Files
Nominatim/src/nominatim_api/search/db_search_builder.py
Sarah Hoffmann 499110f549 add SOFT_PHRASE break and enable parsing
Also enables parsing of PART breaks.
2025-01-06 17:10:24 +01:00

441 lines
20 KiB
Python

# SPDX-License-Identifier: GPL-3.0-or-later
#
# This file is part of Nominatim. (https://nominatim.org)
#
# Copyright (C) 2024 by the Nominatim developer community.
# For a full list of authors see the git log.
"""
Conversion from token assignment to an abstract DB search.
"""
from typing import Optional, List, Tuple, Iterator, Dict
import heapq
from ..types import SearchDetails, DataLayer
from .query import QueryStruct, Token, TokenType, TokenRange, BreakType
from .token_assignment import TokenAssignment
from . import db_search_fields as dbf
from . import db_searches as dbs
from . import db_search_lookups as lookups
def wrap_near_search(categories: List[Tuple[str, str]],
search: dbs.AbstractSearch) -> dbs.NearSearch:
""" Create a new search that wraps the given search in a search
for near places of the given category.
"""
return dbs.NearSearch(penalty=search.penalty,
categories=dbf.WeightedCategories(categories,
[0.0] * len(categories)),
search=search)
def build_poi_search(category: List[Tuple[str, str]],
countries: Optional[List[str]]) -> dbs.PoiSearch:
""" Create a new search for places by the given category, possibly
constraint to the given countries.
"""
if countries:
ccs = dbf.WeightedStrings(countries, [0.0] * len(countries))
else:
ccs = dbf.WeightedStrings([], [])
class _PoiData(dbf.SearchData):
penalty = 0.0
qualifiers = dbf.WeightedCategories(category, [0.0] * len(category))
countries = ccs
return dbs.PoiSearch(_PoiData())
class SearchBuilder:
""" Build the abstract search queries from token assignments.
"""
def __init__(self, query: QueryStruct, details: SearchDetails) -> None:
self.query = query
self.details = details
@property
def configured_for_country(self) -> bool:
""" Return true if the search details are configured to
allow countries in the result.
"""
return self.details.min_rank <= 4 and self.details.max_rank >= 4 \
and self.details.layer_enabled(DataLayer.ADDRESS)
@property
def configured_for_postcode(self) -> bool:
""" Return true if the search details are configured to
allow postcodes in the result.
"""
return self.details.min_rank <= 5 and self.details.max_rank >= 11\
and self.details.layer_enabled(DataLayer.ADDRESS)
@property
def configured_for_housenumbers(self) -> bool:
""" Return true if the search details are configured to
allow addresses in the result.
"""
return self.details.max_rank >= 30 \
and self.details.layer_enabled(DataLayer.ADDRESS)
def build(self, assignment: TokenAssignment) -> Iterator[dbs.AbstractSearch]:
""" Yield all possible abstract searches for the given token assignment.
"""
sdata = self.get_search_data(assignment)
if sdata is None:
return
near_items = self.get_near_items(assignment)
if near_items is not None and not near_items:
return # impossible combination of near items and category parameter
if assignment.name is None:
if near_items and not sdata.postcodes:
sdata.qualifiers = near_items
near_items = None
builder = self.build_poi_search(sdata)
elif assignment.housenumber:
hnr_tokens = self.query.get_tokens(assignment.housenumber,
TokenType.HOUSENUMBER)
builder = self.build_housenumber_search(sdata, hnr_tokens, assignment.address)
else:
builder = self.build_special_search(sdata, assignment.address,
bool(near_items))
else:
builder = self.build_name_search(sdata, assignment.name, assignment.address,
bool(near_items))
if near_items:
penalty = min(near_items.penalties)
near_items.penalties = [p - penalty for p in near_items.penalties]
for search in builder:
search_penalty = search.penalty
search.penalty = 0.0
yield dbs.NearSearch(penalty + assignment.penalty + search_penalty,
near_items, search)
else:
for search in builder:
search.penalty += assignment.penalty
yield search
def build_poi_search(self, sdata: dbf.SearchData) -> Iterator[dbs.AbstractSearch]:
""" Build abstract search query for a simple category search.
This kind of search requires an additional geographic constraint.
"""
if not sdata.housenumbers \
and ((self.details.viewbox and self.details.bounded_viewbox) or self.details.near):
yield dbs.PoiSearch(sdata)
def build_special_search(self, sdata: dbf.SearchData,
address: List[TokenRange],
is_category: bool) -> Iterator[dbs.AbstractSearch]:
""" Build abstract search queries for searches that do not involve
a named place.
"""
if sdata.qualifiers:
# No special searches over qualifiers supported.
return
if sdata.countries and not address and not sdata.postcodes \
and self.configured_for_country:
yield dbs.CountrySearch(sdata)
if sdata.postcodes and (is_category or self.configured_for_postcode):
penalty = 0.0 if sdata.countries else 0.1
if address:
sdata.lookups = [dbf.FieldLookup('nameaddress_vector',
[t.token for r in address
for t in self.query.get_partials_list(r)],
lookups.Restrict)]
penalty += 0.2
yield dbs.PostcodeSearch(penalty, sdata)
def build_housenumber_search(self, sdata: dbf.SearchData, hnrs: List[Token],
address: List[TokenRange]) -> Iterator[dbs.AbstractSearch]:
""" Build a simple address search for special entries where the
housenumber is the main name token.
"""
sdata.lookups = [dbf.FieldLookup('name_vector', [t.token for t in hnrs], lookups.LookupAny)]
expected_count = sum(t.count for t in hnrs)
partials = {t.token: t.addr_count for trange in address
for t in self.query.get_partials_list(trange)}
if not partials:
# can happen when none of the partials is indexed
return
if expected_count < 8000:
sdata.lookups.append(dbf.FieldLookup('nameaddress_vector',
list(partials), lookups.Restrict))
elif len(partials) != 1 or list(partials.values())[0] < 10000:
sdata.lookups.append(dbf.FieldLookup('nameaddress_vector',
list(partials), lookups.LookupAll))
else:
addr_fulls = [t.token for t
in self.query.get_tokens(address[0], TokenType.WORD)]
if len(addr_fulls) > 5:
return
sdata.lookups.append(
dbf.FieldLookup('nameaddress_vector', addr_fulls, lookups.LookupAny))
sdata.housenumbers = dbf.WeightedStrings([], [])
yield dbs.PlaceSearch(0.05, sdata, expected_count)
def build_name_search(self, sdata: dbf.SearchData,
name: TokenRange, address: List[TokenRange],
is_category: bool) -> Iterator[dbs.AbstractSearch]:
""" Build abstract search queries for simple name or address searches.
"""
if is_category or not sdata.housenumbers or self.configured_for_housenumbers:
ranking = self.get_name_ranking(name)
name_penalty = ranking.normalize_penalty()
if ranking.rankings:
sdata.rankings.append(ranking)
for penalty, count, lookup in self.yield_lookups(name, address):
sdata.lookups = lookup
yield dbs.PlaceSearch(penalty + name_penalty, sdata, count)
def yield_lookups(self, name: TokenRange, address: List[TokenRange]
) -> Iterator[Tuple[float, int, List[dbf.FieldLookup]]]:
""" Yield all variants how the given name and address should best
be searched for. This takes into account how frequent the terms
are and tries to find a lookup that optimizes index use.
"""
penalty = 0.0 # extra penalty
name_partials = {t.token: t for t in self.query.get_partials_list(name)}
addr_partials = [t for r in address for t in self.query.get_partials_list(r)]
addr_tokens = list({t.token for t in addr_partials})
exp_count = min(t.count for t in name_partials.values()) / (2**(len(name_partials) - 1))
if (len(name_partials) > 3 or exp_count < 8000):
yield penalty, exp_count, dbf.lookup_by_names(list(name_partials.keys()), addr_tokens)
return
addr_count = min(t.addr_count for t in addr_partials) if addr_partials else 30000
# Partial term to frequent. Try looking up by rare full names first.
name_fulls = self.query.get_tokens(name, TokenType.WORD)
if name_fulls:
fulls_count = sum(t.count for t in name_fulls)
if fulls_count < 50000 or addr_count < 30000:
yield penalty, fulls_count / (2**len(addr_tokens)), \
self.get_full_name_ranking(name_fulls, addr_partials,
fulls_count > 30000 / max(1, len(addr_tokens)))
# To catch remaining results, lookup by name and address
# We only do this if there is a reasonable number of results expected.
exp_count = exp_count / (2**len(addr_tokens)) if addr_tokens else exp_count
if exp_count < 10000 and addr_count < 20000:
penalty += 0.35 * max(1 if name_fulls else 0.1,
5 - len(name_partials) - len(addr_tokens))
yield penalty, exp_count, \
self.get_name_address_ranking(list(name_partials.keys()), addr_partials)
def get_name_address_ranking(self, name_tokens: List[int],
addr_partials: List[Token]) -> List[dbf.FieldLookup]:
""" Create a ranking expression looking up by name and address.
"""
lookup = [dbf.FieldLookup('name_vector', name_tokens, lookups.LookupAll)]
addr_restrict_tokens = []
addr_lookup_tokens = []
for t in addr_partials:
if t.addr_count > 20000:
addr_restrict_tokens.append(t.token)
else:
addr_lookup_tokens.append(t.token)
if addr_restrict_tokens:
lookup.append(dbf.FieldLookup('nameaddress_vector',
addr_restrict_tokens, lookups.Restrict))
if addr_lookup_tokens:
lookup.append(dbf.FieldLookup('nameaddress_vector',
addr_lookup_tokens, lookups.LookupAll))
return lookup
def get_full_name_ranking(self, name_fulls: List[Token], addr_partials: List[Token],
use_lookup: bool) -> List[dbf.FieldLookup]:
""" Create a ranking expression with full name terms and
additional address lookup. When 'use_lookup' is true, then
address lookups will use the index, when the occurrences are not
too many.
"""
# At this point drop unindexed partials from the address.
# This might yield wrong results, nothing we can do about that.
if use_lookup:
addr_restrict_tokens = []
addr_lookup_tokens = []
for t in addr_partials:
if t.addr_count > 20000:
addr_restrict_tokens.append(t.token)
else:
addr_lookup_tokens.append(t.token)
else:
addr_restrict_tokens = [t.token for t in addr_partials]
addr_lookup_tokens = []
return dbf.lookup_by_any_name([t.token for t in name_fulls],
addr_restrict_tokens, addr_lookup_tokens)
def get_name_ranking(self, trange: TokenRange,
db_field: str = 'name_vector') -> dbf.FieldRanking:
""" Create a ranking expression for a name term in the given range.
"""
name_fulls = self.query.get_tokens(trange, TokenType.WORD)
ranks = [dbf.RankedTokens(t.penalty, [t.token]) for t in name_fulls]
ranks.sort(key=lambda r: r.penalty)
# Fallback, sum of penalty for partials
name_partials = self.query.get_partials_list(trange)
default = sum(t.penalty for t in name_partials) + 0.2
return dbf.FieldRanking(db_field, default, ranks)
def get_addr_ranking(self, trange: TokenRange) -> dbf.FieldRanking:
""" Create a list of ranking expressions for an address term
for the given ranges.
"""
todo: List[Tuple[int, int, dbf.RankedTokens]] = []
heapq.heappush(todo, (0, trange.start, dbf.RankedTokens(0.0, [])))
ranks: List[dbf.RankedTokens] = []
while todo:
neglen, pos, rank = heapq.heappop(todo)
for tlist in self.query.nodes[pos].starting:
if tlist.ttype in (TokenType.PARTIAL, TokenType.WORD):
if tlist.end < trange.end:
chgpenalty = PENALTY_WORDCHANGE[self.query.nodes[tlist.end].btype]
if tlist.ttype == TokenType.PARTIAL:
penalty = rank.penalty + chgpenalty \
+ max(t.penalty for t in tlist.tokens)
heapq.heappush(todo, (neglen - 1, tlist.end,
dbf.RankedTokens(penalty, rank.tokens)))
else:
for t in tlist.tokens:
heapq.heappush(todo, (neglen - 1, tlist.end,
rank.with_token(t, chgpenalty)))
elif tlist.end == trange.end:
if tlist.ttype == TokenType.PARTIAL:
ranks.append(dbf.RankedTokens(rank.penalty
+ max(t.penalty for t in tlist.tokens),
rank.tokens))
else:
ranks.extend(rank.with_token(t, 0.0) for t in tlist.tokens)
if len(ranks) >= 10:
# Too many variants, bail out and only add
# Worst-case Fallback: sum of penalty of partials
name_partials = self.query.get_partials_list(trange)
default = sum(t.penalty for t in name_partials) + 0.2
ranks.append(dbf.RankedTokens(rank.penalty + default, []))
# Bail out of outer loop
todo.clear()
break
ranks.sort(key=lambda r: len(r.tokens))
default = ranks[0].penalty + 0.3
del ranks[0]
ranks.sort(key=lambda r: r.penalty)
return dbf.FieldRanking('nameaddress_vector', default, ranks)
def get_search_data(self, assignment: TokenAssignment) -> Optional[dbf.SearchData]:
""" Collect the tokens for the non-name search fields in the
assignment.
"""
sdata = dbf.SearchData()
sdata.penalty = assignment.penalty
if assignment.country:
tokens = self.get_country_tokens(assignment.country)
if not tokens:
return None
sdata.set_strings('countries', tokens)
elif self.details.countries:
sdata.countries = dbf.WeightedStrings(self.details.countries,
[0.0] * len(self.details.countries))
if assignment.housenumber:
sdata.set_strings('housenumbers',
self.query.get_tokens(assignment.housenumber,
TokenType.HOUSENUMBER))
if assignment.postcode:
sdata.set_strings('postcodes',
self.query.get_tokens(assignment.postcode,
TokenType.POSTCODE))
if assignment.qualifier:
tokens = self.get_qualifier_tokens(assignment.qualifier)
if not tokens:
return None
sdata.set_qualifiers(tokens)
elif self.details.categories:
sdata.qualifiers = dbf.WeightedCategories(self.details.categories,
[0.0] * len(self.details.categories))
if assignment.address:
if not assignment.name and assignment.housenumber:
# housenumber search: the first item needs to be handled like
# a name in ranking or penalties are not comparable with
# normal searches.
sdata.set_ranking([self.get_name_ranking(assignment.address[0],
db_field='nameaddress_vector')]
+ [self.get_addr_ranking(r) for r in assignment.address[1:]])
else:
sdata.set_ranking([self.get_addr_ranking(r) for r in assignment.address])
else:
sdata.rankings = []
return sdata
def get_country_tokens(self, trange: TokenRange) -> List[Token]:
""" Return the list of country tokens for the given range,
optionally filtered by the country list from the details
parameters.
"""
tokens = self.query.get_tokens(trange, TokenType.COUNTRY)
if self.details.countries:
tokens = [t for t in tokens if t.lookup_word in self.details.countries]
return tokens
def get_qualifier_tokens(self, trange: TokenRange) -> List[Token]:
""" Return the list of qualifier tokens for the given range,
optionally filtered by the qualifier list from the details
parameters.
"""
tokens = self.query.get_tokens(trange, TokenType.QUALIFIER)
if self.details.categories:
tokens = [t for t in tokens if t.get_category() in self.details.categories]
return tokens
def get_near_items(self, assignment: TokenAssignment) -> Optional[dbf.WeightedCategories]:
""" Collect tokens for near items search or use the categories
requested per parameter.
Returns None if no category search is requested.
"""
if assignment.near_item:
tokens: Dict[Tuple[str, str], float] = {}
for t in self.query.get_tokens(assignment.near_item, TokenType.NEAR_ITEM):
cat = t.get_category()
# The category of a near search will be that of near_item.
# Thus, if search is restricted to a category parameter,
# the two sets must intersect.
if (not self.details.categories or cat in self.details.categories)\
and t.penalty < tokens.get(cat, 1000.0):
tokens[cat] = t.penalty
return dbf.WeightedCategories(list(tokens.keys()), list(tokens.values()))
return None
PENALTY_WORDCHANGE = {
BreakType.START: 0.0,
BreakType.END: 0.0,
BreakType.PHRASE: 0.0,
BreakType.SOFT_PHRASE: 0.0,
BreakType.WORD: 0.1,
BreakType.PART: 0.2,
BreakType.TOKEN: 0.4
}