move module installation to legacy tokenizer

nominatim/tokenizer/legacy_tokenizer.py

@@ -1,16 +1,61 @@
 """
 Tokenizer implementing normalisation as used before Nominatim 4.
 """
+import logging
+import shutil
+
+import psycopg2
+
 from nominatim.db.connection import connect
 from nominatim.db import properties
+from nominatim.errors import UsageError
 
 DBCFG_NORMALIZATION = "tokenizer_normalization"
 
+LOG = logging.getLogger()
+
 def create(dsn, data_dir):
     """ Create a new instance of the tokenizer provided by this module.
     """
     return LegacyTokenizer(dsn, data_dir)
 
+
+def _install_module(src_dir, module_dir):
+    """ Copies the PostgreSQL normalisation module into the project
+        directory if necessary. For historical reasons the module is
+        saved in the '/module' subdirectory and not with the other tokenizer
+        data.
+
+        The function detects when the installation is run from the
+        build directory. It doesn't touch the module in that case.
+    """
+    if module_dir.exists() and src_dir.samefile(module_dir):
+        LOG.info('Running from build directory. Leaving database module as is.')
+        return
+
+    if not module_dir.exists():
+        module_dir.mkdir()
+
+    destfile = module_dir / 'nominatim.so'
+    shutil.copy(str(src_dir / 'nominatim.so'), str(destfile))
+    destfile.chmod(0o755)
+
+    LOG.info('Database module installed at %s', str(destfile))
+
+
+def _check_module(module_dir, conn):
+    with conn.cursor() as cur:
+        try:
+            cur.execute("""CREATE FUNCTION nominatim_test_import_func(text)
+                           RETURNS text AS '{}/nominatim.so', 'transliteration'
+                           LANGUAGE c IMMUTABLE STRICT;
+                           DROP FUNCTION nominatim_test_import_func(text)
+                        """.format(module_dir))
+        except psycopg2.DatabaseError as err:
+            LOG.fatal("Error accessing database module: %s", err)
+            raise UsageError("Database module cannot be accessed.") from err
+
+
 class LegacyTokenizer:
     """ The legacy tokenizer uses a special PostgreSQL module to normalize
         names and queries. The tokenizer thus implements normalization through
@@ -29,12 +74,24 @@ class LegacyTokenizer:
             This copies all necessary data in the project directory to make
             sure the tokenizer remains stable even over updates.
         """
+        # Find and optionally install the PsotgreSQL normalization module.
+        if config.DATABASE_MODULE_PATH:
+            LOG.info("Using custom path for database module at '%s'",
+                     config.DATABASE_MODULE_PATH)
+            module_dir = config.DATABASE_MODULE_PATH
+        else:
+            _install_module(config.lib_dir.module, config.project_dir / 'module')
+            module_dir = config.project_dir / 'module'
+
         self.normalization = config.TERM_NORMALIZATION
 
-        # Stable configuration is saved in the database.
         with connect(self.dsn) as conn:
-            properties.set_property(conn, DBCFG_NORMALIZATION,
-                                    self.normalization)
+            _check_module(module_dir, conn)
+
+            # Stable configuration is saved in the database.
+            properties.set_property(conn, DBCFG_NORMALIZATION, self.normalization)
+
+            conn.commit()
 
 
     def init_from_project(self):