introduce external processing in indexer

Indexing is now split into three parts: first a preparation step
that collects the necessary information from the database and
returns it to Python. In a second step the data is transformed
within Python as necessary and then returned to the database
through the usual UPDATE which now not only sets the indexed_status
but also other fields. The third step comprises the address
computation which is still done inside the update trigger in
the database.

The second processing step doesn't do anything useful yet.

test/bdd/steps/nominatim_environment.py

@@ -106,9 +106,19 @@ class NominatimEnvironment:
             self.website_dir.cleanup()
 
         self.website_dir = tempfile.TemporaryDirectory()
-        cfg = Configuration(None, self.src_dir / 'settings', environ=self.test_env)
-        cfg.lib_dir.php = self.src_dir / 'lib-php'
-        refresh.setup_website(Path(self.website_dir.name) / 'website', cfg)
+        refresh.setup_website(Path(self.website_dir.name) / 'website',
+                              self.get_test_config())
+
+
+    def get_test_config(self):
+        cfg = Configuration(Path(self.website_dir.name), self.src_dir / 'settings',
+                            environ=self.test_env)
+        cfg.set_libdirs(module=self.build_dir / 'module',
+                        osm2pgsql=self.build_dir / 'osm2pgsql' / 'osm2pgsql',
+                        php=self.src_dir / 'lib-php',
+                        sql=self.src_dir / 'lib-sql',
+                        data=self.src_dir / 'data')
+        return cfg
 
     def get_libpq_dsn(self):
         dsn = self.test_env['NOMINATIM_DATABASE_DSN']

test/bdd/steps/steps_db_ops.py

@@ -7,6 +7,7 @@ from place_inserter import PlaceColumn
 from table_compare import NominatimID, DBRow
 
 from nominatim.indexer import indexer
+from nominatim.tokenizer import factory as tokenizer_factory
 
 def check_database_integrity(context):
     """ Check some generic constraints on the tables.
@@ -86,6 +87,9 @@ def add_data_to_planet_ways(context):
 def import_and_index_data_from_place_table(context):
     """ Import data previously set up in the place table.
     """
+    nctx = context.nominatim
+
+    tokenizer = tokenizer_factory.create_tokenizer(nctx.get_test_config())
     context.nominatim.copy_from_place(context.db)
 
     # XXX use tool function as soon as it is ported