+# 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.
"""
+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.db.properties import set_property, get_property
from nominatim.errors import UsageError
-from nominatim.tokenizer.icu_name_processor import ICUNameProcessor
from nominatim.tokenizer.place_sanitizer import PlaceSanitizer
-import nominatim.tokenizer.icu_variants as variants
+from nominatim.tokenizer.icu_token_analysis import ICUTokenAnalysis
+import nominatim.tools.country_info
LOG = logging.getLogger()
DBCFG_IMPORT_ANALYSIS_RULES = "tokenizer_import_analysis_rules"
-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 _get_section(rules, section):
+ """ Get the section named 'section' from the rules. If the section does
+ not exist, raise a usage error with a meaningful message.
"""
+ if section not in rules:
+ LOG.fatal("Section '%s' not found in tokenizer config.", section)
+ raise UsageError("Syntax error in tokenizer configuration file.")
- def __init__(self, replacement, properties):
- self.replacement = replacement
- self.properties = properties or {}
+ return rules[section]
class ICURuleLoader:
rules = config.load_sub_configuration('icu_tokenizer.yaml',
config='TOKENIZER_CONFIG')
- self.variants = set()
+ # Make sure country information is available to analyzers and sanitizers.
+ nominatim.tools.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 = self._get_section(rules, 'variants')
- self._parse_variant_list()
+ self.analysis_rules = _get_section(rules, 'token-analysis')
+ self._setup_analysis()
# Load optional sanitizer rule set.
self.sanitizer_rules = rules.get('sanitizers', [])
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))
- self._parse_variant_list()
+ self._setup_analysis()
def save_config_to_db(self, conn):
def make_token_analysis(self):
""" Create a token analyser from the reviouly loaded rules.
"""
- return ICUNameProcessor(self.normalization_rules,
- self.transliteration_rules,
- self.variants)
+ return ICUTokenAnalysis(self.normalization_rules,
+ self.transliteration_rules, self.analysis)
def get_search_rules(self):
rules.write(self.transliteration_rules)
return rules.getvalue()
+
def get_normalization_rules(self):
""" Return rules for normalisation of a term.
"""
return self.normalization_rules
+
def get_transliteration_rules(self):
""" Return the rules for converting a string into its asciii representation.
"""
return self.transliteration_rules
- def get_replacement_pairs(self):
- """ Return the list of possible compound decompositions with
- application of abbreviations included.
- The result is a list of pairs: the first item is the sequence to
- replace, the second is a list of replacements.
- """
- return self.variants
-
- @staticmethod
- def _get_section(rules, section):
- """ Get the section named 'section' from the rules. If the section does
- not exist, raise a usage error with a meaningful message.
+ def _setup_analysis(self):
+ """ Process the rules used for creating the various token analyzers.
"""
- if section not in rules:
- LOG.fatal("Section '%s' not found in tokenizer config.", section)
- raise UsageError("Syntax error in tokenizer configuration file.")
+ self.analysis = {}
+
+ if not isinstance(self.analysis_rules, list):
+ raise UsageError("Configuration section 'token-analysis' must be a list.")
- return rules[section]
+ for section in self.analysis_rules:
+ name = section.get('id', None)
+ if name in self.analysis:
+ if name is None:
+ LOG.fatal("ICU tokenizer configuration has two default token analyzers.")
+ else:
+ LOG.fatal("ICU tokenizer configuration has two token "
+ "analyzers with id '%s'.", name)
+ raise UsageError("Syntax error in ICU tokenizer config.")
+ self.analysis[name] = TokenAnalyzerRule(section, self.normalization_rules)
- def _cfg_to_icu_rules(self, rules, section):
+ @staticmethod
+ def _cfg_to_icu_rules(rules, section):
""" 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
relative to the tokenizer rule file. If the section is a list then
each line is assumed to be a rule. All rules are concatenated and returned.
"""
- content = self._get_section(rules, section)
+ content = _get_section(rules, section)
if content is None:
return ''
return ';'.join(flatten_config_list(content, section)) + ';'
- def _parse_variant_list(self):
- rules = self.analysis_rules
-
- self.variants.clear()
-
- if not rules:
- return
-
- rules = flatten_config_list(rules, 'variants')
-
- vmaker = _VariantMaker(self.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 []):
- self.variants.update(vmaker.compute(rule, props))
-
-
-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.
+class TokenAnalyzerRule:
+ """ Factory for a single analysis module. The class saves the configuration
+ and creates a new token analyzer on request.
"""
- def __init__(self, norm_rules):
- self.norm = Transliterator.createFromRules("rule_loader_normalization",
- norm_rules)
+ def __init__(self, rules, normalization_rules):
+ # Find the analysis module
+ module_name = 'nominatim.tokenizer.token_analysis.' \
+ + _get_section(rules, 'analyzer').replace('-', '_')
+ analysis_mod = importlib.import_module(module_name)
+ self.create = analysis_mod.create
-
- def compute(self, rule, props):
- """ Generator for all ICUVariant tuples from a single variant 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
+ # Load the configuration.
+ self.config = analysis_mod.configure(rules, normalization_rules)
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