def url_processing_pipeline(args, input_urls, sleeptime):
'''Aggregated functions to show a list and download and process an input list'''
input_urls = url_processing_checks(args.blacklist, input_urls)
# print list without further processing
if args.list:
for url in input_urls:
write_result(url, args) # print('\n'.join(input_urls))
return None
# build domain-aware processing list
domain_dict = dict()
while len(input_urls) > 0:
url = input_urls.pop()
domain_name = extract_domain(url)
if domain_name not in domain_dict:
domain_dict[domain_name] = []
domain_dict[domain_name].append(url)
# initialize file counter if necessary
if len(input_urls) > MAX_FILES_PER_DIRECTORY:
counter = 0
else:
counter = None
if len(domain_dict) <= 5:
backoff_dict = dict()
single_threaded_processing(domain_dict, backoff_dict, args, sleeptime,
counter)
else:
multi_threaded_processing(domain_dict, args, sleeptime, counter)
def multi_threaded_processing(domain_dict, args, sleeptime, counter):
'''Implement a multi-threaded processing algorithm'''
i = 0
backoff_dict = dict()
if args.parallel is not None:
download_threads = args.parallel
else:
download_threads = DOWNLOAD_THREADS
while len(domain_dict) > 0:
# the remaining list is too small, process it differently
if len({x
for v in domain_dict.values() for x in v}) < download_threads:
single_threaded_processing(domain_dict, backoff_dict, args,
sleeptime, counter)
return
# populate buffer
bufferlist, bufferdomains = list(), set()
while len(bufferlist) < download_threads:
domain = random.choice(list(domain_dict.keys()))
if domain not in backoff_dict or \
(datetime.now() - backoff_dict[domain]).total_seconds() > sleeptime:
bufferlist.append(domain_dict[domain].pop())
bufferdomains.add(domain)
backoff_dict[domain] = datetime.now()
# safeguard
else:
i += 1
if i > len(domain_dict) * 3:
LOGGER.debug('spacing request for domain name %s', domain)
sleep(sleeptime)
i = 0
# start several threads
with ThreadPoolExecutor(max_workers=download_threads) as executor:
future_to_url = {
executor.submit(fetch_url, url): url
for url in bufferlist
}
for future in as_completed(future_to_url):
url = future_to_url[future]
# register in backoff dictionary to ensure time between requests
domain = extract_domain(url)
backoff_dict[domain] = datetime.now()
# handle result
counter = process_result(future.result(), args, url, counter)
# clean registries
for domain in bufferdomains:
if not domain_dict[domain]:
del domain_dict[domain]
del backoff_dict[domain]
def sitemap_search(url):
domain = extract_domain(url)
sitemapurl = url.rstrip('/') + '/sitemap.xml'
sitemapurls, linklist = process_sitemap(sitemapurl, domain)
if sitemapurls == [] and len(linklist) > 0:
return linklist
if sitemapurls == [] and linklist == []:
for sitemapurl in find_robots_sitemaps(url):
tmp_sitemapurls, tmp_linklist = process_sitemap(url, domain)
sitemapurls.extend(tmp_sitemapurls)
linklist.extend(tmp_linklist)
while sitemapurls:
tmp_sitemapurls, tmp_linklist = process_sitemap(
sitemapurls.pop(), domain)
sitemapurls.extend(tmp_sitemapurls)
linklist.extend(tmp_linklist)
return linklist
def extract_metadata(filecontent, default_url=None, date_config=None):
'''Main process for metadata extraction'''
# load contents
tree = load_html(filecontent)
if tree is None:
return None
# initialize dict and try to strip meta tags
metadata = examine_meta(tree)
# correction: author not a name
if metadata['author'] is not None:
if ' ' not in metadata['author'] or metadata['author'].startswith(
'http'):
metadata['author'] = None
# fix: try json-ld metadata and override
metadata = extract_json(tree, metadata)
# try with x-paths
# title
if metadata['title'] is None:
metadata['title'] = extract_title(tree)
# author
if metadata['author'] is None:
metadata['author'] = extract_author(tree)
# url
if metadata['url'] is None:
metadata['url'] = extract_url(tree, default_url)
# hostname
if metadata['url'] is not None:
metadata['hostname'] = extract_domain(metadata['url'])
# extract date with external module htmldate
if date_config is None:
date_config = HTMLDATE_CONFIG
date_config['url'] = metadata['url']
try:
metadata['date'] = find_date(tree, **date_config)
# temporary fix for htmldate bug
except UnicodeError:
pass
# sitename
if metadata['sitename'] is None:
metadata['sitename'] = extract_sitename(tree)
if metadata['sitename'] is not None:
if metadata['sitename'].startswith('@'):
# scrap Twitter ID
metadata['sitename'] = re.sub(r'^@', '', metadata['sitename'])
# capitalize
try:
if not '.' in metadata['sitename'] and not metadata['sitename'][
0].isupper():
metadata['sitename'] = metadata['sitename'].title()
# fix for empty name
except IndexError:
pass
else:
# use URL
if metadata['url']:
mymatch = re.match(r'https?://(?:www\.|w[0-9]+\.)?([^/]+)',
metadata['url'])
if mymatch:
metadata['sitename'] = mymatch.group(1)
# categories
if not metadata['categories']:
metadata['categories'] = extract_catstags('category', tree)
# tags
if not metadata['tags']:
metadata['tags'] = extract_catstags('tags', tree)
# for safety: length check
for key, value in metadata.items():
if value is not None and len(value) > 10000:
metadata[key] = value[:9999] + '…'
# return
return metadata
def extract_metadata(filecontent, default_url=None, date_config=None):
"""Main process for metadata extraction.
Args:
filecontent: HTML code as string.
default_url: Previously known URL of the downloaded document.
date_config: Provide extraction parameters to htmldate as dict().
Returns:
A dict() containing the extracted metadata information or None.
"""
# load contents
tree = load_html(filecontent)
if tree is None:
return None
# initialize dict and try to strip meta tags
metadata = examine_meta(tree)
# correction: author not a name
if metadata['author'] is not None:
if ' ' not in metadata['author'] or metadata['author'].startswith(
'http'):
metadata['author'] = None
# fix: try json-ld metadata and override
metadata = extract_json(tree, metadata)
# try with x-paths
# title
if metadata['title'] is None:
metadata['title'] = extract_title(tree)
# author
if metadata['author'] is None:
metadata['author'] = extract_author(tree)
# url
if metadata['url'] is None:
metadata['url'] = extract_url(tree, default_url)
# hostname
if metadata['url'] is not None:
metadata['hostname'] = extract_domain(metadata['url'])
# extract date with external module htmldate
if date_config is None:
date_config = HTMLDATE_CONFIG
date_config['url'] = metadata['url']
try:
metadata['date'] = find_date(tree, **date_config)
# temporary fixes for htmldate bugs # todo: remove later
except (TypeError, UnicodeError):
pass
# sitename
if metadata['sitename'] is None:
metadata['sitename'] = extract_sitename(tree)
if metadata['sitename'] is not None:
if metadata['sitename'].startswith('@'):
# scrap Twitter ID
metadata['sitename'] = re.sub(r'^@', '', metadata['sitename'])
# capitalize
try:
if not '.' in metadata['sitename'] and not metadata['sitename'][
0].isupper():
metadata['sitename'] = metadata['sitename'].title()
# fix for empty name
except IndexError:
pass
else:
# use URL
if metadata['url']:
mymatch = re.match(r'https?://(?:www\.|w[0-9]+\.)?([^/]+)',
metadata['url'])
if mymatch:
metadata['sitename'] = mymatch.group(1)
# categories
if not metadata['categories']:
metadata['categories'] = extract_catstags('category', tree)
# tags
if not metadata['tags']:
metadata['tags'] = extract_catstags('tags', tree)
# license
for element in tree.xpath('//a[@rel="license"]', ):
if element.text is not None:
metadata['license'] = trim(element.text)
break
# for safety: length check
for key, value in metadata.items():
if value is not None and len(value) > 10000:
metadata[key] = value[:9999] + '…'
# remove spaces and control characters
for item in metadata:
if metadata[item] is not None and isinstance(metadata[item], str):
metadata[item] = line_processing(metadata[item])
# return
return metadata
def extract_metadata(filecontent, default_url=None, date_config=None, fastmode=False, author_blacklist=None):
"""Main process for metadata extraction.
Args:
filecontent: HTML code as string.
default_url: Previously known URL of the downloaded document.
date_config: Provide extraction parameters to htmldate as dict().
author_blacklist: Provide a blacklist of Author Names as set() to filter out authors.
Returns:
A dict() containing the extracted metadata information or None.
"""
# init
if author_blacklist is None:
author_blacklist = set()
# load contents
tree = load_html(filecontent)
if tree is None:
return None
# initialize dict and try to strip meta tags
metadata = examine_meta(tree)
# to check: remove it and replace with author_blacklist in test case
if metadata.author is not None and ' ' not in metadata.author:
metadata.author = None
# fix: try json-ld metadata and override
try:
metadata = extract_meta_json(tree, metadata)
# todo: fix bugs in json_metadata.py
except TypeError as err:
LOGGER.warning('error in JSON metadata extraction: %s', err)
# try with x-paths
# title
if metadata.title is None:
metadata.title = extract_title(tree)
# check author in blacklist
if metadata.author is not None and len(author_blacklist) > 0:
metadata.author = check_authors(metadata.author, author_blacklist)
# author
if metadata.author is None:
metadata.author = extract_author(tree)
# recheck author in blacklist
if metadata.author is not None and len(author_blacklist) > 0:
metadata.author = check_authors(metadata.author, author_blacklist)
# url
if metadata.url is None:
metadata.url = extract_url(tree, default_url)
# hostname
if metadata.url is not None:
metadata.hostname = extract_domain(metadata.url)
# extract date with external module htmldate
if date_config is None:
# decide on fast mode
if fastmode is False:
date_config = HTMLDATE_CONFIG_EXTENSIVE
else:
date_config = HTMLDATE_CONFIG_FAST
date_config['url'] = metadata.url
metadata.date = find_date(tree, **date_config)
# sitename
if metadata.sitename is None:
metadata.sitename = extract_sitename(tree)
if metadata.sitename is not None:
if metadata.sitename.startswith('@'):
# scrap Twitter ID
metadata.sitename = re.sub(r'^@', '', metadata.sitename)
# capitalize
try:
if (
'.' not in metadata.sitename
and not metadata.sitename[0].isupper()
):
metadata.sitename = metadata.sitename.title()
# fix for empty name
except IndexError as err:
LOGGER.warning('error in sitename extraction: %s', err)
# use URL
elif metadata.url:
mymatch = re.match(r'https?://(?:www\.|w[0-9]+\.)?([^/]+)', metadata.url)
if mymatch:
metadata.sitename = mymatch.group(1)
# categories
if not metadata.categories:
metadata.categories = extract_catstags('category', tree)
# tags
if not metadata.tags:
metadata.tags = extract_catstags('tag', tree)
# license
metadata.license = extract_license(tree)
# safety checks
metadata.clean_and_trim()
# return result
return metadata
def determine_domain(url):
'''Extraction of domain/host name from URL via courlan module'''
domain = extract_domain(url)
return domain
