Add a bulk user info endpoint and deprecate the old one (#46)

The current `/user/<user_id>/info` API was useful in that it could be used by any user to lookup whether another user was deactivate or expired. However, it was impractical as it only allowed for a single lookup at once. Clients trying to use this API were met with speed issues as they tried to query this information for all users in a room.

This PR adds an equivalent CS and Federation API that takes a list of user IDs, and returning a mapping from user ID to info dictionary.

Note that the federation in this PR was a bit trickier than in the original #12 as we can no longer use a federation query, as those don't allow for JSON bodies - which we require to pass a list of user IDs. Instead we do the whole thing of adding a method to transport/client and transport/server.

This PR also adds unittests. The earlier PR used Sytest, presumably for testing across federation, but as this is Synapse-specific that felt a little gross. Unit tests for the deprecated endpoint have not been added.

1 files changed, 50 insertions, 0 deletions

diff --git a/synapse/storage/data_stores/main/registration.py b/synapse/storage/data_stores/main/registration.py

index b07c44d87a..1f1a7b4e36 100644
--- a/synapse/storage/data_stores/main/registration.py
+++ b/synapse/storage/data_stores/main/registration.py
@@ -17,6 +17,7 @@
 
 import logging
 import re
+from typing import List
 
 from six import iterkeys
 
@@ -304,6 +305,55 @@ class RegistrationWorkerStore(SQLBaseStore):
             desc="delete_account_validity_for_user",
         )
 
+    @defer.inlineCallbacks
+    def get_info_for_users(
+        self, user_ids: List[str],
+    ):
+        """Return the user info for a given set of users
+
+        Args:
+            user_ids: A list of users to return information about
+
+        Returns:
+            Deferred[Dict[str, bool]]: A dictionary mapping each user ID to
+                a dict with the following keys:
+                    * expired - whether this is an expired user
+                    * deactivated - whether this is a deactivated user
+        """
+        # Get information of all our local users
+        def _get_info_for_users_txn(txn):
+            rows = []
+
+            for user_id in user_ids:
+                sql = """
+                    SELECT u.name, u.deactivated, av.expiration_ts_ms
+                    FROM users as u
+                    LEFT JOIN account_validity as av
+                    ON av.user_id = u.name
+                    WHERE u.name = ?
+                """
+
+                txn.execute(sql, (user_id,))
+                row = txn.fetchone()
+                if row:
+                    rows.append(row)
+
+            return rows
+
+        info_rows = yield self.db.runInteraction(
+            "get_info_for_users", _get_info_for_users_txn
+        )
+
+        return {
+            user_id: {
+                "expired": (
+                    expiration is not None and self.clock.time_msec() >= expiration
+                ),
+                "deactivated": deactivated == 1,
+            }
+            for user_id, deactivated, expiration in info_rows
+        }
+
     async def is_server_admin(self, user):
         """Determines if a user is an admin of this homeserver.