+ LOG.warning("Updates initialised at sequence %s (%s)", seq, date)
+
+
+def check_for_updates(conn, base_url):
+ """ Check if new data is available from the replication service at the
+ given base URL.
+ """
+ _, seq, _ = status.get_status(conn)
+
+ if seq is None:
+ LOG.error("Replication not set up. "
+ "Please run 'nominatim replication --init' first.")
+ return 254
+
+ state = ReplicationServer(base_url).get_state_info()
+
+ if state is None:
+ LOG.error("Cannot get state for URL %s.", base_url)
+ return 253
+
+ if state.sequence <= seq:
+ LOG.warning("Database is up to date.")
+ return 2
+
+ LOG.warning("New data available (%i => %i).", seq, state.sequence)
+ return 0
+
+class UpdateState(Enum):
+ """ Possible states after an update has run.
+ """
+
+ UP_TO_DATE = 0
+ MORE_PENDING = 2
+ NO_CHANGES = 3
+
+
+def update(conn, options):
+ """ Update database from the next batch of data. Returns the state of
+ updates according to `UpdateState`.
+ """
+ startdate, startseq, indexed = status.get_status(conn)
+
+ if startseq is None:
+ LOG.error("Replication not set up. "
+ "Please run 'nominatim replication --init' first.")
+ raise UsageError("Replication not set up.")
+
+ if not indexed and options['indexed_only']:
+ LOG.info("Skipping update. There is data that needs indexing.")
+ return UpdateState.MORE_PENDING
+
+ last_since_update = dt.datetime.now(dt.timezone.utc) - startdate
+ update_interval = dt.timedelta(seconds=options['update_interval'])
+ if last_since_update < update_interval:
+ duration = (update_interval - last_since_update).seconds
+ LOG.warning("Sleeping for %s sec before next update.", duration)
+ time.sleep(duration)
+
+ if options['import_file'].exists():
+ options['import_file'].unlink()
+
+ # Read updates into file.
+ repl = ReplicationServer(options['base_url'])
+
+ outhandler = WriteHandler(str(options['import_file']))
+ endseq = repl.apply_diffs(outhandler, startseq + 1,
+ max_size=options['max_diff_size'] * 1024)
+ outhandler.close()
+
+ if endseq is None:
+ return UpdateState.NO_CHANGES
+
+ # Consume updates with osm2pgsql.
+ options['append'] = True
+ options['disable_jit'] = conn.server_version_tuple() >= (11, 0)
+ run_osm2pgsql(options)
+
+ # Write the current status to the file
+ endstate = repl.get_state_info(endseq)
+ status.set_status(conn, endstate.timestamp if endstate else None,
+ seq=endseq, indexed=False)
+
+ return UpdateState.UP_TO_DATE