Files
Nominatim/nominatim/tokenizer/icu_tokenizer.py
Sarah Hoffmann ec7184c533 icu: no longer precompute terms
The ICU analyzer no longer drops frequent partials, so it is no
longer necessary to know the frequencies in advance.
2021-10-19 11:52:28 +02:00

628 lines
22 KiB
Python

"""
Tokenizer implementing normalisation as used before Nominatim 4 but using
libICU instead of the PostgreSQL module.
"""
import itertools
import json
import logging
import re
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.tokenizer.icu_rule_loader import ICURuleLoader
from nominatim.tokenizer.base import AbstractAnalyzer, AbstractTokenizer
DBCFG_TERM_NORMALIZATION = "tokenizer_term_normalization"
LOG = logging.getLogger()
def create(dsn, data_dir):
""" Create a new instance of the tokenizer provided by this module.
"""
return LegacyICUTokenizer(dsn, data_dir)
class LegacyICUTokenizer(AbstractTokenizer):
""" This tokenizer uses libICU to covert names and queries to ASCII.
Otherwise it uses the same algorithms and data structures as the
normalization routines in Nominatim 3.
"""
def __init__(self, dsn, data_dir):
self.dsn = dsn
self.data_dir = data_dir
self.loader = None
self.term_normalization = None
def init_new_db(self, config, init_db=True):
""" Set up a new tokenizer for the database.
This copies all necessary data in the project directory to make
sure the tokenizer remains stable even over updates.
"""
self.loader = ICURuleLoader(config)
self.term_normalization = config.TERM_NORMALIZATION
self._install_php(config.lib_dir.php)
self._save_config()
if init_db:
self.update_sql_functions(config)
self._init_db_tables(config)
def init_from_project(self, config):
""" Initialise the tokenizer from the project directory.
"""
self.loader = ICURuleLoader(config)
with connect(self.dsn) as conn:
self.loader.load_config_from_db(conn)
self.term_normalization = get_property(conn, DBCFG_TERM_NORMALIZATION)
def finalize_import(self, _):
""" Do any required postprocessing to make the tokenizer data ready
for use.
"""
def update_sql_functions(self, config):
""" Reimport the SQL functions for this tokenizer.
"""
with connect(self.dsn) as conn:
sqlp = SQLPreprocessor(conn, config)
sqlp.run_sql_file(conn, 'tokenizer/icu_tokenizer.sql')
def check_database(self, config):
""" Check that the tokenizer is set up correctly.
"""
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:
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()
def name_analyzer(self):
""" Create a new analyzer for tokenizing names and queries
using this tokinzer. Analyzers are context managers and should
be used accordingly:
```
with tokenizer.name_analyzer() as analyzer:
analyser.tokenize()
```
When used outside the with construct, the caller must ensure to
call the close() function before destructing the analyzer.
Analyzers are not thread-safe. You need to instantiate one per thread.
"""
return LegacyICUNameAnalyzer(self.dsn, self.loader.make_sanitizer(),
self.loader.make_token_analysis())
def _install_php(self, phpdir):
""" 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');"""))
def _save_config(self):
""" Save the configuration that needs to remain stable for the given
database as database properties.
"""
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):
""" Set up the word table and fill it with pre-computed word
frequencies.
"""
with connect(self.dsn) as conn:
sqlp = SQLPreprocessor(conn, config)
sqlp.run_sql_file(conn, 'tokenizer/icu_tokenizer_tables.sql')
conn.commit()
class LegacyICUNameAnalyzer(AbstractAnalyzer):
""" The legacy analyzer uses the ICU library for splitting names.
Each instance opens a connection to the database to request the
normalization.
"""
def __init__(self, dsn, sanitizer, token_analysis):
self.conn = connect(dsn).connection
self.conn.autocommit = True
self.sanitizer = sanitizer
self.token_analysis = token_analysis
self._cache = _TokenCache()
def close(self):
""" Free all resources used by the analyzer.
"""
if self.conn:
self.conn.close()
self.conn = None
def _search_normalized(self, name):
""" Return the search token transliteration of the given name.
"""
return self.token_analysis.search.transliterate(name).strip()
def _normalized(self, name):
""" Return the normalized version of the given name with all
non-relevant information removed.
"""
return self.token_analysis.normalizer.transliterate(name).strip()
def get_word_token_info(self, words):
""" Return token information for the given list of words.
If a word starts with # it is assumed to be a full name
otherwise is a partial name.
The function returns a list of tuples with
(original word, word token, word id).
The function is used for testing and debugging only
and not necessarily efficient.
"""
full_tokens = {}
partial_tokens = {}
for word in words:
if word.startswith('#'):
full_tokens[word] = self._search_normalized(word[1:])
else:
partial_tokens[word] = self._search_normalized(word)
with self.conn.cursor() as cur:
cur.execute("""SELECT word_token, word_id
FROM word WHERE word_token = ANY(%s) and type = 'W'
""", (list(full_tokens.values()),))
full_ids = {r[0]: r[1] for r in cur}
cur.execute("""SELECT word_token, word_id
FROM word WHERE word_token = ANY(%s) and type = 'w'""",
(list(partial_tokens.values()),))
part_ids = {r[0]: r[1] for r in cur}
return [(k, v, full_ids.get(v, None)) for k, v in full_tokens.items()] \
+ [(k, v, part_ids.get(v, None)) for k, v in partial_tokens.items()]
@staticmethod
def normalize_postcode(postcode):
""" Convert the postcode to a standardized form.
This function must yield exactly the same result as the SQL function
'token_normalized_postcode()'.
"""
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.
"""
to_delete = []
with self.conn.cursor() as cur:
# This finds us the rows in location_postcode and word that are
# missing in the other table.
cur.execute("""SELECT * FROM
(SELECT pc, word FROM
(SELECT distinct(postcode) as pc FROM location_postcode) p
FULL JOIN
(SELECT word FROM word WHERE type = 'P') w
ON pc = word) x
WHERE pc is null or word is null""")
with CopyBuffer() as copystr:
for postcode, word in cur:
if postcode is None:
to_delete.append(word)
else:
copystr.add(self._search_normalized(postcode),
'P', postcode)
if to_delete:
cur.execute("""DELETE FROM WORD
WHERE type ='P' and word = any(%s)
""", (to_delete, ))
copystr.copy_out(cur, 'word',
columns=['word_token', 'type', 'word'])
def update_special_phrases(self, phrases, should_replace):
""" Replace the search index for special phrases with the new phrases.
If `should_replace` is True, then the previous set of will be
completely replaced. Otherwise the phrases are added to the
already existing ones.
"""
norm_phrases = set(((self._normalized(p[0]), p[1], p[2], p[3])
for p in phrases))
with self.conn.cursor() as cur:
# Get the old phrases.
existing_phrases = set()
cur.execute("SELECT word, info FROM word WHERE type = 'S'")
for word, info in cur:
existing_phrases.add((word, info['class'], info['type'],
info.get('op') or '-'))
added = self._add_special_phrases(cur, norm_phrases, existing_phrases)
if should_replace:
deleted = self._remove_special_phrases(cur, norm_phrases,
existing_phrases)
else:
deleted = 0
LOG.info("Total phrases: %s. Added: %s. Deleted: %s",
len(norm_phrases), added, deleted)
def _add_special_phrases(self, cursor, new_phrases, existing_phrases):
""" Add all phrases to the database that are not yet there.
"""
to_add = new_phrases - existing_phrases
added = 0
with CopyBuffer() as copystr:
for word, cls, typ, oper in to_add:
term = self._search_normalized(word)
if term:
copystr.add(term, 'S', word,
json.dumps({'class': cls, 'type': typ,
'op': oper if oper in ('in', 'near') else None}))
added += 1
copystr.copy_out(cursor, 'word',
columns=['word_token', 'type', 'word', 'info'])
return added
@staticmethod
def _remove_special_phrases(cursor, new_phrases, existing_phrases):
""" Remove all phrases from the databse that are no longer in the
new phrase list.
"""
to_delete = existing_phrases - new_phrases
if to_delete:
cursor.execute_values(
""" DELETE FROM word USING (VALUES %s) as v(name, in_class, in_type, op)
WHERE type = 'S' and word = name
and info->>'class' = in_class and info->>'type' = in_type
and ((op = '-' and info->>'op' is null) or op = info->>'op')
""", to_delete)
return len(to_delete)
def add_country_names(self, country_code, names):
""" Add 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,
self.sanitizer.process_names(info)[0])
def _add_country_full_names(self, country_code, names):
""" Add names for the given country from an already sanitized
name list.
"""
word_tokens = set()
for name in names:
norm_name = self._search_normalized(name.name)
if norm_name:
word_tokens.add(norm_name)
with self.conn.cursor() as cur:
# Get existing names
cur.execute("""SELECT word_token FROM word
WHERE type = 'C' and word = %s""",
(country_code, ))
word_tokens.difference_update((t[0] for t in cur))
# 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.
def process_place(self, place):
""" Determine tokenizer information about the given place.
Returns a JSON-serializable structure that will be handed into
the database via the token_info field.
"""
token_info = _TokenInfo(self._cache)
names, address = self.sanitizer.process_names(place)
if names:
fulls, partials = self._compute_name_tokens(names)
token_info.add_names(fulls, partials)
if place.is_country():
self._add_country_full_names(place.country_code, names)
if address:
self._process_place_address(token_info, address)
return token_info.data
def _process_place_address(self, token_info, address):
hnrs = []
addr_terms = []
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 == 'street':
token_info.add_street(self._compute_partial_tokens(item.name))
elif item.kind == 'place':
token_info.add_place(self._compute_partial_tokens(item.name))
elif not item.kind.startswith('_') and \
item.kind not in ('country', 'full'):
addr_terms.append((item.kind, self._compute_partial_tokens(item.name)))
if hnrs:
hnrs = self._split_housenumbers(hnrs)
token_info.add_housenumbers(self.conn, [self._make_standard_hnr(n) for n in hnrs])
if addr_terms:
token_info.add_address_terms(addr_terms)
def _compute_partial_tokens(self, name):
""" Normalize the given term, split it into partial words and return
then token list for them.
"""
norm_name = self._search_normalized(name)
tokens = []
need_lookup = []
for partial in norm_name.split():
token = self._cache.partials.get(partial)
if token:
tokens.append(token)
else:
need_lookup.append(partial)
if need_lookup:
with self.conn.cursor() as cur:
cur.execute("""SELECT word, getorcreate_partial_word(word)
FROM unnest(%s) word""",
(need_lookup, ))
for partial, token in cur:
tokens.append(token)
self._cache.partials[partial] = token
return tokens
def _compute_name_tokens(self, names):
""" Computes the full name and partial name tokens for the given
dictionary of names.
"""
full_tokens = set()
partial_tokens = set()
for name in names:
analyzer_id = name.get_attr('analyzer')
norm_name = self._normalized(name.name)
if analyzer_id is None:
token_id = norm_name
else:
token_id = f'{norm_name}@{analyzer_id}'
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)
if not variants:
continue
with self.conn.cursor() as cur:
cur.execute("SELECT (getorcreate_full_word(%s, %s)).*",
(token_id, variants))
full, part = cur.fetchone()
self._cache.names[token_id] = (full, part)
full_tokens.add(full)
partial_tokens.update(part)
return full_tokens, partial_tokens
def _add_postcode(self, postcode):
""" Make sure the normalized postcode is present in the word table.
"""
if re.search(r'[:,;]', postcode) is None:
postcode = self.normalize_postcode(postcode)
if postcode not in self._cache.postcodes:
term = self._search_normalized(postcode)
if not term:
return
with self.conn.cursor() as cur:
# no word_id needed for postcodes
cur.execute("""INSERT INTO word (word_token, type, word)
(SELECT %s, 'P', pc FROM (VALUES (%s)) as v(pc)
WHERE NOT EXISTS
(SELECT * FROM word
WHERE type = 'P' and word = pc))
""", (term, postcode))
self._cache.postcodes.add(postcode)
@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
return hnrs
class _TokenInfo:
""" Collect token information to be sent back to the database.
"""
def __init__(self, cache):
self._cache = cache
self.data = {}
@staticmethod
def _mk_array(tokens):
return '{%s}' % ','.join((str(s) for s in tokens))
def add_names(self, fulls, partials):
""" Adds token information for the normalised names.
"""
self.data['names'] = self._mk_array(itertools.chain(fulls, partials))
def add_housenumbers(self, conn, hnrs):
""" 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)
def add_street(self, tokens):
""" Add addr:street match terms.
"""
if tokens:
self.data['street'] = self._mk_array(tokens)
def add_place(self, tokens):
""" Add addr:place search and match terms.
"""
if tokens:
self.data['place'] = self._mk_array(tokens)
def add_address_terms(self, terms):
""" Add additional address terms.
"""
tokens = {key: self._mk_array(partials)
for key, partials in terms if partials}
if tokens:
self.data['addr'] = tokens
class _TokenCache:
""" Cache for token information to avoid repeated database queries.
This cache is not thread-safe and needs to be instantiated per
analyzer.
"""
def __init__(self):
self.names = {}
self.partials = {}
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