# SPDX-License-Identifier: GPL-2.0-only # # This file is part of Nominatim. (https://nominatim.org) # # Copyright (C) 2023 by the Nominatim developer community. # For a full list of authors see the git log. """ Implementation of classes for API access via libraries. """ from typing import Mapping, Optional, Any, AsyncIterator, Dict, Sequence import asyncio import contextlib from pathlib import Path import sqlalchemy as sa import sqlalchemy.ext.asyncio as sa_asyncio import asyncpg from nominatim.db.sqlalchemy_schema import SearchTables from nominatim.config import Configuration from nominatim.api.connection import SearchConnection from nominatim.api.status import get_status, StatusResult from nominatim.api.lookup import get_detailed_place, get_simple_place from nominatim.api.reverse import ReverseGeocoder from nominatim.api.types import PlaceRef, LookupDetails, AnyPoint, DataLayer from nominatim.api.results import DetailedResult, ReverseResult, SearchResults class NominatimAPIAsync: """ API loader asynchornous version. """ def __init__(self, project_dir: Path, environ: Optional[Mapping[str, str]] = None) -> None: self.config = Configuration(project_dir, environ) self.server_version = 0 self._engine_lock = asyncio.Lock() self._engine: Optional[sa_asyncio.AsyncEngine] = None self._tables: Optional[SearchTables] = None self._property_cache: Dict[str, Any] = {'DB:server_version': 0} async def setup_database(self) -> None: """ Set up the engine and connection parameters. This function will be implicitly called when the database is accessed for the first time. You may also call it explicitly to avoid that the first call is delayed by the setup. """ async with self._engine_lock: if self._engine: return dsn = self.config.get_database_params() query = {k: v for k, v in dsn.items() if k not in ('user', 'password', 'dbname', 'host', 'port')} query['prepared_statement_cache_size'] = '0' dburl = sa.engine.URL.create( 'postgresql+asyncpg', database=dsn.get('dbname'), username=dsn.get('user'), password=dsn.get('password'), host=dsn.get('host'), port=int(dsn['port']) if 'port' in dsn else None, query=query) engine = sa_asyncio.create_async_engine( dburl, future=True, connect_args={'server_settings': { 'DateStyle': 'sql,european', 'max_parallel_workers_per_gather': '0' }}) try: async with engine.begin() as conn: result = await conn.scalar(sa.text('SHOW server_version_num')) server_version = int(result) except asyncpg.PostgresError: server_version = 0 if server_version >= 110000: @sa.event.listens_for(engine.sync_engine, "connect") def _on_connect(dbapi_con: Any, _: Any) -> None: cursor = dbapi_con.cursor() cursor.execute("SET jit_above_cost TO '-1'") # Make sure that all connections get the new settings await self.close() self._property_cache['DB:server_version'] = server_version self._tables = SearchTables(sa.MetaData(), engine.name) # pylint: disable=no-member self._engine = engine async def close(self) -> None: """ Close all active connections to the database. The NominatimAPIAsync object remains usable after closing. If a new API functions is called, new connections are created. """ if self._engine is not None: await self._engine.dispose() @contextlib.asynccontextmanager async def begin(self) -> AsyncIterator[SearchConnection]: """ Create a new connection with automatic transaction handling. This function may be used to get low-level access to the database. Refer to the documentation of SQLAlchemy for details how to use the connection object. """ if self._engine is None: await self.setup_database() assert self._engine is not None assert self._tables is not None async with self._engine.begin() as conn: yield SearchConnection(conn, self._tables, self._property_cache) async def status(self) -> StatusResult: """ Return the status of the database. """ try: async with self.begin() as conn: status = await get_status(conn) except asyncpg.PostgresError: return StatusResult(700, 'Database connection failed') return status async def details(self, place: PlaceRef, details: Optional[LookupDetails] = None) -> Optional[DetailedResult]: """ Get detailed information about a place in the database. Returns None if there is no entry under the given ID. """ async with self.begin() as conn: return await get_detailed_place(conn, place, details or LookupDetails()) async def lookup(self, places: Sequence[PlaceRef], details: Optional[LookupDetails] = None) -> SearchResults: """ Get simple information about a list of places. Returns a list of place information for all IDs that were found. """ if details is None: details = LookupDetails() async with self.begin() as conn: return SearchResults(filter(None, [await get_simple_place(conn, p, details) for p in places])) async def reverse(self, coord: AnyPoint, max_rank: Optional[int] = None, layer: Optional[DataLayer] = None, details: Optional[LookupDetails] = None) -> Optional[ReverseResult]: """ Find a place by its coordinates. Also known as reverse geocoding. Returns the closest result that can be found or None if no place matches the given criteria. """ # The following negation handles NaN correctly. Don't change. if not abs(coord[0]) <= 180 or not abs(coord[1]) <= 90: # There are no results to be expected outside valid coordinates. return None if layer is None: layer = DataLayer.ADDRESS | DataLayer.POI max_rank = max(0, min(max_rank or 30, 30)) async with self.begin() as conn: geocoder = ReverseGeocoder(conn, max_rank, layer, details or LookupDetails()) return await geocoder.lookup(coord) class NominatimAPI: """ API loader, synchronous version. """ def __init__(self, project_dir: Path, environ: Optional[Mapping[str, str]] = None) -> None: self._loop = asyncio.new_event_loop() self._async_api = NominatimAPIAsync(project_dir, environ) def close(self) -> None: """ Close all active connections to the database. The NominatimAPIAsync object remains usable after closing. If a new API functions is called, new connections are created. """ self._loop.run_until_complete(self._async_api.close()) self._loop.close() @property def config(self) -> Configuration: """ Return the configuration used by the API. """ return self._async_api.config def status(self) -> StatusResult: """ Return the status of the database. """ return self._loop.run_until_complete(self._async_api.status()) def details(self, place: PlaceRef, details: Optional[LookupDetails] = None) -> Optional[DetailedResult]: """ Get detailed information about a place in the database. """ return self._loop.run_until_complete(self._async_api.details(place, details)) def lookup(self, places: Sequence[PlaceRef], details: Optional[LookupDetails] = None) -> SearchResults: """ Get simple information about a list of places. Returns a list of place information for all IDs that were found. """ return self._loop.run_until_complete(self._async_api.lookup(places, details)) def reverse(self, coord: AnyPoint, max_rank: Optional[int] = None, layer: Optional[DataLayer] = None, details: Optional[LookupDetails] = None) -> Optional[ReverseResult]: """ Find a place by its coordinates. Also known as reverse geocoding. Returns the closest result that can be found or None if no place matches the given criteria. """ return self._loop.run_until_complete( self._async_api.reverse(coord, max_rank, layer, details))