Nominatim/nominatim/tokenizer/factory.py
Sarah Hoffmann 3eb4d88057 boilerplate for PHP code of tokenizer
This adds an installation step for PHP code for the tokenizer. The
PHP code is split in two parts. The updateable code is found in
lib-php. The tokenizer installs an additional script in the
project directory which then includes the code from lib-php and
defines all settings that are static to the database. The website
code then always includes the PHP from the project directory.
2021-04-30 11:31:52 +02:00

89 lines
3.0 KiB
Python

"""
Functions for creating a tokenizer or initialising the right one for an
existing database.
A tokenizer is something that is bound to the lifetime of a database. It
can be choosen and configured before the intial import but then needs to
be used consistently when querying and updating the database.
This module provides the functions to create and configure a new tokenizer
as well as instanciating the appropriate tokenizer for updating an existing
database.
A tokenizer usually also includes PHP code for querying. The appropriate PHP
normalizer module is installed, when the tokenizer is created.
"""
import logging
import importlib
from ..errors import UsageError
from ..db import properties
from ..db.connection import connect
LOG = logging.getLogger()
def _import_tokenizer(name):
""" Load the tokenizer.py module from project directory.
"""
try:
return importlib.import_module('nominatim.tokenizer.' + name + '_tokenizer')
except ModuleNotFoundError as exp:
LOG.fatal("No tokenizer named '%s' available. "
"Check the setting of NOMINATIM_TOKENIZER.", name)
raise UsageError('Tokenizer not found') from exp
def create_tokenizer(config, init_db=True, module_name=None):
""" Create a new tokenizer as defined by the given configuration.
The tokenizer data and code is copied into the 'tokenizer' directory
of the project directory and the tokenizer loaded from its new location.
"""
if module_name is None:
module_name = config.TOKENIZER
# Create the directory for the tokenizer data
basedir = config.project_dir / 'tokenizer'
if not basedir.exists():
basedir.mkdir()
elif not basedir.is_dir():
LOG.fatal("Tokenizer directory '%s' cannot be created.", basedir)
raise UsageError("Tokenizer setup failed.")
# Import and initialize the tokenizer.
tokenizer_module = _import_tokenizer(module_name)
tokenizer = tokenizer_module.create(config.get_libpq_dsn(), basedir)
tokenizer.init_new_db(config, init_db=init_db)
with connect(config.get_libpq_dsn()) as conn:
properties.set_property(conn, 'tokenizer', module_name)
return tokenizer
def get_tokenizer_for_db(config):
""" Instantiate a tokenizer for an existing database.
The function looks up the appropriate tokenizer in the database
and initialises it.
"""
basedir = config.project_dir / 'tokenizer'
if not basedir.is_dir():
LOG.fatal("Cannot find tokenizer data in '%s'.", basedir)
raise UsageError('Cannot initialize tokenizer.')
with connect(config.get_libpq_dsn()) as conn:
name = properties.get_property(conn, 'tokenizer')
if name is None:
LOG.fatal("Tokenizer was not set up properly. Database property missing.")
raise UsageError('Cannot initialize tokenizer.')
tokenizer_module = _import_tokenizer(name)
tokenizer = tokenizer_module.create(config.get_libpq_dsn(), basedir)
tokenizer.init_from_project()
return tokenizer