Add store-and-forward direct-to-device messaging

synapse/storage/deviceinbox.py

@@ -0,0 +1,136 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 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.
+
+import logging
+import ujson
+
+from twisted.internet import defer
+
+from ._base import SQLBaseStore
+
+
+logger = logging.getLogger(__name__)
+
+
+class DeviceInboxStore(SQLBaseStore):
+
+    @defer.inlineCallbacks
+    def add_messages_to_device_inbox(self, messages_by_user_then_device):
+        """
+        Args:
+            messages_by_user_and_device(dict):
+                Dictionary of user_id to device_id to message.
+        Returns:
+            A deferred that resolves when the messages have been inserted.
+        """
+
+        def select_devices_txn(txn, user_id, devices):
+            if not devices:
+                return []
+            sql = (
+                "SELECT user_id, device_id FROM devices"
+                " WHERE user_id = ? AND device_id IN ("
+                + ",".join("?" * len(devices))
+                + ")"
+            )
+            # TODO: Maybe this needs to be done in batches if there are
+            # too many local devices for a given user.
+            args = [user_id] + devices
+            txn.execute(sql, args)
+            return [tuple(row) for row in txn.fetchall()]
+
+        def add_messages_to_device_inbox_txn(txn, stream_id):
+            local_users_and_devices = set()
+            for user_id, messages_by_device in messages_by_user_then_device.items():
+                local_users_and_devices.update(
+                    select_devices_txn(txn, user_id, messages_by_device.keys())
+                )
+
+            sql = (
+                "INSERT INTO device_inbox"
+                " (user_id, device_id, stream_id, message_json)"
+                " VALUES (?,?,?,?)"
+            )
+            rows = []
+            for user_id, messages_by_device in messages_by_user_then_device.items():
+                for device_id, message in messages_by_device.items():
+                    message_json = ujson.dumps(message)
+                    # Only insert into the local inbox if the device exists on
+                    # this server
+                    if (user_id, device_id) in local_users_and_devices:
+                        rows.append((user_id, device_id, stream_id, message_json))
+
+            txn.executemany(sql, rows)
+
+        with self._device_inbox_id_gen.get_next() as stream_id:
+            yield self.runInteraction(
+                "add_messages_to_device_inbox",
+                add_messages_to_device_inbox_txn,
+                stream_id
+            )
+
+    def get_new_messages_for_device(
+        self, user_id, device_id, current_stream_id, limit=100
+    ):
+        """
+        Args:
+            user_id(str): The recipient user_id.
+            device_id(str): The recipient device_id.
+            current_stream_id(int): The current position of the to device
+                message stream.
+        Returns:
+            Deferred ([dict], int): List of messages for the device and where
+                in the stream the messages got to.
+        """
+        def get_new_messages_for_device_txn(txn):
+            sql = (
+                "SELECT stream_id, message_json FROM device_inbox"
+                " WHERE user_id = ? AND device_id = ?"
+                " AND stream_id <= ?"
+                " ORDER BY stream_id ASC"
+                " LIMIT ?"
+            )
+            txn.execute(sql, (user_id, device_id, current_stream_id, limit))
+            messages = []
+            for row in txn.fetchall():
+                stream_pos = row[0]
+                messages.append(ujson.loads(row[1]))
+            if len(messages) < limit:
+                stream_pos = current_stream_id
+            return (messages, stream_pos)
+
+        return self.runInteraction(
+            "get_new_messages_for_device", get_new_messages_for_device_txn,
+        )
+
+    def delete_messages_for_device(self, user_id, device_id, up_to_stream_id):
+        """
+        Args:
+            user_id(str): The recipient user_id.
+            device_id(str): The recipient device_id.
+            up_to_stream_id(int): Where to delete messages up to.
+        Returns:
+            A deferred that resolves when the messages have been deleted.
+        """
+        def delete_messages_for_device_txn(txn):
+            sql = (
+                "DELETE FROM device_inbox"
+                " WHERE user_id = ? AND device_id = ?"
+                " AND stream_id <= ?"
+            )
+            txn.execute(sql, (user_id, device_id, up_to_stream_id))
+
+    def get_to_device_stream_token(self):
+        return self._device_inbox_id_gen.get_current_token()