"""
Tokenizer implementing normalisation as used before Nominatim 4.
"""
+import logging
+import shutil
+
+import psycopg2
+import psycopg2.extras
+
from nominatim.db.connection import connect
from nominatim.db import properties
+from nominatim.db import utils as db_utils
+from nominatim.db.sql_preprocessor import SQLPreprocessor
+from nominatim.errors import UsageError
DBCFG_NORMALIZATION = "tokenizer_normalization"
+DBCFG_MAXWORDFREQ = "tokenizer_maxwordfreq"
+
+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(config_module_path, 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.
+ """
+ # Custom module locations are simply used as is.
+ if config_module_path:
+ LOG.info("Using custom path for database module at '%s'", config_module_path)
+ return config_module_path
+
+ # Compatibility mode for builddir installations.
+ if module_dir.exists() and src_dir.samefile(module_dir):
+ LOG.info('Running from build directory. Leaving database module as is.')
+ return module_dir
+
+ # In any other case install the module in the project directory.
+ 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))
+
+ return module_dir
+
+
+def _check_module(module_dir, conn):
+ """ Try to use the PostgreSQL module to confirm that it is correctly
+ installed and accessible from PostgreSQL.
+ """
+ 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
This copies all necessary data in the project directory to make
sure the tokenizer remains stable even over updates.
"""
+ module_dir = _install_module(config.DATABASE_MODULE_PATH,
+ config.lib_dir.module,
+ 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)
+ self._save_config(conn, config)
+ conn.commit()
+
+ self.update_sql_functions(config)
+ self._init_db_tables(config)
def init_from_project(self):
"""
with connect(self.dsn) as conn:
self.normalization = properties.get_property(conn, DBCFG_NORMALIZATION)
+
+
+ def update_sql_functions(self, config):
+ """ Reimport the SQL functions for this tokenizer.
+ """
+ with connect(self.dsn) as conn:
+ max_word_freq = properties.get_property(conn, DBCFG_MAXWORDFREQ)
+ modulepath = config.DATABASE_MODULE_PATH or \
+ str((config.project_dir / 'module').resolve())
+ sqlp = SQLPreprocessor(conn, config)
+ sqlp.run_sql_file(conn, 'tokenizer/legacy_tokenizer.sql',
+ max_word_freq=max_word_freq,
+ modulepath=modulepath)
+
+
+ def migrate_database(self, config):
+ """ Initialise the project directory of an existing database for
+ use with this tokenizer.
+
+ This is a special migration function for updating existing databases
+ to new software versions.
+ """
+ module_dir = _install_module(config.DATABASE_MODULE_PATH,
+ config.lib_dir.module,
+ config.project_dir / 'module')
+
+ with connect(self.dsn) as conn:
+ _check_module(module_dir, conn)
+ self._save_config(conn, config)
+
+
+ def name_analyzer(self):
+ """ Create a new analyzer for tokenizing names and queries
+ using this tokinzer. Analyzers are context managers and should
+ be used accordingly:
+
+ ```
+ with tokenizer.name_analyzer() as analyzer:
+ analyser.tokenize()
+ ```
+
+ When used outside the with construct, the caller must ensure to
+ call the close() function before destructing the analyzer.
+
+ Analyzers are not thread-safe. You need to instantiate one per thread.
+ """
+ return LegacyNameAnalyzer(self.dsn)
+
+
+ def _init_db_tables(self, config):
+ """ Set up the word table and fill it with pre-computed word
+ frequencies.
+ """
+ with connect(self.dsn) as conn:
+ sqlp = SQLPreprocessor(conn, config)
+ sqlp.run_sql_file(conn, 'tokenizer/legacy_tokenizer_tables.sql')
+ conn.commit()
+
+ LOG.warning("Precomputing word tokens")
+ db_utils.execute_file(self.dsn, config.lib_dir.data / 'words.sql')
+
+
+ def _save_config(self, conn, config):
+ """ Save the configuration that needs to remain stable for the given
+ database as database properties.
+ """
+ properties.set_property(conn, DBCFG_NORMALIZATION, self.normalization)
+ properties.set_property(conn, DBCFG_MAXWORDFREQ, config.MAX_WORD_FREQUENCY)
+
+
+
+class LegacyNameAnalyzer:
+ """ The legacy analyzer uses the special Postgresql module for
+ splitting names.
+
+ Each instance opens a connection to the database to request the
+ normalization.
+ """
+
+ def __init__(self, dsn):
+ self.conn = connect(dsn).connection
+ self.conn.autocommit = True
+ psycopg2.extras.register_hstore(self.conn)
+
+
+ def __enter__(self):
+ return self
+
+
+ def __exit__(self, exc_type, exc_value, traceback):
+ self.close()
+
+
+ def close(self):
+ """ Free all resources used by the analyzer.
+ """
+ if self.conn:
+ self.conn.close()
+ self.conn = None
+
+ def process_place(self, place):
+ """ Determine tokenizer information about the given place.
+
+ Returns a JSON-serialisable structure that will be handed into
+ the database via the token_info field.
+ """
+ return {}
projects / nominatim.git / blobdiff