selected lambdas for search

nominatim/api/search/db_searches.py

@@ -7,14 +7,14 @@
 """
 Implementation of the acutal database accesses for forward search.
 """
-from typing import List, Tuple, AsyncIterator, Dict, Any
+from typing import List, Tuple, AsyncIterator, Dict, Any, Callable
 import abc
 
 import sqlalchemy as sa
 from sqlalchemy.dialects.postgresql import ARRAY, array_agg
 
 from nominatim.typing import SaFromClause, SaScalarSelect, SaColumn, \
-                             SaExpression, SaSelect, SaRow, SaBind
+                             SaExpression, SaSelect, SaLambdaSelect, SaRow, SaBind
 from nominatim.api.connection import SearchConnection
 from nominatim.api.types import SearchDetails, DataLayer, GeometryFormat, Bbox
 import nominatim.api.results as nres
@@ -46,9 +46,14 @@ 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')
-EXCLUDED_PARAM: SaBind = sa.bindparam('excluded')
 COUNTRIES_PARAM: SaBind = sa.bindparam('countries')
 
+def _within_near(t: SaFromClause) -> Callable[[], SaExpression]:
+    return lambda: t.c.geometry.ST_DWithin(NEAR_PARAM, NEAR_RADIUS_PARAM)
+
+def _exclude_places(t: SaFromClause) -> Callable[[], SaExpression]:
+    return lambda: t.c.place_id.not_in(sa.bindparam('excluded'))
+
 def _select_placex(t: SaFromClause) -> SaSelect:
     return sa.select(t.c.place_id, t.c.osm_type, t.c.osm_id, t.c.name,
                      t.c.class_, t.c.type,
@@ -60,10 +65,7 @@ def _select_placex(t: SaFromClause) -> SaSelect:
                      t.c.geometry.ST_Expand(0).label('bbox'))
 
 
-def _add_geometry_columns(sql: SaSelect, col: SaColumn, details: SearchDetails) -> SaSelect:
-    if not details.geometry_output:
-        return sql
-
+def _add_geometry_columns(sql: SaLambdaSelect, col: SaColumn, details: SearchDetails) -> SaSelect:
     out = []
 
     if details.geometry_simplification > 0.0:
@@ -96,7 +98,7 @@ def _make_interpolation_subquery(table: SaFromClause, inner: SaFromClause,
                   for n in numerals)))
 
     if details.excluded:
-        sql = sql.where(table.c.place_id.not_in(EXCLUDED_PARAM))
+        sql = sql.where(_exclude_places(table))
 
     return sql.scalar_subquery()
 
@@ -150,7 +152,8 @@ async def _get_placex_housenumbers(conn: SearchConnection,
     t = conn.t.placex
     sql = _select_placex(t).where(t.c.place_id.in_(place_ids))
 
-    sql = _add_geometry_columns(sql, t.c.geometry, details)
+    if details.geometry_output:
+        sql = _add_geometry_columns(sql, t.c.geometry, details)
 
     for row in await conn.execute(sql):
         result = nres.create_from_placex_row(row, nres.SearchResult)
@@ -294,7 +297,7 @@ class NearSearch(AbstractSearch):
         if details.countries:
             sql = sql.where(t.c.country_code.in_(COUNTRIES_PARAM))
         if details.excluded:
-            sql = sql.where(t.c.place_id.not_in(EXCLUDED_PARAM))
+            sql = sql.where(_exclude_places(t))
         if details.layers is not None:
             sql = sql.where(_filter_by_layer(t, details.layers))
 
@@ -328,10 +331,22 @@ class PoiSearch(AbstractSearch):
 
         if details.near and details.near_radius is not None and details.near_radius < 0.2:
             # simply search in placex table
-            sql = _select_placex(t) \
-                      .where(t.c.linked_place_id == None) \
-                      .where(t.c.geometry.ST_DWithin(NEAR_PARAM, NEAR_RADIUS_PARAM)) \
-                      .order_by(t.c.centroid.ST_Distance(NEAR_PARAM))
+            def _base_query() -> SaSelect:
+                return _select_placex(t) \
+                           .where(t.c.linked_place_id == None) \
+                           .where(t.c.geometry.ST_DWithin(NEAR_PARAM, NEAR_RADIUS_PARAM)) \
+                           .order_by(t.c.centroid.ST_Distance(NEAR_PARAM)) \
+                           .limit(LIMIT_PARAM)
+
+            classtype = self.categories.values
+            if len(classtype) == 1:
+                cclass, ctype = classtype[0]
+                sql: SaLambdaSelect = sa.lambda_stmt(lambda: _base_query()
+                                                 .where(t.c.class_ == cclass)
+                                                 .where(t.c.type == ctype))
+            else:
+                sql = _base_query().where(sa.or_(*(sa.and_(t.c.class_ == cls, t.c.type == typ)
+                                                   for cls, typ in classtype)))
 
             if self.countries:
                 sql = sql.where(t.c.country_code.in_(self.countries.values))
@@ -339,15 +354,6 @@ class PoiSearch(AbstractSearch):
             if details.viewbox is not None and details.bounded_viewbox:
                 sql = sql.where(t.c.geometry.intersects(VIEWBOX_PARAM))
 
-            classtype = self.categories.values
-            if len(classtype) == 1:
-                sql = sql.where(t.c.class_ == classtype[0][0]) \
-                         .where(t.c.type == classtype[0][1])
-            else:
-                sql = sql.where(sa.or_(*(sa.and_(t.c.class_ == cls, t.c.type == typ)
-                                         for cls, typ in classtype)))
-
-            sql = sql.limit(LIMIT_PARAM)
             rows.extend(await conn.execute(sql, bind_params))
         else:
             # use the class type tables
@@ -398,20 +404,22 @@ class CountrySearch(AbstractSearch):
         """
         t = conn.t.placex
 
-        sql = _select_placex(t)\
-                .where(t.c.country_code.in_(self.countries.values))\
-                .where(t.c.rank_address == 4)
+        ccodes = self.countries.values
+        sql: SaLambdaSelect = sa.lambda_stmt(lambda: _select_placex(t)\
+                .where(t.c.country_code.in_(ccodes))\
+                .where(t.c.rank_address == 4))
 
-        sql = _add_geometry_columns(sql, t.c.geometry, details)
+        if details.geometry_output:
+            sql = _add_geometry_columns(sql, t.c.geometry, details)
 
         if details.excluded:
-            sql = sql.where(t.c.place_id.not_in(EXCLUDED_PARAM))
+            sql = sql.where(_exclude_places(t))
 
         if details.viewbox is not None and details.bounded_viewbox:
-            sql = sql.where(t.c.geometry.intersects(VIEWBOX_PARAM))
+            sql = sql.where(lambda: t.c.geometry.intersects(VIEWBOX_PARAM))
 
         if details.near is not None and details.near_radius is not None:
-            sql = sql.where(t.c.geometry.ST_DWithin(NEAR_PARAM, NEAR_RADIUS_PARAM))
+            sql = sql.where(_within_near(t))
 
         results = nres.SearchResults()
         for row in await conn.execute(sql, _details_to_bind_params(details)):
@@ -445,7 +453,7 @@ class CountrySearch(AbstractSearch):
         if details.viewbox is not None and details.bounded_viewbox:
             sql = sql.where(tgrid.c.geometry.intersects(VIEWBOX_PARAM))
         if details.near is not None and details.near_radius is not None:
-            sql = sql.where(tgrid.c.geometry.ST_DWithin(NEAR_PARAM, NEAR_RADIUS_PARAM))
+            sql = sql.where(_within_near(tgrid))
 
         sub = sql.subquery('grid')
 
@@ -484,14 +492,17 @@ class PostcodeSearch(AbstractSearch):
         """ Find results for the search in the database.
         """
         t = conn.t.postcode
+        pcs = self.postcodes.values
 
-        sql = sa.select(t.c.place_id, t.c.parent_place_id,
+        sql: SaLambdaSelect = sa.lambda_stmt(lambda:
+                sa.select(t.c.place_id, t.c.parent_place_id,
                         t.c.rank_search, t.c.rank_address,
                         t.c.postcode, t.c.country_code,
-                        t.c.geometry.label('centroid'))\
-                .where(t.c.postcode.in_(self.postcodes.values))
+                        t.c.geometry.label('centroid'))
+                .where(t.c.postcode.in_(pcs)))
 
-        sql = _add_geometry_columns(sql, t.c.geometry, details)
+        if details.geometry_output:
+            sql = _add_geometry_columns(sql, t.c.geometry, details)
 
         penalty: SaExpression = sa.literal(self.penalty)
 
@@ -505,14 +516,14 @@ class PostcodeSearch(AbstractSearch):
 
         if details.near is not None:
             if details.near_radius is not None:
-                sql = sql.where(t.c.geometry.ST_DWithin(NEAR_PARAM, NEAR_RADIUS_PARAM))
+                sql = sql.where(_within_near(t))
             sql = sql.order_by(t.c.geometry.ST_Distance(NEAR_PARAM))
 
         if self.countries:
             sql = sql.where(t.c.country_code.in_(self.countries.values))
 
         if details.excluded:
-            sql = sql.where(t.c.place_id.not_in(EXCLUDED_PARAM))
+            sql = sql.where(_exclude_places(t))
 
         if self.lookups:
             assert len(self.lookups) == 1
@@ -562,21 +573,23 @@ class PlaceSearch(AbstractSearch):
                      details: SearchDetails) -> nres.SearchResults:
         """ Find results for the search in the database.
         """
-        t = conn.t.placex.alias('p')
-        tsearch = conn.t.search_name.alias('s')
+        t = conn.t.placex
+        tsearch = conn.t.search_name
 
-        sql = sa.select(t.c.place_id, t.c.osm_type, t.c.osm_id, t.c.name,
-                        t.c.class_, t.c.type,
-                        t.c.address, t.c.extratags,
-                        t.c.housenumber, t.c.postcode, t.c.country_code,
-                        t.c.wikipedia,
-                        t.c.parent_place_id, t.c.rank_address, t.c.rank_search,
-                        t.c.centroid,
-                        t.c.geometry.ST_Expand(0).label('bbox'))\
-                .where(t.c.place_id == tsearch.c.place_id)
+        sql: SaLambdaSelect = sa.lambda_stmt(lambda:
+                  sa.select(t.c.place_id, t.c.osm_type, t.c.osm_id, t.c.name,
+                            t.c.class_, t.c.type,
+                            t.c.address, t.c.extratags,
+                            t.c.housenumber, t.c.postcode, t.c.country_code,
+                            t.c.wikipedia,
+                            t.c.parent_place_id, t.c.rank_address, t.c.rank_search,
+                            t.c.centroid,
+                            t.c.geometry.ST_Expand(0).label('bbox'))
+                   .where(t.c.place_id == tsearch.c.place_id))
 
 
-        sql = _add_geometry_columns(sql, t.c.geometry, details)
+        if details.geometry_output:
+            sql = _add_geometry_columns(sql, t.c.geometry, details)
 
         penalty: SaExpression = sa.literal(self.penalty)
         for ranking in self.rankings:
@@ -592,18 +605,19 @@ class PlaceSearch(AbstractSearch):
             # if a postcode is given, don't search for state or country level objects
             sql = sql.where(tsearch.c.address_rank > 9)
             tpc = conn.t.postcode
+            pcs = self.postcodes.values
             if self.expected_count > 1000:
                 # Many results expected. Restrict by postcode.
-                sql = sql.where(sa.select(tpc.c.postcode)
-                                  .where(tpc.c.postcode.in_(self.postcodes.values))
+                sql = sql.where(lambda: sa.select(tpc.c.postcode)
+                                  .where(tpc.c.postcode.in_(pcs))
                                   .where(tsearch.c.centroid.ST_DWithin(tpc.c.geometry, 0.12))
                                   .exists())
 
             # Less results, only have a preference for close postcodes
             pc_near = sa.select(sa.func.min(tpc.c.geometry.ST_Distance(tsearch.c.centroid)))\
-                      .where(tpc.c.postcode.in_(self.postcodes.values))\
+                      .where(tpc.c.postcode.in_(pcs))\
                       .scalar_subquery()
-            penalty += sa.case((t.c.postcode.in_(self.postcodes.values), 0.0),
+            penalty += sa.case((t.c.postcode.in_(pcs), 0.0),
                                else_=sa.func.coalesce(pc_near, 2.0))
 
         if details.viewbox is not None:
@@ -633,7 +647,7 @@ class PlaceSearch(AbstractSearch):
             hnr_regexp = f"\\m({'|'.join(self.housenumbers.values)})\\M"
             sql = sql.where(tsearch.c.address_rank.between(16, 30))\
                      .where(sa.or_(tsearch.c.address_rank < 30,
-                                  t.c.housenumber.op('~*')(hnr_regexp)))
+                                   t.c.housenumber.op('~*')(hnr_regexp)))
 
             # Cross check for housenumbers, need to do that on a rather large
             # set. Worst case there are 40.000 main streets in OSM.
@@ -649,13 +663,13 @@ class PlaceSearch(AbstractSearch):
                           .where(thnr.c.indexed_status == 0)
 
             if details.excluded:
-                place_sql = place_sql.where(thnr.c.place_id.not_in(EXCLUDED_PARAM))
+                place_sql = place_sql.where(_exclude_places(thnr))
             if self.qualifiers:
                 place_sql = place_sql.where(self.qualifiers.sql_restrict(thnr))
 
             numerals = [int(n) for n in self.housenumbers.values if n.isdigit()]
-            interpol_sql: SaExpression
-            tiger_sql: SaExpression
+            interpol_sql: SaColumn
+            tiger_sql: SaColumn
             if numerals and \
                (not self.qualifiers or ('place', 'house') in self.qualifiers.values):
                 # Housenumbers from interpolations
@@ -667,8 +681,8 @@ class PlaceSearch(AbstractSearch):
                                                                   numerals, details)
                                     ), else_=None)
             else:
-                interpol_sql = sa.literal_column('NULL')
-                tiger_sql = sa.literal_column('NULL')
+                interpol_sql = sa.null()
+                tiger_sql = sa.null()
 
             unsort = sa.select(inner, place_sql.scalar_subquery().label('placex_hnr'),
                                interpol_sql.label('interpol_hnr'),
@@ -685,7 +699,7 @@ class PlaceSearch(AbstractSearch):
             if self.qualifiers:
                 sql = sql.where(self.qualifiers.sql_restrict(t))
             if details.excluded:
-                sql = sql.where(tsearch.c.place_id.not_in(EXCLUDED_PARAM))
+                sql = sql.where(_exclude_places(tsearch))
             if details.min_rank > 0:
                 sql = sql.where(sa.or_(tsearch.c.address_rank >= MIN_RANK_PARAM,
                                        tsearch.c.search_rank >= MIN_RANK_PARAM))