('}table'):
return True
node = node.getparent()
return False
def adjust_split_point(split_point, log):
'''
Move the split point up its ancestor chain if it has no content
before it. This handles the common case:
<div id="chapter1"><h2>Chapter 1</h2>...</div> with a page break on the
h2.
'''
sp = split_point
while True:
parent = sp.getparent()
if (
parent is None or
barename(parent.tag) in {'body', 'html'} or
(parent.text and parent.text.strip()) or
parent.index(sp) > 0
):
break
sp = parent
if sp is not split_point:
log.debug('Adjusted split point to ancestor')
return sp
def get_body(root):
return root.find('h:body', namespaces=XPNSMAP)
def do_split(split_point, log, before=True):
'''
Split tree into a *before* and an *after* tree at ``split_point``.
:param split_point: The Element at which to split
:param before: If True tree is split before split_point, otherwise after split_point
:return: before_tree, after_tree
'''
if before:
# We cannot adjust for after since moving an after split point to a
# parent will cause breakage if the parent contains any content
# after the original split point
split_point = adjust_split_point(split_point, log)
tree = split_point.getroottree()
path = tree.getpath(split_point)
tree, tree2 = copy.deepcopy(tree), copy.deepcopy(tree)
root, root2 = tree.getroot(), tree2.getroot()
body, body2 = map(get_body, (root, root2))
split_point = root.xpath(path)[0]
split_point2 = root2.xpath(path)[0]
def nix_element(elem, top=True):
# Remove elem unless top is False in which case replace elem by its
# children
parent = elem.getparent()
if top:
parent.remove(elem)
else:
index = parent.index(elem)
parent[index:index+1] = list(elem.iterchildren())
# Tree 1
hit_split_point = False
keep_descendants = False
split_point_descendants = frozenset(split_point.iterdescendants())
for elem in tuple(body.iterdescendants()):
if elem is split_point:
hit_split_point = True
if before:
nix_element(elem)
else:
# We want to keep the descendants of the split point in
# Tree 1
keep_descendants = True
# We want the split point element, but not its tail
elem.tail = '\n'
continue
if hit_split_point:
if keep_descendants:
if elem in split_point_descendants:
# elem is a descendant keep it
continue
else:
# We are out of split_point, so prevent further set
# lookups of split_point_descendants
keep_descendants = False
nix_element(elem)
# Tree 2
ancestors = frozenset(XPath('ancestor::*')(split_point2))
for elem in tuple(body2.iterdescendants()):
if elem is split_point2:
if not before:
# Keep the split point element's tail, if it contains non-whitespace
# text
tail = elem.tail
if tail and not tail.isspace():
parent = elem.getparent()
idx = parent.index(elem)
if idx == 0:
parent.text = (parent.text or '') + tail
else:
sib = parent[idx-1]
sib.tail = (sib.tail or '') + tail
# Remove the element itself
nix_element(elem)
break
if elem in ancestors:
# We have to preserve the ancestors as they could have CSS
# styles that are inherited/applicable, like font or
# width. So we only remove the text, if any.
elem.text = '\n'
else:
nix_element(elem, top=False)
body2.text = '\n'
return tree, tree2
class SplitLinkReplacer:
def __init__(self, base, bottom_anchors, top_name, bottom_name, container):
self.bottom_anchors, self.bottom_name = bottom_anchors, bottom_name
self.container, self.top_name = container, top_name
self.base = base
self.replaced = False
def __call__(self, url):
if url and url.startswith('#'):
return url
name = self.container.href_to_name(url, self.base)
if name != self.top_name:
return url
purl = urlparse(url)
if purl.fragment and purl.fragment in self.bottom_anchors:
url = self.container.name_to_href(self.bottom_name, self.base) + '#' + purl.fragment
self.replaced = True
return url
def split(container, name, loc_or_xpath, before=True, totals=None):
'''
Split the file specified by name at the position specified by loc_or_xpath.
Splitting automatically migrates all links and references to the affected
files.
:param loc_or_xpath: Should be an XPath expression such as
//h:div[@id="split_here"]. Can also be a *loc* which is used internally to
implement splitting in the preview panel.
:param before: If True the split occurs before the identified element otherwise after it.
:param totals: Used internally
'''
root = container.parsed(name)
if isinstance(loc_or_xpath, str):
split_point = root.xpath(loc_or_xpath)[0]
else:
try:
split_point = node_from_loc(root, loc_or_xpath, totals=totals)
except MalformedMarkup:
# The webkit HTML parser and the container parser have yielded
# different node counts, this can happen if the file is valid XML
# but contains constructs like nested <p> tags. So force parse it
# with the HTML 5 parser and try again.
raw = container.raw_data(name)
root = container.parse_xhtml(raw, fname=name, force_html5_parse=True)
try:
split_point = node_from_loc(root, loc_or_xpath, totals=totals)
except MalformedMarkup:
raise MalformedMarkup(_('The file %s has malformed markup. Try running the Fix HTML tool'
' before splitting') % name)
container.replace(name, root)
if in_table(split_point):
raise AbortError('Cannot split inside tables')
if split_point.tag.endswith('}body'):
raise AbortError('Cannot split on the <body> tag')
tree1, tree2 = do_split(split_point, container.log, before=before)
root1, root2 = tree1.getroot(), tree2.getroot()
anchors_in_top = frozenset(root1.xpath('//*/@id')) | frozenset(root1.xpath('//*/@name')) | {''}
anchors_in_bottom = frozenset(root2.xpath('//*/@id')) | frozenset(root2.xpath('//*/@name'))
base, ext = name.rpartition('.')[0::2]
base = re.sub(r'_split\d+$', '', base)
nname, s = None, 0
while not nname or container.exists(nname):
s += 1
nname = '%s_split%d.%s' % (base, s, ext)
manifest_item = container.generate_item(nname, media_type=container.mime_map[name])
bottom_name = container.href_to_name(manifest_item.get('href'), container.opf_name)
# Fix links in the split trees
for r in (root1, root2):
for a in r.xpath('//*[@href]'):
url = a.get('href')
if url.startswith('#'):
fname = name
else:
fname = container.href_to_name(url, name)
if fname == name:
purl = urlparse(url)
if purl.fragment in anchors_in_top:
if r is root2:
a.set('href', f'{container.name_to_href(name, bottom_name)}#{purl.fragment}')
else:
a.set('href', '#' + purl.fragment)
elif purl.fragment in anchors_in_bottom:
if r is root1:
a.set('href', f'{container.name_to_href(bottom_name, name)}#{purl.fragment}')
else:
a.set('href', '#' + purl.fragment)
# Fix all links in the container that point to anchors in the bottom tree
for fname, media_type in iteritems(container.mime_map):
if fname not in {name, bottom_name}:
repl = SplitLinkReplacer(fname, anchors_in_bottom, name, bottom_name, container)
container.replace_links(fname, repl)
container.replace(name, root1)
container.replace(bottom_name, root2)
spine = container.opf_xpath('//opf:spine')[0]
for spine_item, spine_name, linear in container.spine_iter:
if spine_name == name:
break
index = spine.index(spine_item) + 1
si = spine.makeelement(OPF('itemref'), idref=manifest_item.get('id'))
if not linear:
si.set('linear', 'no')
container.insert_into_xml(spine, si, index=index)
container.dirty(container.opf_name)
return bottom_name
def multisplit(container, name, xpath, before=True):
'''
Split the specified file at multiple locations (all tags that match the specified XPath expression). See also: :func:`split`.
Splitting automatically migrates all links and references to the affected
files.
:param before: If True the splits occur before the identified element otherwise after it.
'''
root = container.parsed(name)
nodes = root.xpath(xpath, namespaces=XPNSMAP)
if not nodes:
raise AbortError(_('The expression %s did not match any nodes') % xpath)
for split_point in nodes:
if in_table(split_point):
raise AbortError('Cannot split inside tables')
if split_point.tag.endswith('}body'):
raise AbortError('Cannot split on the <body> tag')
for i, tag in enumerate(nodes):
tag.set('calibre-split-point', str(i))
current = name
all_names = [name]
for i in range(len(nodes)):
current = split(container, current, '//*[@calibre-split-point="%d"]' % i, before=before)
all_names.append(current)
for x in all_names:
for tag in container.parsed(x).xpath('//*[@calibre-split-point]'):
tag.attrib.pop('calibre-split-point')
container.dirty(x)
return all_names[1:]
class MergeLinkReplacer:
def __init__(self, base, anchor_map, master, container):
self.container, self.anchor_map = container, anchor_map
self.master = master
self.base = base
self.replaced = False
def __call__(self, url):
if url and url.startswith('#'):
return url
name = self.container.href_to_name(url, self.base)
amap = self.anchor_map.get(name, None)
if amap is None:
return url
purl = urlparse(url)
frag = purl.fragment or ''
frag = amap.get(frag, frag)
url = self.container.name_to_href(self.master, self.base) + '#' + frag
self.replaced = True
return url
def add_text(body, text):
if len(body) > 0:
body[-1].tail = (body[-1].tail or '') + text
else:
body.text = (body.text or '') + text
def all_anchors(root):
return set(root.xpath('//*/@id')) | set(root.xpath('//*/@name'))
def all_stylesheets(container, name):
for link in XPath('//h:head/h:link[@href]')(container.parsed(name)):
name = container.href_to_name(link.get('href'), name)
typ = link.get('type', 'text/css')
if typ == 'text/css':
yield name
def unique_anchor(seen_anchors, current):
c = 0
ans = current
while ans in seen_anchors:
c += 1
ans = '%s_%d' % (current, c)
return ans
def remove_name_attributes(root):
# Remove all name attributes, replacing them with id attributes
for elem in root.xpath('//*[@id and @name]'):
del elem.attrib['name']
for elem in root.xpath('//*[@name]'):
elem.set('id', elem.attrib.pop('name'))
def merge_html(container, names, master, insert_page_breaks=False):
p = container.parsed
root = p(master)
# Ensure master has a <head>
head = root.find('h:head', namespaces=XPNSMAP)
if head is None:
head = root.makeelement(XHTML('head'))
container.insert_into_xml(root, head, 0)
seen_anchors = all_anchors(root)
seen_stylesheets = set(all_stylesheets(container, master))
master_body = p(master).findall('h:body', namespaces=XPNSMAP)[-1]
master_base = os.path.dirname(master)
anchor_map = {n:{} for n in names if n != master}
first_anchor_map = {}
for name in names:
if name == master:
continue
# Insert new stylesheets into master
for sheet in all_stylesheets(container, name):
if sheet not in seen_stylesheets:
seen_stylesheets.add(sheet)
link = head.makeelement(XHTML('link'), rel='stylesheet', type='text/css', href=container.name_to_href(sheet, master))
container.insert_into_xml(head, link)
# Rebase links if master is in a different directory
if os.path.dirname(name) != master_base:
container.replace_links(name, LinkRebaser(container, name, master))
root = p(name)
children = []
for body in p(name).findall('h:body', namespaces=XPNSMAP):
children.append(body.text if body.text and body.text.strip() else '\n\n')
children.extend(body)
first_child = ''
for first_child in children:
if not isinstance(first_child, string_or_bytes):
break
if isinstance(first_child, string_or_bytes):
# body contained only text, no tags
first_child = body.makeelement(XHTML('p'))
first_child.text, children[0] = children[0], first_child
amap = anchor_map[name]
remove_name_attributes(root)
for elem in root.xpath('//*[@id]'):
val = elem.get('id')
if not val:
continue
if val in seen_anchors:
nval = unique_anchor(seen_anchors, val)
elem.set('id', nval)
amap[val] = nval
else:
seen_anchors.add(val)
if 'id' not in first_child.attrib:
first_child.set('id', unique_anchor(seen_anchors, 'top'))
seen_anchors.add(first_child.get('id'))
first_anchor_map[name] = first_child.get('id')
if insert_page_breaks:
first_child.set('style', first_child.get('style', '') + '; page-break-before: always')
amap[''] = first_child.get('id')
# Fix links that point to local changed anchors
for a in XPath('//h:a[starts-with(@href, "#")]')(root):
q = a.get('href')[1:]
if q in amap:
a.set('href', '#' + amap[q])
for child in children:
if isinstance(child, string_or_bytes):
add_text(master_body, child)
else:
master_body.append(copy.deepcopy(child))
container.remove_item(name, remove_from_guide=False)
# Fix all links in the container that point to merged files
for fname, media_type in iteritems(container.mime_map):
repl = MergeLinkReplacer(fname, anchor_map, master, container)
container.replace_links(fname, repl)
return first_anchor_map
def merge_css(container, names, master):
p = container.parsed
msheet = p(master)
master_base = os.path.dirname(master)
merged = set()
for name in names:
if name == master:
continue
# Rebase links if master is in a different directory
if os.path.dirname(name) != master_base:
container.replace_links(name, LinkRebaser(container, name, master))
sheet = p(name)
# Remove charset rules
cr = [r for r in sheet.cssRules if r.type == r.CHARSET_RULE]
[sheet.deleteRule(sheet.cssRules.index(r)) for r in cr]
for rule in sheet.cssRules:
msheet.add(rule)
container.remove_item(name)
merged.add(name)
# Remove links to merged stylesheets in the html files, replacing with a
# link to the master sheet
for name, mt in iteritems(container.mime_map):
if mt in OEB_DOCS:
removed = False
root = p(name)
for link in XPath('//h:link[@href]')(root):
q = container.href_to_name(link.get('href'), name)
if q in merged:
container.remove_from_xml(link)
removed = True
if removed:
container.dirty(name)
if removed and master not in set(all_stylesheets(container, name)):
head = root.find('h:head', namespaces=XPNSMAP)
if head is not None:
link = head.makeelement(XHTML('link'), type='text/css', rel='stylesheet', href=container.name_to_href(master, name))
container.insert_into_xml(head, link)
def merge(container, category, names, master):
'''
Merge the specified files into a single file, automatically migrating all
links and references to the affected files. The file must all either be HTML or CSS files.
:param category: Must be either ``'text'`` for HTML files or ``'styles'`` for CSS files
:param names: The list of files to be merged
:param master: Which of the merged files is the *master* file, that is, the file that will remain after merging.
'''
if category not in {'text', 'styles'}:
raise AbortError('Cannot merge files of type: %s' % category)
if len(names) < 2:
raise AbortError('Must specify at least two files to be merged')
if master not in names:
raise AbortError('The master file (%s) must be one of the files being merged' % master)
if category == 'text':
merge_html(container, names, master)
elif category == 'styles':
merge_css(container, names, master)
container.dirty(master)
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