Added check for hstore extension

[nominatim.git] / nominatim / db / connection.py

diff --git a/nominatim/db/connection.py b/nominatim/db/connection.py
index 3bfc582d5667d62e4050f1e577e3f1f89769226a..12fc22d46841486c047cf341538ff81b5413cf3f 100644 (file)
--- a/nominatim/db/connection.py
+++ b/nominatim/db/connection.py
@@ -7,7 +7,7 @@
 """
 Specialised connection and cursor functions.
 """
-from typing import List, Optional, Any, Callable, ContextManager, Dict, cast, overload, Tuple
+from typing import Optional, Any, Callable, ContextManager, Dict, cast, overload, Tuple, Iterable
 import contextlib
 import logging
 import os
@@ -22,7 +22,7 @@ from nominatim.errors import UsageError
 
 LOG = logging.getLogger()
 
-class _Cursor(psycopg2.extras.DictCursor):
+class Cursor(psycopg2.extras.DictCursor):
     """ A cursor returning dict-like objects and providing specialised
         execution functions.
     """
@@ -31,13 +31,13 @@ class _Cursor(psycopg2.extras.DictCursor):
         """ Query execution that logs the SQL query when debugging is enabled.
         """
         if LOG.isEnabledFor(logging.DEBUG):
-            LOG.debug(self.mogrify(query, args).decode('utf-8')) # type: ignore
+            LOG.debug(self.mogrify(query, args).decode('utf-8'))
 
         super().execute(query, args)
 
 
-    def execute_values(self, sql: Query, argslist: List[Any],
-                       template: Optional[str] = None) -> None:
+    def execute_values(self, sql: Query, argslist: Iterable[Tuple[Any, ...]],
+                       template: Optional[Query] = None) -> None:
         """ Wrapper for the psycopg2 convenience function to execute
             SQL for a list of values.
         """
@@ -55,7 +55,7 @@ class _Cursor(psycopg2.extras.DictCursor):
         if self.rowcount != 1:
             raise RuntimeError("Query did not return a single row.")
 
-        result = self.fetchone() # type: ignore
+        result = self.fetchone()
         assert result is not None
 
         return result[0]
@@ -63,7 +63,7 @@ class _Cursor(psycopg2.extras.DictCursor):
 
     def drop_table(self, name: str, if_exists: bool = True, cascade: bool = False) -> None:
         """ Drop the table with the given name.
-            Set `if_exists` to False if a non-existant table should raise
+            Set `if_exists` to False if a non-existent table should raise
             an exception instead of just being ignored. If 'cascade' is set
             to True then all dependent tables are deleted as well.
         """
@@ -74,7 +74,7 @@ class _Cursor(psycopg2.extras.DictCursor):
         if cascade:
             sql += ' CASCADE'
 
-        self.execute(pysql.SQL(sql).format(pysql.Identifier(name))) # type: ignore
+        self.execute(pysql.SQL(sql).format(pysql.Identifier(name)))
 
 
 class Connection(psycopg2.extensions.connection):
@@ -82,18 +82,18 @@ class Connection(psycopg2.extensions.connection):
         adds convenience functions for administrating the database.
     """
     @overload # type: ignore[override]
-    def cursor(self) -> _Cursor:
+    def cursor(self) -> Cursor:
         ...
 
     @overload
-    def cursor(self, name: str) -> _Cursor:
+    def cursor(self, name: str) -> Cursor:
         ...
 
     @overload
     def cursor(self, cursor_factory: Callable[..., T_cursor]) -> T_cursor:
         ...
 
-    def cursor(self, cursor_factory  = _Cursor, **kwargs): # type: ignore
+    def cursor(self, cursor_factory  = Cursor, **kwargs): # type: ignore
         """ Return a new cursor. By default the specialised cursor is returned.
         """
         return super().cursor(cursor_factory=cursor_factory, **kwargs)
@@ -131,7 +131,7 @@ class Connection(psycopg2.extensions.connection):
                 return False
 
             if table is not None:
-                row = cur.fetchone() # type: ignore
+                row = cur.fetchone()
                 if row is None or not isinstance(row[0], str):
                     return False
                 return row[0] == table
@@ -141,7 +141,7 @@ class Connection(psycopg2.extensions.connection):
 
     def drop_table(self, name: str, if_exists: bool = True, cascade: bool = False) -> None:
         """ Drop the table with the given name.
-            Set `if_exists` to False if a non-existant table should raise
+            Set `if_exists` to False if a non-existent table should raise
             an exception instead of just being ignored.
         """
         with self.cursor() as cur:
@@ -174,6 +174,24 @@ class Connection(psycopg2.extensions.connection):
 
         return (int(version_parts[0]), int(version_parts[1]))
 
+    def hstore_version_tuple(self) -> Tuple[int, int]:
+        """ Return the hstore version installed in the database as a
+            tuple of (major, minor). Assumes that the hstore extension
+            has been installed already.
+        """
+        with self.cursor() as cur:
+            version = cur.scalar(
+                'SELECT extversion FROM pg_extension WHERE extname = %s',
+                ('hstore')
+            )
+
+        version_parts = version.split('.')
+        if len(version_parts) < 2:
+            raise UsageError(f"Error fetching hstore version. Bad format: {version}")
+
+        return (int(version_parts[0]), int(version_parts[1]))
+
+
 class ConnectionContext(ContextManager[Connection]):
     """ Context manager of the connection that also provides direct access
         to the underlying connection.
@@ -189,7 +207,7 @@ def connect(dsn: str) -> ConnectionContext:
     try:
         conn = psycopg2.connect(dsn, connection_factory=Connection)
         ctxmgr = cast(ConnectionContext, contextlib.closing(conn))
-        ctxmgr.connection = cast(Connection, conn)
+        ctxmgr.connection = conn
         return ctxmgr
     except psycopg2.OperationalError as err:
         raise UsageError(f"Cannot connect to database: {err}") from err
@@ -236,7 +254,7 @@ def get_pg_env(dsn: str,
     """
     env = dict(base_env if base_env is not None else os.environ)
 
-    for param, value in psycopg2.extensions.parse_dsn(dsn).items(): # type: ignore
+    for param, value in psycopg2.extensions.parse_dsn(dsn).items():
         if param in _PG_CONNECTION_STRINGS:
             env[_PG_CONNECTION_STRINGS[param]] = value
         else: