Current File : //lib/calibre/calibre/ebooks/html/input.py
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
__docformat__ = 'restructuredtext en'
'''
Input plugin for HTML or OPF ebooks.
'''
import os, re, sys, errno as gerrno
from calibre.ebooks.oeb.base import urlunquote
from calibre.ebooks.chardet import detect_xml_encoding
from calibre.constants import iswindows
from calibre import unicode_path, as_unicode, replace_entities
from polyglot.urllib import urlparse, urlunparse
class Link:
'''
Represents a link in a HTML file.
'''
@classmethod
def url_to_local_path(cls, url, base):
path = url.path
isabs = False
if iswindows and path.startswith('/'):
path = path[1:]
isabs = True
path = urlunparse(('', '', path, url.params, url.query, ''))
path = urlunquote(path)
if isabs or os.path.isabs(path):
return path
return os.path.abspath(os.path.join(base, path))
def __init__(self, url, base):
'''
:param url: The url this link points to. Must be an unquoted unicode string.
:param base: The base folder that relative URLs are with respect to.
Must be a unicode string.
'''
assert isinstance(url, str) and isinstance(base, str)
self.url = url
self.parsed_url = urlparse(self.url)
self.is_local = self.parsed_url.scheme in ('', 'file')
self.is_internal = self.is_local and not bool(self.parsed_url.path)
self.path = None
self.fragment = urlunquote(self.parsed_url.fragment)
if self.is_local and not self.is_internal:
self.path = self.url_to_local_path(self.parsed_url, base)
def __hash__(self):
if self.path is None:
return hash(self.url)
return hash(self.path)
def __eq__(self, other):
return self.path == getattr(other, 'path', other)
def __str__(self):
return 'Link: %s --> %s'%(self.url, self.path)
class IgnoreFile(Exception):
def __init__(self, msg, errno):
Exception.__init__(self, msg)
self.doesnt_exist = errno == gerrno.ENOENT
self.errno = errno
class HTMLFile:
'''
Contains basic information about an HTML file. This
includes a list of links to other files as well as
the encoding of each file. Also tries to detect if the file is not a HTML
file in which case :member:`is_binary` is set to True.
The encoding of the file is available as :member:`encoding`.
'''
HTML_PAT = re.compile(r'<\s*html', re.IGNORECASE)
HTML_PAT_BIN = re.compile(br'<\s*html', re.IGNORECASE)
TITLE_PAT = re.compile('<title>([^<>]+)</title>', re.IGNORECASE)
LINK_PAT = re.compile(
r'<\s*a\s+.*?href\s*=\s*(?:(?:"(?P<url1>[^"]+)")|(?:\'(?P<url2>[^\']+)\')|(?P<url3>[^\s>]+))',
re.DOTALL|re.IGNORECASE)
def __init__(self, path_to_html_file, level, encoding, verbose, referrer=None):
'''
:param level: The level of this file. Should be 0 for the root file.
:param encoding: Use `encoding` to decode HTML.
:param referrer: The :class:`HTMLFile` that first refers to this file.
'''
self.path = unicode_path(path_to_html_file, abs=True)
self.title = os.path.splitext(os.path.basename(self.path))[0]
self.base = os.path.dirname(self.path)
self.level = level
self.referrer = referrer
self.links = []
try:
with open(self.path, 'rb') as f:
src = header = f.read(4096)
encoding = detect_xml_encoding(src)[1]
if encoding:
try:
header = header.decode(encoding, errors='replace')
except ValueError:
pass
self.is_binary = False
if level > 0:
pat = self.HTML_PAT_BIN if isinstance(header, bytes) else self.HTML_PAT
self.is_binary = not bool(pat.search(header))
if not self.is_binary:
src += f.read()
except OSError as err:
msg = 'Could not read from file: %s with error: %s'%(self.path, as_unicode(err))
if level == 0:
raise OSError(msg)
raise IgnoreFile(msg, err.errno)
if not src:
if level == 0:
raise ValueError('The file %s is empty'%self.path)
self.is_binary = True
if not self.is_binary:
if not encoding:
encoding = detect_xml_encoding(src[:4096], verbose=verbose)[1]
self.encoding = encoding
else:
self.encoding = encoding
src = src.decode(encoding, 'replace')
match = self.TITLE_PAT.search(src)
self.title = match.group(1) if match is not None else self.title
self.find_links(src)
def __eq__(self, other):
return self.path == getattr(other, 'path', other)
def __hash__(self):
return hash(self.path)
def __str__(self):
return 'HTMLFile:%d:%s:%r'%(self.level, 'b' if self.is_binary else 'a', self.path)
def __repr__(self):
return str(self)
def find_links(self, src):
for match in self.LINK_PAT.finditer(src):
url = None
for i in ('url1', 'url2', 'url3'):
url = match.group(i)
if url:
break
url = replace_entities(url)
try:
link = self.resolve(url)
except ValueError:
# Unparsable URL, ignore
continue
if link not in self.links:
self.links.append(link)
def resolve(self, url):
return Link(url, self.base)
def depth_first(root, flat, visited=None):
yield root
if visited is None:
visited = set()
visited.add(root)
for link in root.links:
if link.path is not None and link not in visited:
try:
index = flat.index(link)
except ValueError: # Can happen if max_levels is used
continue
hf = flat[index]
if hf not in visited:
yield hf
visited.add(hf)
for hf in depth_first(hf, flat, visited):
if hf not in visited:
yield hf
visited.add(hf)
def traverse(path_to_html_file, max_levels=sys.maxsize, verbose=0, encoding=None):
'''
Recursively traverse all links in the HTML file.
:param max_levels: Maximum levels of recursion. Must be non-negative. 0
implies that no links in the root HTML file are followed.
:param encoding: Specify character encoding of HTML files. If `None` it is
auto-detected.
:return: A pair of lists (breadth_first, depth_first). Each list contains
:class:`HTMLFile` objects.
'''
assert max_levels >= 0
level = 0
flat = [HTMLFile(path_to_html_file, level, encoding, verbose)]
next_level = list(flat)
while level < max_levels and len(next_level) > 0:
level += 1
nl = []
for hf in next_level:
rejects = []
for link in hf.links:
if link.path is None or link.path in flat:
continue
try:
nf = HTMLFile(link.path, level, encoding, verbose, referrer=hf)
if nf.is_binary:
raise IgnoreFile('%s is a binary file'%nf.path, -1)
nl.append(nf)
flat.append(nf)
except IgnoreFile as err:
rejects.append(link)
if not err.doesnt_exist or verbose > 1:
print(repr(err))
for link in rejects:
hf.links.remove(link)
next_level = list(nl)
orec = sys.getrecursionlimit()
sys.setrecursionlimit(500000)
try:
return flat, list(depth_first(flat[0], flat))
finally:
sys.setrecursionlimit(orec)
def get_filelist(htmlfile, dir, opts, log):
'''
Build list of files referenced by html file or try to detect and use an
OPF file instead.
'''
log.info('Building file list...')
filelist = traverse(htmlfile, max_levels=int(opts.max_levels),
verbose=opts.verbose,
encoding=opts.input_encoding)[0 if opts.breadth_first else 1]
if opts.verbose:
log.debug('\tFound files...')
for f in filelist:
log.debug('\t\t', f)
return filelist
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