1 files changed, 76 insertions, 0 deletions
diff --git a/synapse/push/__init__.py b/synapse/push/__init__.py
new file mode 100644
index 0000000000..df0b91a8e9
--- /dev/null
+++ b/synapse/push/__init__.py
@@ -0,0 +1,76 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from twisted.internet import defer
+
+from synapse.streams.config import PaginationConfig
+from synapse.types import StreamToken
+
+import synapse.util.async
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+class Pusher(object):
+    INITIAL_BACKOFF = 1000
+    MAX_BACKOFF = 10 * 60 * 1000
+
+    def __init__(self, _hs, user_name, app, app_display_name, device_display_name, pushkey, data, last_token):
+        self.hs = _hs
+        self.evStreamHandler = self.hs.get_handlers().event_stream_handler
+        self.store = self.hs.get_datastore()
+        self.user_name = user_name
+        self.app = app
+        self.app_display_name = app_display_name
+        self.device_display_name = device_display_name
+        self.pushkey = pushkey
+        self.data = data
+        self.last_token = last_token
+        self.backoff_delay = Pusher.INITIAL_BACKOFF
+
+    @defer.inlineCallbacks
+    def start(self):
+        if not self.last_token:
+            # First-time setup: get a token to start from (we can't just start from no token, ie. 'now'
+            # because we need the result to be reproduceable in case we fail to dispatch the push)
+            config = PaginationConfig(from_token=None, limit='1')
+            chunk = yield self.evStreamHandler.get_stream(self.user_name, config, timeout=0)
+            self.last_token = chunk['end']
+            self.store.update_pusher_last_token(self.user_name, self.pushkey, self.last_token)
+            logger.info("Pusher %s for user %s starting from token %s",
+                        self.pushkey, self.user_name, self.last_token)
+
+        while True:
+            from_tok = StreamToken.from_string(self.last_token)
+            config = PaginationConfig(from_token=from_tok, limit='1')
+            chunk = yield self.evStreamHandler.get_stream(self.user_name, config, timeout=100*365*24*60*60*1000)
+
+            if (self.dispatchPush(chunk['chunk'][0])):
+                self.backoff_delay = Pusher.INITIAL_BACKOFF
+                self.last_token = chunk['end']
+                self.store.update_pusher_last_token(self.user_name, self.pushkey, self.last_token)
+            else:
+                logger.warn("Failed to dispatch push for user %s. Trying again in %dms",
+                            self.user_name, self.backoff_delay)
+                yield synapse.util.async.sleep(self.backoff_delay / 1000.0)
+                self.backoff_delay *=2
+                if self.backoff_delay > Pusher.MAX_BACKOFF:
+                    self.backoff_delay = Pusher.MAX_BACKOFF
+
+
+class PusherConfigException(Exception):
+    def __init__(self, msg):
+        super(PusherConfigException, self).__init__(msg)
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