Tidy up get_pusher functions

Decodes pushers rows on the main thread rather than the db thread and uses _simple_select_list. Also do the same to the function I copied and factor out the duplication into a helper function.

synapse/storage/pusher.py

@@ -56,43 +56,41 @@ class PusherStore(SQLBaseStore):
         )
         defer.returnValue(ret is not None)
 
-    @defer.inlineCallbacks
     def get_pushers_by_app_id_and_pushkey(self, app_id, pushkey):
-        def r(txn):
+        return self.get_pushers_by({
-            sql = (
+            "app_id": app_id,
-                "SELECT * FROM pushers"
+            "pushkey": pushkey,
-                " WHERE app_id = ? AND pushkey = ?"
+        })
-            )
 
-            txn.execute(sql, (app_id, pushkey,))
+    def get_pushers_by_user_id(self, user_id):
-            rows = self.cursor_to_dict(txn)
+        return self.get_pushers_by({
-
+            "user_name": user_id,
-            return self._decode_pushers_rows(rows)
+        })
-
-        rows = yield self.runInteraction(
-            "get_pushers_by_app_id_and_pushkey", r
-        )
-
-        defer.returnValue(rows)
 
     @defer.inlineCallbacks
-    def get_pushers_by_user_id(self, user_id):
+    def get_pushers_by(self, keyvalues):
-        def r(txn):
+        ret = yield self._simple_select_list(
-            sql = (
+            "pushers", keyvalues,
-                "SELECT * FROM pushers"
+            [
-                " WHERE user_name = ?"
+                "id",
+                "user_name",
+                "access_token",
+                "profile_tag",
+                "kind",
+                "app_id",
+                "app_display_name",
+                "device_display_name",
+                "pushkey",
+                "ts",
+                "lang",
+                "data",
+                "last_stream_ordering",
+                "last_success",
+                "failing_since",
+
+            ]
         )
-
+        defer.returnValue(self._decode_pushers_rows(ret))
-            txn.execute(sql, (user_id,))
-            rows = self.cursor_to_dict(txn)
-
-            return self._decode_pushers_rows(rows)
-
-        result = yield self.runInteraction(
-            "get_pushers_by_user_id", r
-        )
-
-        defer.returnValue(result)
 
     @defer.inlineCallbacks
     def get_all_pushers(self):