+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
"""
Helper class to create ICU rules from a configuration file.
"""
+from typing import Mapping, Any, Dict, Optional
import importlib
import io
import json
import logging
-import itertools
-import re
-from icu import Transliterator
-
-from nominatim.config import flatten_config_list
+from nominatim.config import flatten_config_list, Configuration
from nominatim.db.properties import set_property, get_property
+from nominatim.db.connection import Connection
from nominatim.errors import UsageError
from nominatim.tokenizer.place_sanitizer import PlaceSanitizer
-import nominatim.tokenizer.icu_variants as variants
+from nominatim.tokenizer.icu_token_analysis import ICUTokenAnalysis
+from nominatim.tokenizer.token_analysis.base import AnalysisModule, Analyser
+import nominatim.data.country_info
LOG = logging.getLogger()
DBCFG_IMPORT_ANALYSIS_RULES = "tokenizer_import_analysis_rules"
-def _get_section(rules, section):
+def _get_section(rules: Mapping[str, Any], section: str) -> Any:
""" Get the section named 'section' from the rules. If the section does
not exist, raise a usage error with a meaningful message.
"""
return rules[section]
-class VariantRule:
- """ Saves a single variant expansion.
-
- An expansion consists of the normalized replacement term and
- a dicitonary of properties that describe when the expansion applies.
- """
-
- def __init__(self, replacement, properties):
- self.replacement = replacement
- self.properties = properties or {}
-
-
class ICURuleLoader:
""" Compiler for ICU rules from a tokenizer configuration file.
"""
- def __init__(self, config):
+ def __init__(self, config: Configuration) -> None:
+ self.config = config
rules = config.load_sub_configuration('icu_tokenizer.yaml',
config='TOKENIZER_CONFIG')
+ # Make sure country information is available to analyzers and sanitizers.
+ nominatim.data.country_info.setup_country_config(config)
+
self.normalization_rules = self._cfg_to_icu_rules(rules, 'normalization')
self.transliteration_rules = self._cfg_to_icu_rules(rules, 'transliteration')
self.analysis_rules = _get_section(rules, 'token-analysis')
self.sanitizer_rules = rules.get('sanitizers', [])
- def load_config_from_db(self, conn):
+ def load_config_from_db(self, conn: Connection) -> None:
""" Get previously saved parts of the configuration from the
database.
"""
- self.normalization_rules = get_property(conn, DBCFG_IMPORT_NORM_RULES)
- self.transliteration_rules = get_property(conn, DBCFG_IMPORT_TRANS_RULES)
- self.analysis_rules = json.loads(get_property(conn, DBCFG_IMPORT_ANALYSIS_RULES))
+ rules = get_property(conn, DBCFG_IMPORT_NORM_RULES)
+ if rules is not None:
+ self.normalization_rules = rules
+
+ rules = get_property(conn, DBCFG_IMPORT_TRANS_RULES)
+ if rules is not None:
+ self.transliteration_rules = rules
+
+ rules = get_property(conn, DBCFG_IMPORT_ANALYSIS_RULES)
+ if rules:
+ self.analysis_rules = json.loads(rules)
+ else:
+ self.analysis_rules = []
self._setup_analysis()
- def save_config_to_db(self, conn):
+ def save_config_to_db(self, conn: Connection) -> None:
""" Save the part of the configuration that cannot be changed into
the database.
"""
set_property(conn, DBCFG_IMPORT_ANALYSIS_RULES, json.dumps(self.analysis_rules))
- def make_sanitizer(self):
+ def make_sanitizer(self) -> PlaceSanitizer:
""" Create a place sanitizer from the configured rules.
"""
- return PlaceSanitizer(self.sanitizer_rules)
+ return PlaceSanitizer(self.sanitizer_rules, self.config)
- def make_token_analysis(self):
+ def make_token_analysis(self) -> ICUTokenAnalysis:
""" Create a token analyser from the reviouly loaded rules.
"""
- return self.analysis[None].create(self.normalization_rules,
- self.transliteration_rules)
+ return ICUTokenAnalysis(self.normalization_rules,
+ self.transliteration_rules, self.analysis)
- def get_search_rules(self):
+ def get_search_rules(self) -> str:
""" Return the ICU rules to be used during search.
The rules combine normalization and transliteration.
"""
return rules.getvalue()
- def get_normalization_rules(self):
+ def get_normalization_rules(self) -> str:
""" Return rules for normalisation of a term.
"""
return self.normalization_rules
- def get_transliteration_rules(self):
+ def get_transliteration_rules(self) -> str:
""" Return the rules for converting a string into its asciii representation.
"""
return self.transliteration_rules
- def _setup_analysis(self):
+ def _setup_analysis(self) -> None:
""" Process the rules used for creating the various token analyzers.
"""
- self.analysis = {}
+ self.analysis: Dict[Optional[str], TokenAnalyzerRule] = {}
if not isinstance(self.analysis_rules, list):
raise UsageError("Configuration section 'token-analysis' must be a list.")
else:
LOG.fatal("ICU tokenizer configuration has two token "
"analyzers with id '%s'.", name)
- UsageError("Syntax error in ICU tokenizer config.")
+ raise UsageError("Syntax error in ICU tokenizer config.")
self.analysis[name] = TokenAnalyzerRule(section, self.normalization_rules)
@staticmethod
- def _cfg_to_icu_rules(rules, section):
+ def _cfg_to_icu_rules(rules: Mapping[str, Any], section: str) -> str:
""" Load an ICU ruleset from the given section. If the section is a
simple string, it is interpreted as a file name and the rules are
loaded verbatim from the given file. The filename is expected to be
and creates a new token analyzer on request.
"""
- def __init__(self, rules, normalization_rules):
+ def __init__(self, rules: Mapping[str, Any], normalization_rules: str) -> None:
# Find the analysis module
module_name = 'nominatim.tokenizer.token_analysis.' \
+ _get_section(rules, 'analyzer').replace('-', '_')
- analysis_mod = importlib.import_module(module_name)
- self._mod_create = analysis_mod.create
+ self._analysis_mod: AnalysisModule = importlib.import_module(module_name)
# Load the configuration.
- self.config = {}
- self._parse_variant_list(rules.get('variants'), normalization_rules)
-
-
- def create(self, normalization_rules, transliteration_rules):
- """ Create an analyzer from the given rules.
- """
- return self._mod_create(normalization_rules,
- transliteration_rules,
- self.config)
-
-
- def _parse_variant_list(self, rules, normalization_rules):
- vset = set()
-
- if not rules:
- return
-
- rules = flatten_config_list(rules, 'variants')
-
- vmaker = _VariantMaker(normalization_rules)
-
- properties = []
- for section in rules:
- # Create the property field and deduplicate against existing
- # instances.
- props = variants.ICUVariantProperties.from_rules(section)
- for existing in properties:
- if existing == props:
- props = existing
- break
- else:
- properties.append(props)
-
- for rule in (section.get('words') or []):
- vset.update(vmaker.compute(rule, props))
-
- self.config['variants'] = vset
-
-
-class _VariantMaker:
- """ Generater for all necessary ICUVariants from a single variant rule.
-
- All text in rules is normalized to make sure the variants match later.
- """
-
- def __init__(self, norm_rules):
- self.norm = Transliterator.createFromRules("rule_loader_normalization",
- norm_rules)
-
+ self.config = self._analysis_mod.configure(rules, normalization_rules)
- def compute(self, rule, props):
- """ Generator for all ICUVariant tuples from a single variant rule.
+ def create(self, normalizer: Any, transliterator: Any) -> Analyser:
+ """ Create a new analyser instance for the given rule.
"""
- parts = re.split(r'(\|)?([=-])>', rule)
- if len(parts) != 4:
- raise UsageError("Syntax error in variant rule: " + rule)
-
- decompose = parts[1] is None
- src_terms = [self._parse_variant_word(t) for t in parts[0].split(',')]
- repl_terms = (self.norm.transliterate(t.strip()) for t in parts[3].split(','))
-
- # If the source should be kept, add a 1:1 replacement
- if parts[2] == '-':
- for src in src_terms:
- if src:
- for froms, tos in _create_variants(*src, src[0], decompose):
- yield variants.ICUVariant(froms, tos, props)
-
- for src, repl in itertools.product(src_terms, repl_terms):
- if src and repl:
- for froms, tos in _create_variants(*src, repl, decompose):
- yield variants.ICUVariant(froms, tos, props)
-
-
- def _parse_variant_word(self, name):
- name = name.strip()
- match = re.fullmatch(r'([~^]?)([^~$^]*)([~$]?)', name)
- if match is None or (match.group(1) == '~' and match.group(3) == '~'):
- raise UsageError("Invalid variant word descriptor '{}'".format(name))
- norm_name = self.norm.transliterate(match.group(2))
- if not norm_name:
- return None
-
- return norm_name, match.group(1), match.group(3)
-
-
-_FLAG_MATCH = {'^': '^ ',
- '$': ' ^',
- '': ' '}
-
-
-def _create_variants(src, preflag, postflag, repl, decompose):
- if preflag == '~':
- postfix = _FLAG_MATCH[postflag]
- # suffix decomposition
- src = src + postfix
- repl = repl + postfix
-
- yield src, repl
- yield ' ' + src, ' ' + repl
-
- if decompose:
- yield src, ' ' + repl
- yield ' ' + src, repl
- elif postflag == '~':
- # prefix decomposition
- prefix = _FLAG_MATCH[preflag]
- src = prefix + src
- repl = prefix + repl
-
- yield src, repl
- yield src + ' ', repl + ' '
-
- if decompose:
- yield src, repl + ' '
- yield src + ' ', repl
- else:
- prefix = _FLAG_MATCH[preflag]
- postfix = _FLAG_MATCH[postflag]
-
- yield prefix + src + postfix, prefix + repl + postfix
+ return self._analysis_mod.create(normalizer, transliterator, self.config)
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