Move storage classes into a main "data store".

This is in preparation for having multiple data stores that offer
different functionality, e.g. splitting out state or event storage.

synapse/storage/data_stores/main/filtering.py

@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015, 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.
+
+from canonicaljson import encode_canonical_json
+
+from synapse.api.errors import Codes, SynapseError
+from synapse.storage._base import SQLBaseStore, db_to_json
+from synapse.util.caches.descriptors import cachedInlineCallbacks
+
+
+class FilteringStore(SQLBaseStore):
+    @cachedInlineCallbacks(num_args=2)
+    def get_user_filter(self, user_localpart, filter_id):
+        # filter_id is BIGINT UNSIGNED, so if it isn't a number, fail
+        # with a coherent error message rather than 500 M_UNKNOWN.
+        try:
+            int(filter_id)
+        except ValueError:
+            raise SynapseError(400, "Invalid filter ID", Codes.INVALID_PARAM)
+
+        def_json = yield self._simple_select_one_onecol(
+            table="user_filters",
+            keyvalues={"user_id": user_localpart, "filter_id": filter_id},
+            retcol="filter_json",
+            allow_none=False,
+            desc="get_user_filter",
+        )
+
+        return db_to_json(def_json)
+
+    def add_user_filter(self, user_localpart, user_filter):
+        def_json = encode_canonical_json(user_filter)
+
+        # Need an atomic transaction to SELECT the maximal ID so far then
+        # INSERT a new one
+        def _do_txn(txn):
+            sql = (
+                "SELECT filter_id FROM user_filters "
+                "WHERE user_id = ? AND filter_json = ?"
+            )
+            txn.execute(sql, (user_localpart, bytearray(def_json)))
+            filter_id_response = txn.fetchone()
+            if filter_id_response is not None:
+                return filter_id_response[0]
+
+            sql = "SELECT MAX(filter_id) FROM user_filters " "WHERE user_id = ?"
+            txn.execute(sql, (user_localpart,))
+            max_id = txn.fetchone()[0]
+            if max_id is None:
+                filter_id = 0
+            else:
+                filter_id = max_id + 1
+
+            sql = (
+                "INSERT INTO user_filters (user_id, filter_id, filter_json)"
+                "VALUES(?, ?, ?)"
+            )
+            txn.execute(sql, (user_localpart, filter_id, bytearray(def_json)))
+
+            return filter_id
+
+        return self.runInteraction("add_user_filter", _do_txn)