Rework exception-handling code for current feedparser.

Errors from urllib2 used to be reported in bozo_exception. They are now
raised directly from feedparser.parse, which probably makes more sense.
rawdog now handles both cases, putting network-ish exceptions into
rawdog_exception either way; it also sets rawdog_timeout when a timeout
occurs, which should make it easier for plugins to detect this.

As a result, there's no longer a distinction between the "Error while
fetching feed" and "Error fetching or parsing feed" messages, and a
traceback can be printed for both if showtracebacks is on.

diff --git a/NEWS b/NEWS
index 5da3af2efad19a7fc7ef6860cc8e8b0c37531b33..38bb71debcb1a262c28e64ad418ce54303564b18 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -18,7 +18,16 @@ default value.
 
 Support the current development version of feedparser (which will
 presumably be the 5.3 release eventually), which has been restructured
-into multiple modules.
+into multiple modules, and raises network exceptions (e.g. timeouts)
+directly from feedparser.parse rather than putting them in
+bozo_exception.
+
+rawdog's exception-handling code has been cleaned up as a result of the
+above, and should work consistently for old and new versions of
+feedparser. In the feedparser result dict, "bozo_exception" is now
+converted to "rawdog_exception" for network errors, and "rawdog_timeout"
+is set if a timeout exception occurred. For compatibility with existing
+plugins, an empty "feed" is also provided on a timeout.
 
 - rawdog 2.22
 

diff --git a/rawdoglib/rawdog.py b/rawdoglib/rawdog.py
index 23568ab21c032ca74ab35001596e2238a2bc5e62..a781d700012f75bfaecb327ce74eaa4388f0d172 100644 (file)
--- a/rawdoglib/rawdog.py
+++ b/rawdoglib/rawdog.py
@@ -363,6 +363,12 @@ def is_timeout_exception(exc):
        """Return True if the given exception object suggests that a timeout
        occurred, else return False."""
 
+       if exc is None:
+               return False
+
+       if isinstance(exc, socket.timeout):
+               return True
+
        # Since urlopen throws away the original exception object,
        # we have to look at the stringified form to tell if it was a timeout.
        # (We're in reasonable company here, since test_ssl.py in the Python
@@ -514,12 +520,30 @@ class Feed:
 
                try:
                        result = feedparser.parse(url, **parse_args)
+
+                       # Older versions of feedparser return some kinds of
+                       # download errors in bozo_exception rather than raising
+                       # them from feedparser.parse. Normalise this.
+                       e = result.get("bozo_exception")
+                       if is_timeout_exception(e):
+                               result = {"rawdog_timeout": e}
+                       elif isinstance(e, urllib2.URLError):
+                               result = {"rawdog_exception": e}
                except Exception, e:
-                       result = {
-                               "rawdog_exception": e,
-                               "rawdog_traceback": sys.exc_info()[2],
-                               }
+                       if is_timeout_exception(e):
+                               result = {"rawdog_timeout": e}
+                       else:
+                               result = {
+                                       "rawdog_exception": e,
+                                       "rawdog_traceback": sys.exc_info()[2],
+                                       }
                result["rawdog_responses"] = logger.get_log()
+
+               # For compatibility with old hooks, include an empty "feed"
+               # if a timeout occurred.
+               if "rawdog_timeout" in result:
+                       result["feed"] = []
+
                return result
 
        def update(self, rawdog, now, config, articles, p):
@@ -551,15 +575,6 @@ class Feed:
                fatal = False
                old_url = self.url
 
-               if "rawdog_exception" in p:
-                       errors.append("Error fetching or parsing feed:")
-                       errors.append(str(p["rawdog_exception"]))
-                       if config["showtracebacks"]:
-                               from traceback import format_tb
-                               errors.append("".join(format_tb(p["rawdog_traceback"])))
-                       errors.append("")
-                       fatal = True
-
                if len(responses) != 0 and responses[0]["status"] == 301:
                        # Permanent redirect(s). Find the new location.
                        i = 0
@@ -593,23 +608,21 @@ class Feed:
                                        errors.append("You should update its entry in your config file.")
                        errors.append("")
 
-               bozo_exception = p.get("bozo_exception")
-               got_urlerror = isinstance(bozo_exception, urllib2.URLError)
-               got_timeout = isinstance(bozo_exception, socket.timeout)
-               if got_urlerror or got_timeout:
-                       # urllib2 reported an error when fetching the feed.
-                       # Check to see if it was a timeout.
-                       if not (got_timeout or is_timeout_exception(bozo_exception)):
-                               errors.append("Error while fetching feed:")
-                               errors.append(str(bozo_exception))
-                               errors.append("")
-                               fatal = True
-                       elif config["ignoretimeouts"]:
+               if "rawdog_timeout" in p:
+                       if config["ignoretimeouts"]:
                                return False
                        else:
                                errors.append("Timeout while reading feed.")
                                errors.append("")
                                fatal = True
+               elif "rawdog_exception" in p:
+                       errors.append("Error fetching or parsing feed:")
+                       errors.append(str(p["rawdog_exception"]))
+                       if config["showtracebacks"] and "rawdog_traceback" in p:
+                               from traceback import format_tb
+                               errors.append("".join(format_tb(p["rawdog_traceback"])))
+                       errors.append("")
+                       fatal = True
                elif last_status == 304:
                        # The feed hasn't changed. Return False to indicate
                        # that we shouldn't do expiry.