Implement _simple_delete_many_txn, use it to delete devices

(But this doesn't implement the same for deleting access tokens or e2e keys.

Also respond to code review.

4 files changed, 101 insertions, 11 deletions

diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index e859b3165f..efaa0c8d6e 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -170,6 +170,40 @@ class DeviceHandler(BaseHandler):
         yield self.notify_device_update(user_id, [device_id])
 
     @defer.inlineCallbacks
+    def delete_devices(self, user_id, device_ids):
+        """ Delete several devices
+
+        Args:
+            user_id (str):
+            device_ids (str): The list of device IDs to delete
+
+        Returns:
+            defer.Deferred:
+        """
+
+        try:
+            yield self.store.delete_devices(user_id, device_ids)
+        except errors.StoreError, e:
+            if e.code == 404:
+                # no match
+                pass
+            else:
+                raise
+
+        # Delete access tokens and e2e keys for each device. Not optimised as it is not
+        # considered as part of a critical path.
+        for device_id in device_ids:
+            yield self.store.user_delete_access_tokens(
+                user_id, device_id=device_id,
+                delete_refresh_tokens=True,
+            )
+            yield self.store.delete_e2e_keys_by_device(
+                user_id=user_id, device_id=device_id
+            )
+
+        yield self.notify_device_update(user_id, device_ids)
+
+    @defer.inlineCallbacks
     def update_device(self, user_id, device_id, content):
         """ Update the given device
 
diff --git a/synapse/rest/client/v2_alpha/devices.py b/synapse/rest/client/v2_alpha/devices.py
index fd9516a601..b57ba95d24 100644
--- a/synapse/rest/client/v2_alpha/devices.py
+++ b/synapse/rest/client/v2_alpha/devices.py
@@ -47,13 +47,13 @@ class DevicesRestServlet(servlet.RestServlet):
 
 
 class DeleteDevicesRestServlet(servlet.RestServlet):
+    """
+    API for bulk deletion of devices. Accepts a JSON object with a devices
+    key which lists the device_ids to delete. Requires user interactive auth.
+    """
     PATTERNS = client_v2_patterns("/delete_devices", releases=[], v2_alpha=False)
 
     def __init__(self, hs):
-        """
-        Args:
-            hs (synapse.server.HomeServer): server
-        """
         super(DeleteDevicesRestServlet, self).__init__()
         self.hs = hs
         self.auth = hs.get_auth()
@@ -64,14 +64,13 @@ class DeleteDevicesRestServlet(servlet.RestServlet):
     def on_POST(self, request):
         try:
             body = servlet.parse_json_object_from_request(request)
-
         except errors.SynapseError as e:
             if e.errcode == errors.Codes.NOT_JSON:
                 # deal with older clients which didn't pass a J*DELETESON dict
                 # the same as those that pass an empty dict
                 body = {}
             else:
-                raise
+                raise e
 
         if 'devices' not in body:
             raise errors.SynapseError(
@@ -86,11 +85,10 @@ class DeleteDevicesRestServlet(servlet.RestServlet):
             defer.returnValue((401, result))
 
         requester = yield self.auth.get_user_by_req(request)
-        for d_id in body['devices']:
-            yield self.device_handler.delete_device(
-                requester.user.to_string(),
-                d_id,
-            )
+        yield self.device_handler.delete_devices(
+            requester.user.to_string(),
+            body['devices'],
+        )
         defer.returnValue((200, {}))
 
 
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index a7a8ec9b7b..13b106bba1 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -840,6 +840,47 @@ class SQLBaseStore(object):
 
         return txn.execute(sql, keyvalues.values())
 
+    def _simple_delete_many(self, table, column, iterable, keyvalues, desc):
+        return self.runInteraction(
+            desc, self._simple_delete_many_txn, table, column, iterable, keyvalues
+        )
+
+    @staticmethod
+    def _simple_delete_many_txn(txn, table, column, iterable, keyvalues):
+        """Executes a DELETE query on the named table.
+
+        Filters rows by if value of `column` is in `iterable`.
+
+        Args:
+            txn : Transaction object
+            table : string giving the table name
+            column : column name to test for inclusion against `iterable`
+            iterable : list
+            keyvalues : dict of column names and values to select the rows with
+        """
+        if not iterable:
+            return
+
+        sql = "DELETE FROM %s" % table
+
+        clauses = []
+        values = []
+        clauses.append(
+            "%s IN (%s)" % (column, ",".join("?" for _ in iterable))
+        )
+        values.extend(iterable)
+
+        for key, value in keyvalues.items():
+            clauses.append("%s = ?" % (key,))
+            values.append(value)
+
+        if clauses:
+            sql = "%s WHERE %s" % (
+                sql,
+                " AND ".join(clauses),
+            )
+        return txn.execute(sql, values)
+
     def _get_cache_dict(self, db_conn, table, entity_column, stream_column,
                         max_value, limit=100000):
         # Fetch a mapping of room_id -> max stream position for "recent" rooms.
diff --git a/synapse/storage/devices.py b/synapse/storage/devices.py
index bd56ba2515..563071b7a9 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/devices.py
@@ -108,6 +108,23 @@ class DeviceStore(SQLBaseStore):
             desc="delete_device",
         )
 
+    def delete_devices(self, user_id, device_ids):
+        """Deletes several devices.
+
+        Args:
+            user_id (str): The ID of the user which owns the devices
+            device_ids (list): The IDs of the devices to delete
+        Returns:
+            defer.Deferred
+        """
+        return self._simple_delete_many(
+            table="devices",
+            column="device_id",
+            iterable=device_ids,
+            keyvalues={"user_id": user_id},
+            desc="delete_devices",
+        )
+
     def update_device(self, user_id, device_id, new_display_name=None):
         """Update a device.