Merge pull request #2562 from lonvia/copyright-headers

[nominatim.git] / nominatim / tokenizer / icu_rule_loader.py

diff --git a/nominatim/tokenizer/icu_rule_loader.py b/nominatim/tokenizer/icu_rule_loader.py
index d3141bf7341691daba70c57db46ab6ed20256ae5..dcf119a323fb395750b1aea57a3c794dd2343955 100644 (file)
--- a/nominatim/tokenizer/icu_rule_loader.py
+++ b/nominatim/tokenizer/icu_rule_loader.py
@@ -1,61 +1,92 @@
+# 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.
 """
 """
 Helper class to create ICU rules from a configuration file.
 """

+import importlib

 import io
 import io

+import json

 import logging
 import logging

-import itertools
-from pathlib import Path
-import re
-
-import yaml
-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.errors import UsageError

-import nominatim.tokenizer.icu_variants as variants
+from nominatim.tokenizer.place_sanitizer import PlaceSanitizer
+from nominatim.tokenizer.icu_token_analysis import ICUTokenAnalysis
+import nominatim.tools.country_info

 
 LOG = logging.getLogger()
 
 
 LOG = logging.getLogger()
 

-def _flatten_yaml_list(content):
-    if not content:
-        return []
-
-    if not isinstance(content, list):
-        raise UsageError("List expected in ICU yaml configuration.")
-
-    output = []
-    for ele in content:
-        if isinstance(ele, list):
-            output.extend(_flatten_yaml_list(ele))
-        else:
-            output.append(ele)
+DBCFG_IMPORT_NORM_RULES = "tokenizer_import_normalisation"
+DBCFG_IMPORT_TRANS_RULES = "tokenizer_import_transliteration"
+DBCFG_IMPORT_ANALYSIS_RULES = "tokenizer_import_analysis_rules"

 
 

-    return output

 
 

-
-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:
     """ Compiler for ICU rules from a tokenizer configuration file.
     """
 
 
 
 class ICURuleLoader:
     """ Compiler for ICU rules from a tokenizer configuration file.
     """
 

-    def __init__(self, configfile):
-        self.configfile = configfile
-        self.variants = set()
+    def __init__(self, config):
+        rules = config.load_sub_configuration('icu_tokenizer.yaml',
+                                              config='TOKENIZER_CONFIG')
+
+        # Make sure country information is available to analyzers and sanatizers.
+        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 = _get_section(rules, 'token-analysis')
+        self._setup_analysis()
+
+        # Load optional sanitizer rule set.
+        self.sanitizer_rules = rules.get('sanitizers', [])
+
+
+    def load_config_from_db(self, conn):
+        """ 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))
+        self._setup_analysis()
+
+
+    def save_config_to_db(self, conn):
+        """ Save the part of the configuration that cannot be changed into
+            the database.
+        """
+        set_property(conn, DBCFG_IMPORT_NORM_RULES, self.normalization_rules)
+        set_property(conn, DBCFG_IMPORT_TRANS_RULES, self.transliteration_rules)
+        set_property(conn, DBCFG_IMPORT_ANALYSIS_RULES, json.dumps(self.analysis_rules))

 
 

-        if configfile.suffix == '.yaml':
-            self._load_from_yaml()
-        else:
-            raise UsageError("Unknown format of tokenizer configuration.")
+
+    def make_sanitizer(self):
+        """ Create a place sanitizer from the configured rules.
+        """
+        return PlaceSanitizer(self.sanitizer_rules)
+
+
+    def make_token_analysis(self):
+        """ Create a token analyser from the reviouly loaded rules.
+        """
+        return ICUTokenAnalysis(self.normalization_rules,
+                                self.transliteration_rules, self.analysis)

 
 
     def get_search_rules(self):
 
 
     def get_search_rules(self):


@@ -70,177 +101,66 @@ class ICURuleLoader:
         rules.write(self.transliteration_rules)
         return rules.getvalue()
 
         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_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_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
-
-    def _yaml_include_representer(self, loader, node):
-        value = loader.construct_scalar(node)
-
-        if Path(value).is_absolute():
-            content = Path(value).read_text()
-        else:
-            content = (self.configfile.parent / value).read_text()
-
-        return yaml.safe_load(content)
-
-
-    def _load_from_yaml(self):
-        yaml.add_constructor('!include', self._yaml_include_representer,
-                             Loader=yaml.SafeLoader)
-        rules = yaml.safe_load(self.configfile.read_text())
-
-        self.normalization_rules = self._cfg_to_icu_rules(rules, 'normalization')
-        self.transliteration_rules = self._cfg_to_icu_rules(rules, 'transliteration')
-        self._parse_variant_list(self._get_section(rules, 'variants'))
-

 
 

-    def _get_section(self, 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 '%s'.",
-                      section, str(self.configfile))
-            raise UsageError("Syntax error in tokenizer configuration file.")
+        self.analysis = {}

 
 

-        return rules[section]
+        if not isinstance(self.analysis_rules, list):
+            raise UsageError("Configuration section 'token-analysis' must be a list.")

 
 

+        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.
         """
         """ 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 ''
 
 
         if content is None:
             return ''
 

-        return ';'.join(_flatten_yaml_list(content)) + ';'
-
-
-    def _parse_variant_list(self, rules):
-        self.variants.clear()
-
-        if not rules:
-            return
-
-        rules = _flatten_yaml_list(rules)
-
-        vmaker = _VariantMaker(self.normalization_rules)
+        return ';'.join(flatten_config_list(content, section)) + ';'

 
 

-        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)