1 files changed, 45 insertions, 20 deletions
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index f210d26629..a89770ed7b 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -43,6 +43,22 @@ import re
 logger = logging.getLogger(__name__)
 
 
+SCHEMAS = [
+    "transactions",
+    "pdu",
+    "users",
+    "profiles",
+    "presence",
+    "im",
+    "room_aliases",
+]
+
+
+# Remember to update this number every time an incompatible change is made to
+# database schema files, so the users will be informed on server restarts.
+SCHEMA_VERSION = 1
+
+
 class SynapseHomeServer(HomeServer):
 
     def build_http_client(self):
@@ -65,31 +81,39 @@ class SynapseHomeServer(HomeServer):
         don't have to worry about overwriting existing content.
         """
         logging.info("Preparing database: %s...", self.db_name)
-        pool = adbapi.ConnectionPool(
-            'sqlite3', self.db_name, check_same_thread=False,
-            cp_min=1, cp_max=1)
 
-        schemas = [
-            "transactions",
-            "pdu",
-            "users",
-            "profiles",
-            "presence",
-            "im",
-            "room_aliases",
-        ]
+        with sqlite3.connect(self.db_name) as db_conn:
+            c = db_conn.cursor()
+            c.execute("PRAGMA user_version")
+            row = c.fetchone()
 
-        for sql_loc in schemas:
-            sql_script = read_schema(sql_loc)
+            if row and row[0]:
+                user_version = row[0]
 
-            with sqlite3.connect(self.db_name) as db_conn:
-                c = db_conn.cursor()
-                c.executescript(sql_script)
-                c.close()
-                db_conn.commit()
+                if user_version < SCHEMA_VERSION:
+                    # TODO(paul): add some kind of intelligent fixup here
+                    raise ValueError("Cannot use this database as the " +
+                        "schema version (%d) does not match (%d)" %
+                        (user_version, SCHEMA_VERSION)
+                    )
+
+            else:
+                for sql_loc in SCHEMAS:
+                    sql_script = read_schema(sql_loc)
+
+                    c.executescript(sql_script)
+                    db_conn.commit()
+
+                c.execute("PRAGMA user_version = %d" % SCHEMA_VERSION)
+
+            c.close()
 
         logging.info("Database prepared in %s.", self.db_name)
 
+        pool = adbapi.ConnectionPool(
+            'sqlite3', self.db_name, check_same_thread=False,
+            cp_min=1, cp_max=1)
+
         return pool
 
     def create_resource_tree(self, web_client, redirect_root_to_web_client):
@@ -184,6 +208,7 @@ class SynapseHomeServer(HomeServer):
 
     def start_listening(self, port):
         reactor.listenTCP(port, Site(self.root_resource))
+        logger.info("Synapse now listening on port %d", port)
 
 
 def setup_logging(verbosity=0, filename=None, config_path=None):
@@ -282,7 +307,7 @@ def setup():
         redirect_root_to_web_client=True)
     hs.start_listening(args.port)
 
-    hs.build_db_pool()
+    hs.get_db_pool()
 
     if args.manhole:
         f = twisted.manhole.telnet.ShellFactory()