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Nominatim/src/nominatim_api/search/db_searches/place_search.py
2025-07-07 12:03:56 +02:00

215 lines
9.0 KiB
Python

# SPDX-License-Identifier: GPL-3.0-or-later
#
# This file is part of Nominatim. (https://nominatim.org)
#
# Copyright (C) 2025 by the Nominatim developer community.
# For a full list of authors see the git log.
"""
Implementation of search for a named place (without housenumber).
"""
from typing import cast
import sqlalchemy as sa
from . import base
from ...typing import SaBind, SaExpression, SaColumn
from ...types import SearchDetails, Bbox
from ...sql.sqlalchemy_types import Geometry
from ...connection import SearchConnection
from ... import results as nres
from ..db_search_fields import SearchData
LIMIT_PARAM: SaBind = sa.bindparam('limit')
MIN_RANK_PARAM: SaBind = sa.bindparam('min_rank')
MAX_RANK_PARAM: SaBind = sa.bindparam('max_rank')
VIEWBOX_PARAM: SaBind = sa.bindparam('viewbox', type_=Geometry)
VIEWBOX2_PARAM: SaBind = sa.bindparam('viewbox2', type_=Geometry)
NEAR_PARAM: SaBind = sa.bindparam('near', type_=Geometry)
NEAR_RADIUS_PARAM: SaBind = sa.bindparam('near_radius')
COUNTRIES_PARAM: SaBind = sa.bindparam('countries')
class PlaceSearch(base.AbstractSearch):
""" Generic search for a named place.
"""
SEARCH_PRIO = 1
def __init__(self, extra_penalty: float, sdata: SearchData,
expected_count: int, has_address_terms: bool) -> None:
assert not sdata.housenumbers
super().__init__(sdata.penalty + extra_penalty)
self.countries = sdata.countries
self.postcodes = sdata.postcodes
self.qualifiers = sdata.qualifiers
self.lookups = sdata.lookups
self.rankings = sdata.rankings
self.expected_count = expected_count
self.has_address_terms = has_address_terms
def _inner_search_name_cte(self, conn: SearchConnection,
details: SearchDetails) -> 'sa.CTE':
""" Create a subquery that preselects the rows in the search_name
table.
"""
t = conn.t.search_name
penalty: SaExpression = sa.literal(self.penalty)
for ranking in self.rankings:
penalty += ranking.sql_penalty(t)
sql = sa.select(t.c.place_id, t.c.search_rank, t.c.address_rank,
t.c.country_code, t.c.centroid,
t.c.name_vector, t.c.nameaddress_vector,
sa.case((t.c.importance > 0, t.c.importance),
else_=0.40001-(sa.cast(t.c.search_rank, sa.Float())/75))
.label('importance'),
penalty.label('penalty'))
for lookup in self.lookups:
sql = sql.where(lookup.sql_condition(t))
if self.countries:
sql = sql.where(t.c.country_code.in_(self.countries.values))
if self.postcodes:
# if a postcode is given, don't search for state or country level objects
sql = sql.where(t.c.address_rank > 9)
if self.expected_count > 10000:
# Many results expected. Restrict by postcode.
tpc = conn.t.postcode
sql = sql.where(sa.select(tpc.c.postcode)
.where(tpc.c.postcode.in_(self.postcodes.values))
.where(t.c.centroid.within_distance(tpc.c.geometry, 0.4))
.exists())
if details.viewbox is not None:
if details.bounded_viewbox:
sql = sql.where(t.c.centroid
.intersects(VIEWBOX_PARAM,
use_index=details.viewbox.area < 0.2))
elif not self.postcodes and self.expected_count >= 10000:
sql = sql.where(t.c.centroid
.intersects(VIEWBOX2_PARAM,
use_index=details.viewbox.area < 0.5))
if details.near is not None and details.near_radius is not None:
if details.near_radius < 0.1:
sql = sql.where(t.c.centroid.within_distance(NEAR_PARAM,
NEAR_RADIUS_PARAM))
else:
sql = sql.where(t.c.centroid
.ST_Distance(NEAR_PARAM) < NEAR_RADIUS_PARAM)
if details.excluded:
sql = sql.where(base.exclude_places(t))
if details.min_rank > 0:
sql = sql.where(sa.or_(t.c.address_rank >= MIN_RANK_PARAM,
t.c.search_rank >= MIN_RANK_PARAM))
if details.max_rank < 30:
sql = sql.where(sa.or_(t.c.address_rank <= MAX_RANK_PARAM,
t.c.search_rank <= MAX_RANK_PARAM))
inner = sql.limit(5000 if self.qualifiers else 1000)\
.order_by(sa.desc(sa.text('importance')))\
.subquery()
sql = sa.select(inner.c.place_id, inner.c.search_rank, inner.c.address_rank,
inner.c.country_code, inner.c.centroid, inner.c.importance,
inner.c.penalty)
# If the query is not an address search or has a geographic preference,
# preselect most important items to restrict the number of places
# that need to be looked up in placex.
if (details.viewbox is None or details.bounded_viewbox)\
and (details.near is None or details.near_radius is not None)\
and not self.qualifiers:
sql = sql.add_columns(sa.func.first_value(inner.c.penalty - inner.c.importance)
.over(order_by=inner.c.penalty - inner.c.importance)
.label('min_penalty'))
inner = sql.subquery()
sql = sa.select(inner.c.place_id, inner.c.search_rank, inner.c.address_rank,
inner.c.country_code, inner.c.centroid, inner.c.importance,
inner.c.penalty)\
.where(inner.c.penalty - inner.c.importance < inner.c.min_penalty + 0.5)
return sql.cte('searches')
async def lookup(self, conn: SearchConnection,
details: SearchDetails) -> nres.SearchResults:
""" Find results for the search in the database.
"""
t = conn.t.placex
tsearch = self._inner_search_name_cte(conn, details)
sql = base.select_placex(t).join(tsearch, t.c.place_id == tsearch.c.place_id)
if details.geometry_output:
sql = base.add_geometry_columns(sql, t.c.geometry, details)
penalty: SaExpression = tsearch.c.penalty
if self.postcodes:
if self.has_address_terms:
tpc = conn.t.postcode
pcs = self.postcodes.values
pc_near = sa.select(sa.func.min(tpc.c.geometry.ST_Distance(t.c.centroid)))\
.where(tpc.c.postcode.in_(pcs))\
.scalar_subquery()
penalty += sa.case((t.c.postcode.in_(pcs), 0.0),
else_=sa.func.coalesce(pc_near, cast(SaColumn, 2.0)))
else:
# High penalty if the postcode is not an exact match.
# The postcode search needs to get priority here.
penalty += sa.case((t.c.postcode.in_(self.postcodes.values), 0.0), else_=1.0)
if details.viewbox is not None and not details.bounded_viewbox:
penalty += sa.case((t.c.geometry.intersects(VIEWBOX_PARAM, use_index=False), 0.0),
(t.c.geometry.intersects(VIEWBOX2_PARAM, use_index=False), 0.5),
else_=1.0)
if details.near is not None:
sql = sql.add_columns((-tsearch.c.centroid.ST_Distance(NEAR_PARAM))
.label('importance'))
sql = sql.order_by(sa.desc(sa.text('importance')))
else:
sql = sql.order_by(penalty - tsearch.c.importance)
sql = sql.add_columns(tsearch.c.importance)
sql = sql.add_columns(penalty.label('accuracy'))\
.order_by(sa.text('accuracy'))
sql = sql.where(t.c.linked_place_id == None)\
.where(t.c.indexed_status == 0)
if self.qualifiers:
sql = sql.where(self.qualifiers.sql_restrict(t))
if details.layers is not None:
sql = sql.where(base.filter_by_layer(t, details.layers))
sql = sql.limit(LIMIT_PARAM)
bind_params = {
'limit': details.max_results,
'min_rank': details.min_rank,
'max_rank': details.max_rank,
'viewbox': details.viewbox,
'viewbox2': details.viewbox_x2,
'near': details.near,
'near_radius': details.near_radius,
'excluded': details.excluded,
'countries': details.countries
}
results = nres.SearchResults()
for row in await conn.execute(sql, bind_params):
result = nres.create_from_placex_row(row, nres.SearchResult)
assert result
result.bbox = Bbox.from_wkb(row.bbox)
result.accuracy = row.accuracy
results.append(result)
return results