Add an ugly fix to avoid endless disco#info queries with each message (with receipts)

We need to check if the remote entity supports 0184, but if it doesn’t
support disco#info, then we will get an iq type="error" and nothing
will be cached, leading to disco#info queries being sent each time.

Keep a cache valid 2 hours of the JIDs which replied with an error.
TODO: check that this the kind of time period we want.

1 files changed, 90 insertions, 1 deletions

diff --git a/src/fixes.py b/src/fixes.py
index 75ac6343..cb992e88 100644
--- a/src/fixes.py
+++ b/src/fixes.py
@@ -5,12 +5,15 @@ upstream.
 TODO: Check that they are fixed and remove those hacks
 """
 
-
 from sleekxmpp.stanza import Message
 from sleekxmpp.xmlstream import ET
 
 import logging
 
+# used to avoid doing numerous useless disco#info requests
+# especially with message receipts
+IQ_ERRORS = set()
+
 log = logging.getLogger(__name__)
 
 def has_identity(xmpp, jid, identity):
@@ -96,3 +99,89 @@ def _filter_add_receipt_request(self, stanza):
 
     stanza['request_receipt'] = True
     return stanza
+
+def xep_30_supports(self, jid, node, ifrom, data):
+    """
+    Check if a JID supports a given feature.
+
+    The data parameter may provide:
+        feature  -- The feature to check for support.
+        local    -- If true, then the query is for a JID/node
+                    combination handled by this Sleek instance and
+                    no stanzas need to be sent.
+                    Otherwise, a disco stanza must be sent to the
+                    remove JID to retrieve the info.
+        cached   -- If true, then look for the disco info data from
+                    the local cache system. If no results are found,
+                    send the query as usual. The self.use_cache
+                    setting must be set to true for this option to
+                    be useful. If set to false, then the cache will
+                    be skipped, even if a result has already been
+                    cached. Defaults to false.
+    """
+    feature = data.get('feature', None)
+
+    data = {'local': data.get('local', False),
+            'cached': data.get('cached', True)}
+
+    if not feature or jid.full in IQ_ERRORS:
+        return False
+
+    try:
+        info = self.disco.get_info(jid=jid, node=node,
+                                   ifrom=ifrom, **data)
+        info = self.disco._wrap(ifrom, jid, info, True)
+        features = info['disco_info']['features']
+        return feature in features
+    except:
+        IQ_ERRORS.add(jid.full)
+        log.debug('%s added to the list of entities that do'
+                  'not honor disco#info', jid.full)
+        return False
+
+def xep_115_supports(self, jid, node, ifrom, data):
+    """
+    Check if a JID supports a given feature.
+
+    The data parameter may provide:
+        feature  -- The feature to check for support.
+        local    -- If true, then the query is for a JID/node
+                    combination handled by this Sleek instance and
+                    no stanzas need to be sent.
+                    Otherwise, a disco stanza must be sent to the
+                    remove JID to retrieve the info.
+        cached   -- If true, then look for the disco info data from
+                    the local cache system. If no results are found,
+                    send the query as usual. The self.use_cache
+                    setting must be set to true for this option to
+                    be useful. If set to false, then the cache will
+                    be skipped, even if a result has already been
+                    cached. Defaults to false.
+    """
+    feature = data.get('feature', None)
+
+    data = {'local': data.get('local', False),
+            'cached': data.get('cached', True)}
+
+    if not feature or jid.full in IQ_ERRORS:
+        return False
+
+    if node in (None, ''):
+        info = self.caps.get_caps(jid)
+        if info and feature in info['features']:
+            return True
+
+    try:
+        info = self.disco.get_info(jid=jid, node=node,
+                                   ifrom=ifrom, **data)
+        info = self.disco._wrap(ifrom, jid, info, True)
+        return feature in info['disco_info']['features']
+    except:
+        IQ_ERRORS.add(jid.full)
+        log.debug('%s added to the list of entities that do'
+                  'not honor disco#info', jid.full)
+        return False
+
+def reset_iq_errors():
+    "reset the iq error cache"
+    IQ_ERRORS.clear()