Ticket #11565: error_email_rate_limit_v2.diff

core/handlers/base.py

@@ +1 @@
+try:
+    from hashlib import md5
+except ImportError:
+    from md5 import md5
 import sys
+from datetime import datetime, timedelta
 
+from django.core.cache import cache                               
 from django import http
 from django.core import signals
 from django.utils.encoding import force_unicode
@@ -13 +19 @@
         http.fix_IE_for_attach,
         http.fix_IE_for_vary,
     ]
+    
+    _errors = {}
 
     def __init__(self):
         self._request_middleware = self._view_middleware = self._response_middleware = self._exception_middleware = None
@@ -166 +174 @@
             return debug.technical_500_response(request, *exc_info)
 
         # When DEBUG is False, send an error message to the admins.
-        subject = 'Error (%s IP): %s' % ((request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS and 'internal' or 'EXTERNAL'), request.path)
-        try:
-            request_repr = repr(request)
-        except:
-            request_repr = "Request repr() unavailable"
-        message = "%s\n\n%s" % (self._get_traceback(exc_info), request_repr)
-        mail_admins(subject, message, fail_silently=True)
+        
+        # Where settings.ERROR_EMAIL_RATE_LIMIT > 0, limit to one duplicate 
+        # email per ERROR_EMAIL_RATE_LIMIT seconds. Use cache if available, 
+        # otherwise use local memory, limited to ERROR_EMAIL_KEY_LIMIT.
+        # If using cache, prefix keys with ERROR_EMAIL_CACHE_PREFIX.
+        
+        # Note: none of the above settings are required!
+        
+        tb = self._get_traceback(exc_info)
+        
+        # Track duplicate errors
+        duplicate = False
+        rate = getattr(settings, 'ERROR_EMAIL_RATE_LIMIT', 0)  # seconds
+        if rate > 0:
+            key = md5(tb).hexdigest()
+            prefix = getattr(settings, 'ERROR_EMAIL_CACHE_PREFIX', 'ERROR_EMAIL')
+            # Test the cache works
+            cache_key = '%s_%s' % (prefix, key)
+            try:
+                cache.set(prefix, 1, 1)
+                use_cache = cache.get(prefix) == 1
+            except:
+                use_cache = False
+            if use_cache:
+                duplicate = cache.get(cache_key) == 1
+                cache.set(cache_key, 1, rate)
+            else:
+                min_date = datetime.now() - timedelta(seconds=rate)
+                max_keys = getattr(settings, 'ERROR_EMAIL_KEY_LIMIT', 100)
+                duplicate = (key in self._errors and self._errors[key] >= min_date)
+                self._errors = dict(filter(lambda x: x[1] >= min_date, 
+                                          sorted(self._errors.items(), 
+                                                 key=lambda x: x[1]))[0-max_keys:])
+                if not duplicate:
+                    self._errors[key] = datetime.now()
+                    
+        # Send the error
+        if rate == 0 or not duplicate:
+            subject = 'Error (%s IP): %s' % ((request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS and 'internal' or 'EXTERNAL'), request.path)
+            try:
+                request_repr = repr(request)
+            except:
+                request_repr = "Request repr() unavailable"
+            message = "%s\n\n%s" % (tb, request_repr)
+            mail_admins(subject, message, fail_silently=True)
+
         # If Http500 handler is not installed, re-raise last exception
         if resolver.urlconf_module is None:
             raise exc_info[1], None, exc_info[2]