+
+class UpdateState(Enum):
+ """ Possible states after an update has run.
+ """
+
+ UP_TO_DATE = 0
+ MORE_PENDING = 2
+ NO_CHANGES = 3
+
+
+def update(conn: Connection, options: MutableMapping[str, Any],
+ socket_timeout: int = 60) -> UpdateState:
+ """ 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.")
+
+ assert startdate is not None
+
+ 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.
+ with _make_replication_server(options['base_url'], socket_timeout) as repl:
+ 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
+
+ run_osm2pgsql_updates(conn, 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
+
+
+def run_osm2pgsql_updates(conn: Connection, options: MutableMapping[str, Any]) -> None:
+ """ Run osm2pgsql in append mode.
+ """
+ # Remove any stale deletion marks.
+ with conn.cursor() as cur:
+ cur.execute('TRUNCATE place_to_be_deleted')
+ conn.commit()
+
+ # Consume updates with osm2pgsql.
+ options['append'] = True
+ options['disable_jit'] = conn.server_version_tuple() >= (11, 0)
+ run_osm2pgsql(options)
+
+ # Handle deletions
+ with conn.cursor() as cur:
+ cur.execute('SELECT flush_deleted_places()')
+ conn.commit()
+
+
+def _make_replication_server(url: str, timeout: int) -> ContextManager[ReplicationServer]:
+ """ Returns a ReplicationServer in form of a context manager.
+
+ Creates a light wrapper around older versions of pyosmium that did
+ not support the context manager interface.
+ """
+ if hasattr(ReplicationServer, '__enter__'):
+ # Patches the open_url function for pyosmium >= 3.2
+ # where the socket timeout is no longer respected.
+ def patched_open_url(self: ReplicationServer, url: urlrequest.Request) -> Any:
+ """ Download a resource from the given URL and return a byte sequence
+ of the content.
+ """
+ headers = {"User-Agent" : f"Nominatim (pyosmium/{pyo_version.pyosmium_release})"}
+
+ if self.session is not None:
+ return self.session.get(url.get_full_url(),
+ headers=headers, timeout=timeout or None,
+ stream=True)
+
+ @contextmanager
+ def _get_url_with_session() -> Iterator[requests.Response]:
+ with requests.Session() as session:
+ request = session.get(url.get_full_url(),
+ headers=headers, timeout=timeout or None,
+ stream=True)
+ yield request
+
+ return _get_url_with_session()
+
+ repl = ReplicationServer(url)
+ setattr(repl, 'open_url', types.MethodType(patched_open_url, repl))
+
+ return cast(ContextManager[ReplicationServer], repl)
+
+ @contextmanager
+ def get_cm() -> Generator[ReplicationServer, None, None]:
+ yield ReplicationServer(url)
+
+ return get_cm()