+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
"""
Functions for updating a database from a replication source.
"""
-import datetime
+from typing import ContextManager, MutableMapping, Any, Generator, cast, Iterator
+from contextlib import contextmanager
+import datetime as dt
+from enum import Enum
import logging
+import time
+import types
+import urllib.request as urlrequest
-from osmium.replication.server import ReplicationServer
+import requests
+from nominatim.db import status
+from nominatim.db.connection import Connection, connect
+from nominatim.tools.exec_utils import run_osm2pgsql
+from nominatim.errors import UsageError
-from ..db import status
+try:
+ from osmium.replication.server import ReplicationServer
+ from osmium import WriteHandler
+ from osmium import version as pyo_version
+except ImportError as exc:
+ logging.getLogger().critical("pyosmium not installed. Replication functions not available.\n"
+ "To install pyosmium via pip: pip3 install osmium")
+ raise UsageError("replication tools not available") from exc
LOG = logging.getLogger()
-def init_replication(conn, base_url):
+def init_replication(conn: Connection, base_url: str,
+ socket_timeout: int = 60) -> None:
""" Set up replication for the server at the given base URL.
"""
LOG.info("Using replication source: %s", base_url)
date = status.compute_database_date(conn)
# margin of error to make sure we get all data
- date -= datetime.timedelta(hours=3)
+ date -= dt.timedelta(hours=3)
- repl = ReplicationServer(base_url)
-
- seq = repl.timestamp_to_sequence(date)
+ with _make_replication_server(base_url, socket_timeout) as repl:
+ seq = repl.timestamp_to_sequence(date)
if seq is None:
LOG.fatal("Cannot reach the configured replication service '%s'.\n"
"Does the URL point to a directory containing OSM update data?",
base_url)
- raise RuntimeError("Failed to reach replication service")
+ raise UsageError("Failed to reach replication service")
status.set_status(conn, date=date, seq=seq)
- LOG.warning("Updates intialised at sequence %s (%s)", seq, date)
+ LOG.warning("Updates initialised at sequence %s (%s)", seq, date)
+
+
+def check_for_updates(conn: Connection, base_url: str,
+ socket_timeout: int = 60) -> int:
+ """ 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
+
+ with _make_replication_server(base_url, socket_timeout) as repl:
+ state = repl.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(dsn: str, 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`.
+ """
+ with connect(dsn) as conn:
+ startdate, startseq, indexed = status.get_status(conn)
+ conn.commit()
+
+ 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
+
+ with connect(dsn) as conn:
+ 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)
+ conn.commit()
+
+ 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()