Merge remote-tracking branch 'upstream/master'

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

diff --git a/nominatim/tokenizer/icu_tokenizer.py b/nominatim/tokenizer/icu_tokenizer.py
index 2af0bcb257ad214f3e67621a7ac1aaa83b7092d1..bf5544ed0c06064946bef2b48fa9c217a5312c29 100644 (file)
--- a/nominatim/tokenizer/icu_tokenizer.py
+++ b/nominatim/tokenizer/icu_tokenizer.py
@@ -1,3 +1,9 @@
+# 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.

 """
 Tokenizer implementing normalisation as used before Nominatim 4 but using
 libICU instead of the PostgreSQL module.
 """
 Tokenizer implementing normalisation as used before Nominatim 4 but using
 libICU instead of the PostgreSQL module.


@@ -9,7 +15,6 @@ import re
 from textwrap import dedent
 
 from nominatim.db.connection import connect
 from textwrap import dedent
 
 from nominatim.db.connection import connect

-from nominatim.db.properties import set_property, get_property

 from nominatim.db.utils import CopyBuffer
 from nominatim.db.sql_preprocessor import SQLPreprocessor
 from nominatim.indexer.place_info import PlaceInfo
 from nominatim.db.utils import CopyBuffer
 from nominatim.db.sql_preprocessor import SQLPreprocessor
 from nominatim.indexer.place_info import PlaceInfo


@@ -36,7 +41,6 @@ class LegacyICUTokenizer(AbstractTokenizer):
         self.dsn = dsn
         self.data_dir = data_dir
         self.loader = None
         self.dsn = dsn
         self.data_dir = data_dir
         self.loader = None

-        self.term_normalization = None

 
 
     def init_new_db(self, config, init_db=True):
 
 
     def init_new_db(self, config, init_db=True):


@@ -47,9 +51,7 @@ class LegacyICUTokenizer(AbstractTokenizer):
         """
         self.loader = ICURuleLoader(config)
 
         """
         self.loader = ICURuleLoader(config)
 

-        self.term_normalization = config.TERM_NORMALIZATION
-
-        self._install_php(config.lib_dir.php)
+        self._install_php(config.lib_dir.php, overwrite=True)

         self._save_config()
 
         if init_db:
         self._save_config()
 
         if init_db:


@@ -64,13 +66,17 @@ class LegacyICUTokenizer(AbstractTokenizer):
 
         with connect(self.dsn) as conn:
             self.loader.load_config_from_db(conn)
 
         with connect(self.dsn) as conn:
             self.loader.load_config_from_db(conn)

-            self.term_normalization = get_property(conn, DBCFG_TERM_NORMALIZATION)
+
+        self._install_php(config.lib_dir.php, overwrite=False)

 
 
 
 

-    def finalize_import(self, _):
+    def finalize_import(self, config):

         """ Do any required postprocessing to make the tokenizer data ready
             for use.
         """
         """ Do any required postprocessing to make the tokenizer data ready
             for use.
         """

+        with connect(self.dsn) as conn:
+            sqlp = SQLPreprocessor(conn, config)
+            sqlp.run_sql_file(conn, 'tokenizer/legacy_tokenizer_indices.sql')

 
 
     def update_sql_functions(self, config):
 
 
     def update_sql_functions(self, config):


@@ -84,33 +90,73 @@ class LegacyICUTokenizer(AbstractTokenizer):
     def check_database(self, config):
         """ Check that the tokenizer is set up correctly.
         """
     def check_database(self, config):
         """ Check that the tokenizer is set up correctly.
         """

+        # Will throw an error if there is an issue.

         self.init_from_project(config)
 
         self.init_from_project(config)
 

-        if self.term_normalization is None:
-            return "Configuration for tokenizer 'icu' are missing."
-
-        return None
-

 
     def update_statistics(self):
         """ Recompute frequencies for all name words.
         """
         with connect(self.dsn) as conn:
 
     def update_statistics(self):
         """ Recompute frequencies for all name words.
         """
         with connect(self.dsn) as conn:

-            with conn.cursor() as cur:
-                cur.drop_table("word_frequencies")
-                LOG.info("Computing word frequencies")
-                cur.execute("""CREATE TEMP TABLE word_frequencies AS
-                                 SELECT unnest(name_vector) as id, count(*)
-                                 FROM search_name GROUP BY id""")
-                cur.execute("CREATE INDEX ON word_frequencies(id)")
-                LOG.info("Update word table with recomputed frequencies")
-                cur.execute("""UPDATE word
-                               SET info = info || jsonb_build_object('count', count)
-                               FROM word_frequencies WHERE word_id = id""")
-                cur.drop_table("word_frequencies")
+            if conn.table_exists('search_name'):
+                with conn.cursor() as cur:
+                    cur.drop_table("word_frequencies")
+                    LOG.info("Computing word frequencies")
+                    cur.execute("""CREATE TEMP TABLE word_frequencies AS
+                                     SELECT unnest(name_vector) as id, count(*)
+                                     FROM search_name GROUP BY id""")
+                    cur.execute("CREATE INDEX ON word_frequencies(id)")
+                    LOG.info("Update word table with recomputed frequencies")
+                    cur.execute("""UPDATE word
+                                   SET info = info || jsonb_build_object('count', count)
+                                   FROM word_frequencies WHERE word_id = id""")
+                    cur.drop_table("word_frequencies")

             conn.commit()
 
 
             conn.commit()
 
 

+    def _cleanup_housenumbers(self):
+        """ Remove unused house numbers.
+        """
+        with connect(self.dsn) as conn:
+            if not conn.table_exists('search_name'):
+                return
+            with conn.cursor(name="hnr_counter") as cur:
+                cur.execute("""SELECT DISTINCT word_id, coalesce(info->>'lookup', word_token)
+                               FROM word
+                               WHERE type = 'H'
+                                 AND NOT EXISTS(SELECT * FROM search_name
+                                                WHERE ARRAY[word.word_id] && name_vector)
+                                 AND (char_length(coalesce(word, word_token)) > 6
+                                      OR coalesce(word, word_token) not similar to '\\d+')
+                            """)
+                candidates = {token: wid for wid, token in cur}
+            with conn.cursor(name="hnr_counter") as cur:
+                cur.execute("""SELECT housenumber FROM placex
+                               WHERE housenumber is not null
+                                     AND (char_length(housenumber) > 6
+                                          OR housenumber not similar to '\\d+')
+                            """)
+                for row in cur:
+                    for hnr in row[0].split(';'):
+                        candidates.pop(hnr, None)
+            LOG.info("There are %s outdated housenumbers.", len(candidates))
+            LOG.debug("Outdated housenumbers: %s", candidates.keys())
+            if candidates:
+                with conn.cursor() as cur:
+                    cur.execute("""DELETE FROM word WHERE word_id = any(%s)""",
+                                (list(candidates.values()), ))
+                conn.commit()
+
+
+
+    def update_word_tokens(self):
+        """ Remove unused tokens.
+        """
+        LOG.warning("Cleaning up housenumber tokens.")
+        self._cleanup_housenumbers()
+        LOG.warning("Tokenizer house-keeping done.")
+
+

     def name_analyzer(self):
         """ Create a new analyzer for tokenizing names and queries
             using this tokinzer. Analyzers are context managers and should
     def name_analyzer(self):
         """ Create a new analyzer for tokenizing names and queries
             using this tokinzer. Analyzers are context managers and should


@@ -130,16 +176,18 @@ class LegacyICUTokenizer(AbstractTokenizer):
                                      self.loader.make_token_analysis())
 
 
                                      self.loader.make_token_analysis())
 
 

-    def _install_php(self, phpdir):
+    def _install_php(self, phpdir, overwrite=True):

         """ Install the php script for the tokenizer.
         """
         php_file = self.data_dir / "tokenizer.php"
         """ Install the php script for the tokenizer.
         """
         php_file = self.data_dir / "tokenizer.php"

-        php_file.write_text(dedent(f"""\
-            <?php
-            @define('CONST_Max_Word_Frequency', 10000000);
-            @define('CONST_Term_Normalization_Rules', "{self.term_normalization}");
-            @define('CONST_Transliteration', "{self.loader.get_search_rules()}");
-            require_once('{phpdir}/tokenizer/icu_tokenizer.php');"""))
+
+        if not php_file.exists() or overwrite:
+            php_file.write_text(dedent(f"""\
+                <?php
+                @define('CONST_Max_Word_Frequency', 10000000);
+                @define('CONST_Term_Normalization_Rules', "{self.loader.normalization_rules}");
+                @define('CONST_Transliteration', "{self.loader.get_search_rules()}");
+                require_once('{phpdir}/tokenizer/icu_tokenizer.php');"""), encoding='utf-8')

 
 
     def _save_config(self):
 
 
     def _save_config(self):


@@ -148,7 +196,6 @@ class LegacyICUTokenizer(AbstractTokenizer):
         """
         with connect(self.dsn) as conn:
             self.loader.save_config_to_db(conn)
         """
         with connect(self.dsn) as conn:
             self.loader.save_config_to_db(conn)

-            set_property(conn, DBCFG_TERM_NORMALIZATION, self.term_normalization)

 
 
     def _init_db_tables(self, config):
 
 
     def _init_db_tables(self, config):


@@ -231,8 +278,7 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
                + [(k, v, part_ids.get(v, None)) for k, v in partial_tokens.items()]
 
 
                + [(k, v, part_ids.get(v, None)) for k, v in partial_tokens.items()]
 
 

-    @staticmethod
-    def normalize_postcode(postcode):
+    def normalize_postcode(self, postcode):

         """ Convert the postcode to a standardized form.
 
             This function must yield exactly the same result as the SQL function
         """ Convert the postcode to a standardized form.
 
             This function must yield exactly the same result as the SQL function


@@ -241,13 +287,6 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
         return postcode.strip().upper()
 
 
         return postcode.strip().upper()
 
 

-    def _make_standard_hnr(self, hnr):
-        """ Create a normalised version of a housenumber.
-
-            This function takes minor shortcuts on transliteration.
-        """
-        return self._search_normalized(hnr)
-

     def update_postcodes_from_db(self):
         """ Update postcode tokens in the word table from the location_postcode
             table.
     def update_postcodes_from_db(self):
         """ Update postcode tokens in the word table from the location_postcode
             table.


@@ -349,17 +388,18 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
 
 
     def add_country_names(self, country_code, names):
 
 
     def add_country_names(self, country_code, names):

-        """ Add names for the given country to the search index.
+        """ Add default names for the given country to the search index.

         """
         # Make sure any name preprocessing for country names applies.
         info = PlaceInfo({'name': names, 'country_code': country_code,
                           'rank_address': 4, 'class': 'boundary',
                           'type': 'administrative'})
         self._add_country_full_names(country_code,
         """
         # Make sure any name preprocessing for country names applies.
         info = PlaceInfo({'name': names, 'country_code': country_code,
                           'rank_address': 4, 'class': 'boundary',
                           'type': 'administrative'})
         self._add_country_full_names(country_code,

-                                     self.sanitizer.process_names(info)[0])
+                                     self.sanitizer.process_names(info)[0],
+                                     internal=True)

 
 
 
 

-    def _add_country_full_names(self, country_code, names):
+    def _add_country_full_names(self, country_code, names, internal=False):

         """ Add names for the given country from an already sanitized
             name list.
         """
         """ Add names for the given country from an already sanitized
             name list.
         """


@@ -371,21 +411,41 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
 
         with self.conn.cursor() as cur:
             # Get existing names
 
         with self.conn.cursor() as cur:
             # Get existing names

-            cur.execute("""SELECT word_token FROM word
-                            WHERE type = 'C' and word = %s""",
+            cur.execute("""SELECT word_token, coalesce(info ? 'internal', false) as is_internal
+                             FROM word
+                             WHERE type = 'C' and word = %s""",

                         (country_code, ))
                         (country_code, ))

-            word_tokens.difference_update((t[0] for t in cur))
+            existing_tokens = {True: set(), False: set()} # internal/external names
+            for word in cur:
+                existing_tokens[word[1]].add(word[0])
+
+            # Delete names that no longer exist.
+            gone_tokens = existing_tokens[internal] - word_tokens
+            if internal:
+                gone_tokens.update(existing_tokens[False] & word_tokens)
+            if gone_tokens:
+                cur.execute("""DELETE FROM word
+                               USING unnest(%s) as token
+                               WHERE type = 'C' and word = %s
+                                     and word_token = token""",
+                            (list(gone_tokens), country_code))

 
             # Only add those names that are not yet in the list.
 
             # Only add those names that are not yet in the list.

-            if word_tokens:
-                cur.execute("""INSERT INTO word (word_token, type, word)
-                               (SELECT token, 'C', %s
-                                FROM unnest(%s) as token)
-                            """, (country_code, list(word_tokens)))
-
-            # No names are deleted at the moment.
-            # If deletion is made possible, then the static names from the
-            # initial 'country_name' table should be kept.
+            new_tokens = word_tokens - existing_tokens[True]
+            if not internal:
+                new_tokens -= existing_tokens[False]
+            if new_tokens:
+                if internal:
+                    sql = """INSERT INTO word (word_token, type, word, info)
+                               (SELECT token, 'C', %s, '{"internal": "yes"}'
+                                  FROM unnest(%s) as token)
+                           """
+                else:
+                    sql = """INSERT INTO word (word_token, type, word)
+                                   (SELECT token, 'C', %s
+                                    FROM unnest(%s) as token)
+                          """
+                cur.execute(sql, (country_code, list(new_tokens)))

 
 
     def process_place(self, place):
 
 
     def process_place(self, place):


@@ -394,14 +454,12 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
             Returns a JSON-serializable structure that will be handed into
             the database via the token_info field.
         """
             Returns a JSON-serializable structure that will be handed into
             the database via the token_info field.
         """

-        token_info = _TokenInfo(self._cache)
+        token_info = _TokenInfo()

 
         names, address = self.sanitizer.process_names(place)
 
         if names:
 
         names, address = self.sanitizer.process_names(place)
 
         if names:

-            fulls, partials = self._compute_name_tokens(names)
-
-            token_info.add_names(fulls, partials)
+            token_info.set_names(*self._compute_name_tokens(names))

 
             if place.is_country():
                 self._add_country_full_names(place.country_code, names)
 
             if place.is_country():
                 self._add_country_full_names(place.country_code, names)


@@ -409,31 +467,59 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
         if address:
             self._process_place_address(token_info, address)
 
         if address:
             self._process_place_address(token_info, address)
 

-        return token_info.data
+        return token_info.to_dict()

 
 
     def _process_place_address(self, token_info, address):
 
 
     def _process_place_address(self, token_info, address):

-        hnrs = []
-        addr_terms = []

         for item in address:
             if item.kind == 'postcode':
                 self._add_postcode(item.name)
         for item in address:
             if item.kind == 'postcode':
                 self._add_postcode(item.name)

-            elif item.kind in ('housenumber', 'streetnumber', 'conscriptionnumber'):
-                hnrs.append(item.name)
+            elif item.kind == 'housenumber':
+                token_info.add_housenumber(*self._compute_housenumber_token(item))

             elif item.kind == 'street':
             elif item.kind == 'street':

-                token_info.add_street(self._compute_partial_tokens(item.name))
+                token_info.add_street(self._retrieve_full_tokens(item.name))

             elif item.kind == 'place':
             elif item.kind == 'place':

-                token_info.add_place(self._compute_partial_tokens(item.name))
-            elif not item.kind.startswith('_') and \
+                if not item.suffix:
+                    token_info.add_place(self._compute_partial_tokens(item.name))
+            elif not item.kind.startswith('_') and not item.suffix and \

                  item.kind not in ('country', 'full'):
                  item.kind not in ('country', 'full'):

-                addr_terms.append((item.kind, self._compute_partial_tokens(item.name)))
+                token_info.add_address_term(item.kind, self._compute_partial_tokens(item.name))
+
+
+    def _compute_housenumber_token(self, hnr):
+        """ Normalize the housenumber and return the word token and the
+            canonical form.
+        """
+        analyzer = self.token_analysis.analysis.get('@housenumber')
+        result = None, None

 
 

-        if hnrs:
-            hnrs = self._split_housenumbers(hnrs)
-            token_info.add_housenumbers(self.conn, [self._make_standard_hnr(n) for n in hnrs])
+        if analyzer is None:
+            # When no custom analyzer is set, simply normalize and transliterate
+            norm_name = self._search_normalized(hnr.name)
+            if norm_name:
+                result = self._cache.housenumbers.get(norm_name, result)
+                if result[0] is None:
+                    with self.conn.cursor() as cur:
+                        cur.execute("SELECT getorcreate_hnr_id(%s)", (norm_name, ))
+                        result = cur.fetchone()[0], norm_name
+                        self._cache.housenumbers[norm_name] = result
+        else:
+            # Otherwise use the analyzer to determine the canonical name.
+            # Per convention we use the first variant as the 'lookup name', the
+            # name that gets saved in the housenumber field of the place.
+            norm_name = analyzer.normalize(hnr.name)
+            if norm_name:
+                result = self._cache.housenumbers.get(norm_name, result)
+                if result[0] is None:
+                    variants = analyzer.get_variants_ascii(norm_name)
+                    if variants:
+                        with self.conn.cursor() as cur:
+                            cur.execute("SELECT create_analyzed_hnr_id(%s, %s)",
+                                        (norm_name, list(variants)))
+                            result = cur.fetchone()[0], variants[0]
+                            self._cache.housenumbers[norm_name] = result

 
 

-        if addr_terms:
-            token_info.add_address_terms(addr_terms)
+        return result

 
 
     def _compute_partial_tokens(self, name):
 
 
     def _compute_partial_tokens(self, name):


@@ -464,6 +550,26 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
         return tokens
 
 
         return tokens
 
 

+    def _retrieve_full_tokens(self, name):
+        """ Get the full name token for the given name, if it exists.
+            The name is only retrived for the standard analyser.
+        """
+        norm_name = self._search_normalized(name)
+
+        # return cached if possible
+        if norm_name in self._cache.fulls:
+            return self._cache.fulls[norm_name]
+
+        with self.conn.cursor() as cur:
+            cur.execute("SELECT word_id FROM word WHERE word_token = %s and type = 'W'",
+                        (norm_name, ))
+            full = [row[0] for row in cur]
+
+        self._cache.fulls[norm_name] = full
+
+        return full
+
+

     def _compute_name_tokens(self, names):
         """ Computes the full name and partial name tokens for the given
             dictionary of names.
     def _compute_name_tokens(self, names):
         """ Computes the full name and partial name tokens for the given
             dictionary of names.


@@ -473,7 +579,8 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
 
         for name in names:
             analyzer_id = name.get_attr('analyzer')
 
         for name in names:
             analyzer_id = name.get_attr('analyzer')

-            norm_name = self._normalized(name.name)
+            analyzer = self.token_analysis.get_analyzer(analyzer_id)
+            norm_name = analyzer.normalize(name.name)

             if analyzer_id is None:
                 token_id = norm_name
             else:
             if analyzer_id is None:
                 token_id = norm_name
             else:


@@ -481,12 +588,12 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
 
             full, part = self._cache.names.get(token_id, (None, None))
             if full is None:
 
             full, part = self._cache.names.get(token_id, (None, None))
             if full is None:

-                variants = self.token_analysis.analysis[analyzer_id].get_variants_ascii(norm_name)
+                variants = analyzer.get_variants_ascii(norm_name)

                 if not variants:
                     continue
 
                 with self.conn.cursor() as cur:
                 if not variants:
                     continue
 
                 with self.conn.cursor() as cur:

-                    cur.execute("SELECT (getorcreate_full_word(%s, %s)).*",
+                    cur.execute("SELECT * FROM getorcreate_full_word(%s, %s)",

                                 (token_id, variants))
                     full, part = cur.fetchone()
 
                                 (token_id, variants))
                     full, part = cur.fetchone()
 


@@ -520,72 +627,79 @@ class LegacyICUNameAnalyzer(AbstractAnalyzer):
                 self._cache.postcodes.add(postcode)
 
 
                 self._cache.postcodes.add(postcode)
 
 

+class _TokenInfo:
+    """ Collect token information to be sent back to the database.
+    """
+    def __init__(self):
+        self.names = None
+        self.housenumbers = set()
+        self.housenumber_tokens = set()
+        self.street_tokens = set()
+        self.place_tokens = set()
+        self.address_tokens = {}
+
+

     @staticmethod
     @staticmethod

-    def _split_housenumbers(hnrs):
-        if len(hnrs) > 1 or ',' in hnrs[0] or ';' in hnrs[0]:
-            # split numbers if necessary
-            simple_list = []
-            for hnr in hnrs:
-                simple_list.extend((x.strip() for x in re.split(r'[;,]', hnr)))
-
-            if len(simple_list) > 1:
-                hnrs = list(set(simple_list))
-            else:
-                hnrs = simple_list
+    def _mk_array(tokens):
+        return f"{{{','.join((str(s) for s in tokens))}}}"

 
 

-        return hnrs

 
 

+    def to_dict(self):
+        """ Return the token information in database importable format.
+        """
+        out = {}

 
 

+        if self.names:
+            out['names'] = self.names

 
 

+        if self.housenumbers:
+            out['hnr'] = ';'.join(self.housenumbers)
+            out['hnr_tokens'] = self._mk_array(self.housenumber_tokens)

 
 

-class _TokenInfo:
-    """ Collect token information to be sent back to the database.
-    """
-    def __init__(self, cache):
-        self._cache = cache
-        self.data = {}
+        if self.street_tokens:
+            out['street'] = self._mk_array(self.street_tokens)

 
 

-    @staticmethod
-    def _mk_array(tokens):
-        return '{%s}' % ','.join((str(s) for s in tokens))
+        if self.place_tokens:
+            out['place'] = self._mk_array(self.place_tokens)

 
 

+        if self.address_tokens:
+            out['addr'] = self.address_tokens

 
 

-    def add_names(self, fulls, partials):
+        return out
+
+
+    def set_names(self, fulls, partials):

         """ Adds token information for the normalised names.
         """
         """ Adds token information for the normalised names.
         """

-        self.data['names'] = self._mk_array(itertools.chain(fulls, partials))
+        self.names = self._mk_array(itertools.chain(fulls, partials))

 
 
 
 

-    def add_housenumbers(self, conn, hnrs):
+    def add_housenumber(self, token, hnr):

         """ Extract housenumber information from a list of normalised
             housenumbers.
         """
         """ Extract housenumber information from a list of normalised
             housenumbers.
         """

-        self.data['hnr_tokens'] = self._mk_array(self._cache.get_hnr_tokens(conn, hnrs))
-        self.data['hnr'] = ';'.join(hnrs)
+        if token:
+            self.housenumbers.add(hnr)
+            self.housenumber_tokens.add(token)

 
 
     def add_street(self, tokens):
         """ Add addr:street match terms.
         """
 
 
     def add_street(self, tokens):
         """ Add addr:street match terms.
         """

-        if tokens:
-            self.data['street'] = self._mk_array(tokens)
+        self.street_tokens.update(tokens)

 
 
     def add_place(self, tokens):
         """ Add addr:place search and match terms.
         """
 
 
     def add_place(self, tokens):
         """ Add addr:place search and match terms.
         """

-        if tokens:
-            self.data['place'] = self._mk_array(tokens)
+        self.place_tokens.update(tokens)

 
 
 
 

-    def add_address_terms(self, terms):
+    def add_address_term(self, key, partials):

         """ Add additional address terms.
         """
         """ Add additional address terms.
         """

-        tokens = {key: self._mk_array(partials)
-                  for key, partials in terms if partials}
-
-        if tokens:
-            self.data['addr'] = tokens
+        if partials:
+            self.address_tokens[key] = self._mk_array(partials)

 
 
 class _TokenCache:
 
 
 class _TokenCache:


@@ -597,31 +711,6 @@ class _TokenCache:
     def __init__(self):
         self.names = {}
         self.partials = {}
     def __init__(self):
         self.names = {}
         self.partials = {}

+        self.fulls = {}

         self.postcodes = set()
         self.housenumbers = {}
         self.postcodes = set()
         self.housenumbers = {}

-
-
-    def get_hnr_tokens(self, conn, terms):
-        """ Get token ids for a list of housenumbers, looking them up in the
-            database if necessary. `terms` is an iterable of normalized
-            housenumbers.
-        """
-        tokens = []
-        askdb = []
-
-        for term in terms:
-            token = self.housenumbers.get(term)
-            if token is None:
-                askdb.append(term)
-            else:
-                tokens.append(token)
-
-        if askdb:
-            with conn.cursor() as cur:
-                cur.execute("SELECT nr, getorcreate_hnr_id(nr) FROM unnest(%s) as nr",
-                            (askdb, ))
-                for term, tid in cur:
-                    self.housenumbers[term] = tid
-                    tokens.append(tid)
-
-        return tokens