Retry empty downloads and don't set a manual modification time.

doc/changelog.txt

@@ -9,6 +9,7 @@ Fixes:
 - cmdline: Catch error when piping output to another
   program or file under Windows.
   Closes: GH bug #13
+- comics: Retry download on empty content to reduce empty file errors.
 
 
 Dosage 1.12 (released 4.3.2013)

dosagelib/comic.py

@@ -1,19 +1,12 @@
 # -*- coding: iso-8859-1 -*-
 # Copyright (C) 2004-2005 Tristan Seligmann and Jonathan Jacobs
 # Copyright (C) 2012-2013 Bastian Kleineidam
-
 import os
-import rfc822
-import time
 
 from .output import out
 from .util import getImageObject, normaliseURL, unquote, strsize, getDirname, getFilename
 from .events import getHandler
 
-class FetchComicError(IOError):
-    """Exception for comic fetching errors."""
-    pass
-
 class ComicStrip(object):
     """A list of comic image URLs."""
 
@@ -59,8 +52,7 @@ class ComicImage(object):
         try:
             self.urlobj = getImageObject(self.url, self.referrer, self.session)
         except IOError as msg:
-            raise FetchComicError('Unable to retrieve URL.', self.url, msg)
+            raise IOError('error retrieving URL %s: %s' % (self.url, msg))
-
         content_type = unquote(self.urlobj.headers.get('content-type'))
         content_type = content_type.split(';', 1)[0]
         if '/' in content_type:
@@ -69,48 +61,37 @@ class ComicImage(object):
             maintype = content_type
             subtype = None
         if maintype != 'image' and content_type not in ('application/octet-stream', 'application/x-shockwave-flash'):
-            raise FetchComicError('Content type %r is not an image.' % content_type, self.url)
+            raise IOError('content type %r is not an image at %s' % (content_type, self.url))
-
         # Always use mime type for file extension if it is sane.
         if maintype == 'image':
             self.ext = '.' + subtype.replace('jpeg', 'jpg')
         self.contentLength = int(self.urlobj.headers.get('content-length', 0))
-        self.lastModified = self.urlobj.headers.get('last-modified')
         out.debug('... filename = %r, ext = %r, contentLength = %d' % (self.filename, self.ext, self.contentLength))
 
-    def touch(self, filename):
-        """Set last modified date on filename."""
-        if self.lastModified:
-            tt = rfc822.parsedate(self.lastModified)
-            if tt:
-                mtime = time.mktime(tt)
-                os.utime(filename, (mtime, mtime))
-
     def save(self, basepath):
         """Save comic URL to filename on disk."""
         out.info("Get image URL %s" % self.url, level=1)
         self.connect()
         filename = "%s%s" % (self.filename, self.ext)
-        comicSize = self.contentLength
         comicDir = os.path.join(basepath, self.dirname)
         if not os.path.isdir(comicDir):
             os.makedirs(comicDir)
-
         fn = os.path.join(comicDir, filename)
-        # compare with >= since comicSize could be the compressed size
+        # compare with >= since content length could be the compressed size
-        if os.path.isfile(fn) and os.path.getsize(fn) >= comicSize:
+        if os.path.isfile(fn) and os.path.getsize(fn) >= self.contentLength:
-            self.touch(fn)
             out.info('Skipping existing file "%s".' % fn)
             return fn, False
-
+        content = self.urlobj.content
+        if not content:
+            out.warn("Empty content from %s, try again..." % self.url)
+            self.connect()
+            content = self.urlobj.content
         try:
             out.debug('Writing comic to file %s...' % fn)
             with open(fn, 'wb') as comicOut:
-                for chunk in self.urlobj.iter_content(chunk_size=self.ChunkBytes):
+                comicOut.write(content)
-                    comicOut.write(chunk)
                 comicOut.flush()
                 os.fsync(comicOut.fileno())
-            self.touch(fn)
             size = os.path.getsize(fn)
             if size == 0:
                 raise OSError("empty file %s" % fn)
@@ -121,5 +102,4 @@ class ComicImage(object):
         else:
             out.info("Saved %s (%s)." % (fn, strsize(size)))
             getHandler().comicDownloaded(self.name, fn)
-
         return fn, True