From 8740e4e94a6de62680db2b6c7b9f9bfda244d8ae Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 13 Jan 2016 11:37:17 +0000
Subject: [PATCH] bulk_get_push_rules should handle empty lists

---
 synapse/storage/push_rule.py | 34 +++++++++++++---------------------
 1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/synapse/storage/push_rule.py b/synapse/storage/push_rule.py
index 0829262f42..24d137f8ca 100644
--- a/synapse/storage/push_rule.py
+++ b/synapse/storage/push_rule.py
@@ -57,43 +57,35 @@ class PushRuleStore(SQLBaseStore):
 
     @defer.inlineCallbacks
     def bulk_get_push_rules(self, user_ids):
+        if not user_ids:
+            defer.returnValue({})
+
         batch_size = 100
 
         def f(txn, user_ids_to_fetch):
             sql = (
-                "SELECT " +
-                ",".join("pr."+x for x in PushRuleTable.fields) +
-                " FROM " + PushRuleTable.table_name + " pr " +
-                " LEFT JOIN " + PushRuleEnableTable.table_name + " pre " +
-                " ON pr.user_name = pre.user_name and pr.rule_id = pre.rule_id " +
-                " WHERE pr.user_name " +
+                "SELECT pr.*"
+                " FROM push_rules as pr "
+                " LEFT JOIN push_rules_enable as pre "
+                " ON pr.user_name = pre.user_name and pr.rule_id = pre.rule_id "
+                " WHERE pr.user_name "
                 " IN (" + ",".join("?" for _ in user_ids_to_fetch) + ")"
                 " AND (pre.enabled is null or pre.enabled = 1)"
                 " ORDER BY pr.user_name, pr.priority_class DESC, pr.priority DESC"
             )
             txn.execute(sql, user_ids_to_fetch)
-            return txn.fetchall()
+            return self.cursor_to_dict(txn)
 
         results = {}
 
-        batch_start = 0
-        while batch_start < len(user_ids):
-            batch_end = min(len(user_ids), batch_size)
-            batch_user_ids = user_ids[batch_start:batch_end]
-            batch_start = batch_end
-
+        chunks = [user_ids[i:i+batch_size] for i in xrange(0, len(user_ids), batch_size)]
+        for batch_user_ids in chunks:
             rows = yield self.runInteraction(
                 "bulk_get_push_rules", f, batch_user_ids
             )
 
-            for r in rows:
-                rawdict = {
-                    PushRuleTable.fields[i]: r[i] for i in range(len(r))
-                }
-
-                if rawdict['user_name'] not in results:
-                    results[rawdict['user_name']] = []
-                results[rawdict['user_name']].append(rawdict)
+            for row in rows:
+                results.setdefault(row['user_name'], []).append(row)
         defer.returnValue(results)
 
     @defer.inlineCallbacks