Only download feeds that have changed (or that don't give us enough data to

[rss2maildir.git] / rss2maildir.py

diff --git a/rss2maildir.py b/rss2maildir.py
index 931de3ae5307bbae1fe860dbc3bff739c8cfb783..4402c43884ae5271a201de8529ebc46271a5fcdc 100755 (executable)
--- a/rss2maildir.py
+++ b/rss2maildir.py
@@ -20,6 +20,7 @@
 import sys
 import os
 import stat
+import httplib
 import urllib
 
 import feedparser
@@ -57,7 +58,7 @@ entities = {
     }
 
 class HTML2Text(HTMLParser):
-    
+
     def __init__(self):
         self.inheadingone = False
         self.inheadingtwo = False
@@ -88,23 +89,7 @@ class HTML2Text(HTMLParser):
         elif tag.lower() == "a":
             self.inlink = True
         elif tag.lower() == "br":
-            if self.inparagraph:
-                self.text = self.text \
-                    + u'\n'.join( \
-                        textwrap.wrap(self.currentparagraph, 70)) \
-                    + u'\n'
-                self.currentparagraph = ""
-            elif self.inblockquote:
-                self.text = self.text \
-                    + u'\n> ' \
-                    + u'\n> '.join( \
-                        [a.strip() \
-                            for a in textwrap.wrap(self.blockquote, 68) \
-                        ]) \
-                    + u'\n'
-                self.blockquote = u''
-            else:
-                self.text = self.text + u'\n'
+            self.handle_br()
         elif tag.lower() == "blockquote":
             self.inblockquote = True
             self.text = self.text + u'\n'
@@ -139,6 +124,9 @@ class HTML2Text(HTMLParser):
 
     def handle_startendtag(self, tag, attrs):
         if tag.lower() == "br":
+            self.handle_br()
+
+    def handle_br(self):
             if self.inparagraph:
                 self.text = self.text \
                 + u'\n'.join( \
@@ -265,7 +253,57 @@ class HTML2Text(HTMLParser):
         return data
 
 def parse_and_deliver(maildir, url, statedir):
-    fp = feedparser.parse(url)
+    feedhandle = None
+    headers = None
+    # first check if we know about this feed already
+    feeddb = dbm.open(os.path.join(statedir, "feeds"), "c")
+    # we need all the parts of the url 
+    (type, rest) = urllib.splittype(url)
+    (host, path) = urllib.splithost(rest)
+    (host, port) = urllib.splitport(host)
+    if port == None:
+        port = 80
+    if feeddb.has_key(url):
+        data = feeddb[url]
+        data = cgi.parse_qs(data)
+        # now do a head on the feed to see if it's been updated
+        conn = httplib.HTTPConnection("%s:%s" %(host, port))
+        conn.request("HEAD", path)
+        response = conn.getresponse()
+        headers = response.getheaders()
+        ischanged = False
+        try:
+            for header in headers:
+                if header[0] == "content-length":
+                    if header[1] != data["content-length"][0]:
+                        ischanged = True
+                elif header[0] == "etag":
+                    if header[1] != data["etag"][0]:
+                        ischanged = True
+                elif header[0] == "last-modified":
+                    if header[1] != data["last-modified"][0]:
+                        ischanged = True
+                elif header[0] == "content-md5":
+                    if header[1] != data["content-md5"][0]:
+                        ischanged = True
+        except:
+            ischanged = True
+        if ischanged:
+            conn = httplib.HTTPConnection("%s:%s" %(host, port))
+            conn.request("GET", path)
+            response = conn.getresponse()
+            headers = response.getheaders()
+            feedhandle = response
+        else:
+            return # don't need to do anything, nothings changed.
+    else:
+        conn = httplib.HTTPConnection("%s:%s" %(host, port))
+        conn.request("GET", path)
+        response = conn.getresponse()
+        headers = response.getheaders()
+        feedhandle = response
+
+    fp = feedparser.parse(feedhandle)
     db = dbm.open(os.path.join(statedir, "seen"), "c")
     for item in fp["items"]:
         # have we seen it before?
@@ -352,7 +390,17 @@ def parse_and_deliver(maildir, url, statedir):
             ))
         db[url + "|" + item["link"]] = data
 
+    if headers:
+        data = []
+        for header in headers:
+            if header[0] in ["content-md5", "etag", "last-modified", "content-length"]:
+                data.append((header[0], header[1]))
+        if len(data) > 0:
+            data = urllib.urlencode(data)
+            feeddb[url] = data
+
     db.close()
+    feeddb.close()
 
 # first off, parse the command line arguments