Always use connection pooling.

dosagelib/comic.py

@@ -17,12 +17,13 @@ class FetchComicError(IOError):
 class ComicStrip(object):
     """A list of comic image URLs."""
 
-    def __init__(self, name, stripUrl, imageUrls, namer):
+    def __init__(self, name, stripUrl, imageUrls, namer, session):
         """Store the image URL list."""
         self.name = name
         self.stripUrl = stripUrl
         self.imageUrls = imageUrls
         self.namer = namer
+        self.session = session
 
     def getImages(self):
         """Get a list of image downloaders."""
@@ -35,13 +36,15 @@ class ComicStrip(object):
         if filename is None:
             filename = url.rsplit('/', 1)[1]
         dirname = getDirname(self.name)
-        return ComicImage(self.name, url, self.stripUrl, dirname, filename)
+        return ComicImage(self.name, url, self.stripUrl, dirname, filename, self.session)
 
 
 class ComicImage(object):
     """A comic image downloader."""
 
-    def __init__(self, name, url, referrer, dirname, filename):
+    ChunkBytes = 1024 * 100 # 100KB
+
+    def __init__(self, name, url, referrer, dirname, filename, session):
         """Set URL and filename."""
         self.name = name
         self.referrer = referrer
@@ -49,11 +52,12 @@ class ComicImage(object):
         self.dirname = dirname
         filename = getFilename(filename)
         self.filename, self.ext = os.path.splitext(filename)
+        self.session = session
 
     def connect(self):
         """Connect to host and get meta information."""
         try:
-            self.urlobj = getImageObject(self.url, self.referrer)
+            self.urlobj = getImageObject(self.url, self.referrer, self.session)
         except IOError as msg:
             raise FetchComicError('Unable to retrieve URL.', self.url, msg)
 
@@ -100,7 +104,8 @@ class ComicImage(object):
         try:
             out.debug('Writing comic to file %s...' % fn)
             with open(fn, 'wb') as comicOut:
-                comicOut.write(self.urlobj.content)
+                for chunk in self.urlobj.iter_content(chunk_size=self.ChunkBytes):
+                    comicOut.write(chunk)
             self.touch(fn)
         except Exception:
             if os.path.isfile(fn):

dosagelib/helpers.py

@@ -29,9 +29,9 @@ def bounceStarter(url, nextSearch):
     @classmethod
     def _starter(cls):
         """Get bounced start URL."""
-        data, baseUrl = getPageContent(url, session=cls.session)
+        data, baseUrl = getPageContent(url, cls.session)
         url1 = fetchUrl(url, data, baseUrl, cls.prevSearch)
-        data, baseUrl = getPageContent(url1, session=cls.session)
+        data, baseUrl = getPageContent(url1, cls.session)
         return fetchUrl(url1, data, baseUrl, nextSearch)
     return _starter
 
@@ -41,6 +41,6 @@ def indirectStarter(url, latestSearch):
     @classmethod
     def _starter(cls):
         """Get indirect start URL."""
-        data, baseUrl = getPageContent(url, session=cls.session)
+        data, baseUrl = getPageContent(url, cls.session)
         return fetchUrl(url, data, baseUrl, latestSearch)
     return _starter

dosagelib/plugins/clonemanga.py

@@ -25,14 +25,14 @@ def add(name, shortName, imageFolder=None, lastStrip=None):
     @classmethod
     def _starter(cls):
         # first, try hopping to previous and next comic
-        data, _baseUrl = getPageContent(baseUrl, session=cls.session)
+        data, _baseUrl = getPageContent(baseUrl, cls.session)
         try:
             url = fetchUrl(baseUrl, data, _baseUrl, _prevSearch)
         except ValueError:
             # no previous link found, try hopping to last comic
             return fetchUrl(baseUrl, data, _baseUrl, _lastSearch)
         else:
-            data, _baseUrl = getPageContent(url, session=cls.session)
+            data, _baseUrl = getPageContent(url, cls.session)
             return fetchUrl(url, data, _baseUrl, _nextSearch)
 
     attrs = dict(

dosagelib/plugins/drunkduck.py

@@ -26,14 +26,14 @@ def add(name, path):
     @classmethod
     def _starter(cls):
         # first, try hopping to previous and next comic
-        data, baseUrl = getPageContent(_url, session=cls.session)
+        data, baseUrl = getPageContent(_url, cls.session)
         try:
             url = fetchUrl(_url, data, baseUrl, _prevSearch)
         except ValueError:
             # no previous link found, try hopping to last comic
             return fetchUrl(_url, data, baseUrl, _lastSearch)
         else:
-            data, baseUrl = getPageContent(url, session=cls.session)
+            data, baseUrl = getPageContent(url, cls.session)
             return fetchUrl(url, data, baseUrl, _nextSearch)
 
     globals()[classname] = make_scraper(classname,

dosagelib/plugins/smackjeeves.py

@@ -31,10 +31,10 @@ def add(name, url, description, adult, bounce):
     def _starter(cls):
         """Get start URL."""
         url1 = modifier(url)
-        data, baseUrl = getPageContent(url1, session=cls.session)
+        data, baseUrl = getPageContent(url1, cls.session)
         url2 = fetchUrl(url1, data, baseUrl, cls.prevSearch)
         if bounce:
-            data, baseUrl = getPageContent(url2, session=cls.session)
+            data, baseUrl = getPageContent(url2, cls.session)
             url3 = fetchUrl(url2, data, baseUrl, _nextSearch)
             return modifier(url3)
         return modifier(url2)

dosagelib/plugins/universal.py

@@ -26,7 +26,7 @@ def add(name, shortname):
          <img alt="Marmaduke" src="http://assets.amuniversal.com/07e7f270fa08012ff506001dd8b71c47" />
          <h4>published: Sunday, November 11, 2012</h4>
         """
-        data = getPageContent(pageUrl)[0]
+        data = getPageContent(pageUrl, cls.session)[0]
         ro = compile(tagre("img", "src", escape(imageUrl)) + r'\s+<h4>published: ([^<]+)')
         mo = ro.search(data)
         if mo:

dosagelib/scraper.py

@@ -62,7 +62,7 @@ class _BasicScraper(object):
 
     def getStrip(self, url):
         """Get comic strip for given URL."""
-        data, baseUrl = getPageContent(url, session=self.session)
+        data, baseUrl = getPageContent(url, self.session)
         imageUrls = set(fetchUrls(url, data, baseUrl, self.imageSearch))
         if len(imageUrls) > 1 and not self.multipleImagesPerStrip:
             out.warn("found %d images instead of 1 with %s" % (len(imageUrls), self.imageSearch.pattern))
@@ -70,7 +70,7 @@ class _BasicScraper(object):
 
     def getComicStrip(self, url, imageUrls):
         """Get comic strip downloader for given URL and images."""
-        return ComicStrip(self.get_name(), url, imageUrls, self.namer)
+        return ComicStrip(self.get_name(), url, imageUrls, self.namer, self.session)
 
     def getAllStrips(self, maxstrips=None):
         """Get all comic strips."""
@@ -98,10 +98,17 @@ class _BasicScraper(object):
         retrieving the given number of strips."""
         seen_urls = set()
         while url:
-            data, baseUrl = getPageContent(url, session=self.session)
+            data, baseUrl = getPageContent(url, self.session)
             imageUrls = set(fetchUrls(url, data, baseUrl, self.imageSearch))
             yield self.getComicStrip(url, imageUrls)
+            prevUrl = None
+            if self.prevSearch:
+                try:
                     prevUrl = fetchUrl(url, data, baseUrl, self.prevSearch)
+                except ValueError as msg:
+                    # assume there is no previous URL, but print a warning
+                    out.warn("%s Assuming no previous comic strips exist." % msg)
+                else:
                     prevUrl = self.prevUrlModifier(prevUrl)
                     out.debug("Matched previous URL %s" % prevUrl)
             seen_urls.add(url)

dosagelib/util.py

@@ -95,16 +95,21 @@ def case_insensitive_re(name):
 
 baseSearch = re.compile(tagre("base", "href", '([^"]*)'))
 
-def getPageContent(url, max_content_bytes=MaxContentBytes, session=None):
+def getPageContent(url, session, max_content_bytes=MaxContentBytes):
     """Get text content of given URL."""
-    check_robotstxt(url)
+    check_robotstxt(url, session)
     # read page data
-    page = urlopen(url, max_content_bytes=max_content_bytes, session=session)
+    page = urlopen(url, session, max_content_bytes=max_content_bytes)
     data = page.text
-    if not data:
+    tries = 0
+    while not data and tries < 5:
         # sometimes the python requests library is wonky - try again
-        page = urlopen(url, max_content_bytes=max_content_bytes, session=session)
+        time.sleep(5)
+        page = urlopen(url, session, max_content_bytes=max_content_bytes)
         data = page.text
+        tries += 1
+    if not data:
+        raise ValueError("Got empty data from %s" % url)
     # determine base URL
     baseUrl = None
     match = baseSearch.search(data)
@@ -115,9 +120,9 @@ def getPageContent(url, max_content_bytes=MaxContentBytes, session=None):
     return data, baseUrl
 
 
-def getImageObject(url, referrer, max_content_bytes=MaxImageBytes):
+def getImageObject(url, referrer, session, max_content_bytes=MaxImageBytes):
     """Get response object for given image URL."""
-    return urlopen(url, referrer=referrer, max_content_bytes=max_content_bytes)
+    return urlopen(url, session, referrer=referrer, max_content_bytes=max_content_bytes)
 
 
 def fetchUrls(url, data, baseUrl, urlSearch):
@@ -191,21 +196,21 @@ def get_roboturl(url):
     return urlparse.urlunparse((pu[0], pu[1], "/robots.txt", "", "", ""))
 
 
-def check_robotstxt(url):
+def check_robotstxt(url, session):
     """Check if robots.txt allows our user agent for the given URL.
     @raises: IOError if URL is not allowed
     """
     roboturl = get_roboturl(url)
-    rp = get_robotstxt_parser(roboturl)
+    rp = get_robotstxt_parser(roboturl, session)
     if not rp.can_fetch(UserAgent, url):
         raise IOError("%s is disallowed by robots.txt" % url)
 
 
 @memoized
-def get_robotstxt_parser(url):
+def get_robotstxt_parser(url, session):
     """Get a RobotFileParser for the given robots.txt URL."""
     rp = robotparser.RobotFileParser()
-    req = urlopen(url, max_content_bytes=MaxContentBytes, raise_for_status=False)
+    req = urlopen(url, session, max_content_bytes=MaxContentBytes, raise_for_status=False)
     if req.status_code in (401, 403):
         rp.disallow_all = True
     elif req.status_code >= 400:
@@ -215,16 +220,14 @@ def get_robotstxt_parser(url):
     return rp
 
 
-def urlopen(url, referrer=None, max_content_bytes=None,
+def urlopen(url, session, referrer=None, max_content_bytes=None,
-            timeout=ConnectionTimeoutSecs, session=None, raise_for_status=True):
+            timeout=ConnectionTimeoutSecs, raise_for_status=True):
     """Open an URL and return the response object."""
     out.debug('Open URL %s' % url)
     headers = {'User-Agent': UserAgent}
     if referrer:
         headers['Referer'] = referrer
     out.debug('Sending headers %s' % headers, level=3)
-    if session is None:
-        session = requests
     kwargs = {
         "headers": headers,
         "timeout": timeout,