"""
Extended SQLAlchemy connection class that also includes access to the schema.
"""
-from typing import cast, Any, Mapping, Sequence, Union, Dict, Optional, Set
+from typing import cast, Any, Mapping, Sequence, Union, Dict, Optional, Set, \
+ Awaitable, Callable, TypeVar
import sqlalchemy as sa
-from geoalchemy2 import Geometry
from sqlalchemy.ext.asyncio import AsyncConnection
from nominatim.typing import SaFromClause
from nominatim.db.sqlalchemy_schema import SearchTables
+from nominatim.db.sqlalchemy_types import Geometry
from nominatim.api.logging import log
+T = TypeVar('T')
+
class SearchConnection:
""" An extended SQLAlchemy connection class, that also contains
then table definitions. The underlying asynchronous SQLAlchemy
) -> Any:
""" Execute a 'scalar()' query on the connection.
"""
- log().sql(self.connection, sql)
+ log().sql(self.connection, sql, params)
return await self.connection.scalar(sql, params)
) -> 'sa.Result[Any]':
""" Execute a 'execute()' query on the connection.
"""
- log().sql(self.connection, sql)
+ log().sql(self.connection, sql, params)
return await self.connection.execute(sql, params)
Raises a ValueError if the property does not exist.
"""
- if name.startswith('DB:'):
- raise ValueError(f"Illegal property value '{name}'.")
+ lookup_name = f'DBPROP:{name}'
- if cached and name in self._property_cache:
- return cast(str, self._property_cache[name])
+ if cached and lookup_name in self._property_cache:
+ return cast(str, self._property_cache[lookup_name])
sql = sa.select(self.t.properties.c.value)\
.where(self.t.properties.c.property == name)
if value is None:
raise ValueError(f"Property '{name}' not found in database.")
- self._property_cache[name] = cast(str, value)
+ self._property_cache[lookup_name] = cast(str, value)
return cast(str, value)
return self._property_cache['DB:server_version']
+ async def get_cached_value(self, group: str, name: str,
+ factory: Callable[[], Awaitable[T]]) -> T:
+ """ Access the cache for this Nominatim instance.
+ Each cache value needs to belong to a group and have a name.
+ This function is for internal API use only.
+
+ `factory` is an async callback function that produces
+ the value if it is not already cached.
+
+ Returns the cached value or the result of factory (also caching
+ the result).
+ """
+ full_name = f'{group}:{name}'
+
+ if full_name in self._property_cache:
+ return cast(T, self._property_cache[full_name])
+
+ value = await factory()
+ self._property_cache[full_name] = value
+
+ return value
+
+
async def get_class_table(self, cls: str, typ: str) -> Optional[SaFromClause]:
""" Lookup up if there is a classtype table for the given category
and return a SQLAlchemy table for it, if it exists.
return sa.Table(tablename, self.t.meta,
sa.Column('place_id', sa.BigInteger),
- sa.Column('centroid', Geometry(srid=4326, spatial_index=False)))
+ sa.Column('centroid', Geometry))