def build_links(self, db):
""" Analyze the original page, and rebulid the link-relationship. """
print "Building links' connections."
conn = sqlite3.connect(db)
cur = conn.cursor()
conn.text_factory = str
dbname = db[:-3]
sql = "select url from %s" % dbname
urls = [ url[0] for url in cur.execute(sql).fetchall()]
urlids = self.urls2ids(urls)
from_urls = dict([(urlid,[]) for urlid in urlids])
to_urls = dict([(urlid,[]) for urlid in urlids])
progress = ProgressMeter(total=len(urls))
for (cnt, url) in enumerate(urls):
urlid = self.get_urlid(url)
p = MyHTMLParser(url)
sql = "select content from %s where url='%s'" % (dbname, url)
content = cur.execute(sql).fetchone()[0]
try: p.feed(content)
except: ferrmsg('Error: feed error in %s.' % url, 'Rank')
to_urls[urlid] = self.urls2ids(p.htm_urls())
for lid in to_urls[urlid]:
if lid not in from_urls.keys():
continue
else:
from_urls[lid].append(urlid)
# update the progress
if (cnt % REFRESH_CNT) == 0 or cnt == progress.total-1:
progress.update(cnt+1)
self.url_ids = urlids
self.from_ids = from_urls
self.to_ids = to_urls
def getitems(self, html):
""" Analyze the original webpage, and extract the valuable info.
Here only extract the page title and all page contents. """
try:
p = Parser()
p.feed(html)
except:
ferrmsg('Error: feed error!', 'Index')
items = {}
title = p.get_title()
items['title'] = title
content = p.get_content()
items['content'] = content
return items
def download(self):
""" Download a given url's page. """
try:
request = urllib2.Request(url=self.url, headers=self.headers)
page = self.opener.open(request)
if page.code == 200:
gzipdata = page.read()
gzipstream = StringIO(gzipdata)
try:
self.data = gzip.GzipFile(fileobj=gzipstream).read()
except IOError:
self.data = gzipdata
except:
ferrmsg('Error: invalid URL "%s"' % self.url, 'Spider')
self.data = RET_ERROR
return self.data
def query(self, q, op='and'):
""" Query and rank the results. Calculate the scores according to
both factors of the content rank and page rank.
Note: In this function, calculate the content rank scores in the real time
and only get the page rank scores which are preloaded in the database. """
db = self.config.indexdb
sort = int(self.config.sort)
cr_fac = float(self.config.rankers['content'])
pr_fac = float(self.config.rankers['page'])
query = SimpleQuery(db)
words = query.parse_query(q)
urls = query.query(q)
if len(urls) == 0:
return []
scores = {}
valid_fac = {}
valid_score = {}
if cr_fac > 0:
cr = ContentRanker(db, sort)
cr_scores = cr.score(urls, words)
cr_scores = normalize(cr_scores)
valid_fac['content'] = cr_fac
valid_score['content'] = cr_scores
if pr_fac > 0:
pr = PageRanker(db, sort)
pr_scores = pr.score(urls, words)
pr_scores = normalize(pr_scores)
valid_fac['page'] = pr_fac
valid_score['page'] = pr_scores
for urlid in urls:
scores[urlid] = 0.0
try:
for key in valid_fac.keys():
scores[urlid] += valid_fac[key]*valid_score[key][urlid]
except:
ferrmsg("Error: urlid(%s) is not find in the results of each rank." % urlid, \
'SECore')
res = sorted(scores.items(), key=lambda v:v[1], reverse=sort)
res = [t[0] for t in res]
return res
def get_page(self, url):
""" Download the page and analyze all the urls in this page. """
rer = Retriever(url, self.headers)
retval = rer.download()
if retval is RET_ERROR:
return retval
self.num_gets += 1
if url not in self.bloom:
self.bloom.add(url)
p = MyHTMLParser(url)
try:
p.feed(retval)
except:
ferrmsg('Error: feed error in url: %s' % url, 'Spider')
for link in p.htm_urls():
if (link not in self.bloom) and (link not in self.queue.queue):
self.queue.put(link)
return retval
