Merge pull request #3117 from lonvia/fix-assorted-search-errors

More improvements to the Python search algorithm

nominatim/api/search/db_search_builder.py

@@ -15,7 +15,6 @@
 from nominatim.api.search.token_assignment import TokenAssignment
 import nominatim.api.search.db_search_fields as dbf
 import nominatim.api.search.db_searches as dbs
-from nominatim.api.logging import log
 
 
 def wrap_near_search(categories: List[Tuple[str, str]],
@@ -156,13 +155,22 @@ def build_housenumber_search(self, sdata: dbf.SearchData, hnrs: List[Token],
         """ Build a simple address search for special entries where the
             housenumber is the main name token.
         """
-        partial_tokens: List[int] = []
-        for trange in address:
-            partial_tokens.extend(t.token for t in self.query.get_partials_list(trange))
+        sdata.lookups = [dbf.FieldLookup('name_vector', [t.token for t in hnrs], 'lookup_any')]
 
-        sdata.lookups = [dbf.FieldLookup('name_vector', [t.token for t in hnrs], 'lookup_any'),
-                         dbf.FieldLookup('nameaddress_vector', partial_tokens, 'lookup_all')
-                        ]
+        partials = [t for trange in address
+                       for t in self.query.get_partials_list(trange)]
+
+        if len(partials) != 1 or partials[0].count < 10000:
+            sdata.lookups.append(dbf.FieldLookup('nameaddress_vector',
+                                                 [t.token for t in partials], 'lookup_all'))
+        else:
+            sdata.lookups.append(
+                dbf.FieldLookup('nameaddress_vector',
+                                [t.token for t
+                                 in self.query.get_tokens(address[0], TokenType.WORD)],
+                                'lookup_any'))
+
+        sdata.housenumbers = dbf.WeightedStrings([], [])
         yield dbs.PlaceSearch(0.05, sdata, sum(t.count for t in hnrs))
 
 
@@ -187,69 +195,63 @@ def yield_lookups(self, name: TokenRange, address: List[TokenRange])\
             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 currently unused
-
+        penalty = 0.0 # extra penalty
         name_partials = self.query.get_partials_list(name)
-        exp_name_count = min(t.count for t in name_partials)
-        addr_partials = []
-        for trange in address:
-            addr_partials.extend(self.query.get_partials_list(trange))
+        name_tokens = [t.token for t in name_partials]
+
+        addr_partials = [t for r in address for t in self.query.get_partials_list(r)]
         addr_tokens = [t.token for t in addr_partials]
+
         partials_indexed = all(t.is_indexed for t in name_partials) \
                            and all(t.is_indexed for t in addr_partials)
+        exp_count = min(t.count for t in name_partials)
 
-        if (len(name_partials) > 3 or exp_name_count < 1000) and partials_indexed:
-            # Lookup by name partials, use address partials to restrict results.
-            lookup = [dbf.FieldLookup('name_vector',
-                                  [t.token for t in name_partials], 'lookup_all')]
-            if addr_tokens:
-                lookup.append(dbf.FieldLookup('nameaddress_vector', addr_tokens, 'restrict'))
-            yield penalty, exp_name_count, lookup
+        if (len(name_partials) > 3 or exp_count < 1000) and partials_indexed:
+            yield penalty, exp_count, dbf.lookup_by_names(name_tokens, addr_tokens)
             return
 
-        exp_addr_count = min(t.count for t in addr_partials) if addr_partials else exp_name_count
-        if exp_addr_count < 1000 and partials_indexed:
+        exp_count = min(exp_count, min(t.count for t in addr_partials)) \
+                    if addr_partials else exp_count
+        if exp_count < 1000 and partials_indexed:
             # Lookup by address partials and restrict results through name terms.
             # Give this a small penalty because lookups in the address index are
             # more expensive
-            yield penalty + exp_addr_count/5000, exp_addr_count,\
-                  [dbf.FieldLookup('name_vector', [t.token for t in name_partials], 'restrict'),
-                   dbf.FieldLookup('nameaddress_vector', addr_tokens, 'lookup_all')]
+            yield penalty + exp_count/5000, exp_count,\
+                  dbf.lookup_by_addr(name_tokens, addr_tokens)
             return
 
         # Partial term to frequent. Try looking up by rare full names first.
         name_fulls = self.query.get_tokens(name, TokenType.WORD)
-        rare_names = list(filter(lambda t: t.count < 1000, name_fulls))
+        rare_names = list(filter(lambda t: t.count < 10000, name_fulls))
         # At this point drop unindexed partials from the address.
         # This might yield wrong results, nothing we can do about that.
         if not partials_indexed:
             addr_tokens = [t.token for t in addr_partials if t.is_indexed]
-            log().var_dump('before', penalty)
             penalty += 1.2 * sum(t.penalty for t in addr_partials if not t.is_indexed)
-            log().var_dump('after', penalty)
         if rare_names:
             # Any of the full names applies with all of the partials from the address
-            lookup = [dbf.FieldLookup('name_vector', [t.token for t in rare_names], 'lookup_any')]
-            if addr_tokens:
-                lookup.append(dbf.FieldLookup('nameaddress_vector', addr_tokens, 'restrict'))
-            yield penalty, sum(t.count for t in rare_names), lookup
+            yield penalty, sum(t.count for t in rare_names),\
+                  dbf.lookup_by_any_name([t.token for t in rare_names], addr_tokens)
 
         # To catch remaining results, lookup by name and address
         # We only do this if there is a reasonable number of results expected.
-        if min(exp_name_count, exp_addr_count) < 10000:
+        if exp_count < 10000:
             if all(t.is_indexed for t in name_partials):
-                lookup = [dbf.FieldLookup('name_vector',
-                                          [t.token for t in name_partials], 'lookup_all')]
+                lookup = [dbf.FieldLookup('name_vector', name_tokens, 'lookup_all')]
             else:
                 # we don't have the partials, try with the non-rare names
-                non_rare_names = [t.token for t in name_fulls if t.count >= 1000]
+                non_rare_names = [t.token for t in name_fulls if t.count >= 10000]
                 if not non_rare_names:
                     return
                 lookup = [dbf.FieldLookup('name_vector', non_rare_names, 'lookup_any')]
             if addr_tokens:
                 lookup.append(dbf.FieldLookup('nameaddress_vector', addr_tokens, 'lookup_all'))
-            yield penalty + 0.1 * max(0, 5 - len(name_partials) - len(addr_tokens)),\
-                  min(exp_name_count, exp_addr_count), lookup
+            penalty += 0.1 * max(0, 5 - len(name_partials) - len(addr_tokens))
+            if len(rare_names) == len(name_fulls):
+                # if there already was a search for all full tokens,
+                # avoid this if anything has been found
+                penalty += 0.25
+            yield penalty, exp_count, lookup
 
 
     def get_name_ranking(self, trange: TokenRange) -> dbf.FieldRanking:

nominatim/api/search/db_search_fields.py

@@ -211,3 +211,34 @@ def set_ranking(self, rankings: List[FieldRanking]) -> None:
                 self.rankings.append(ranking)
             else:
                 self.penalty += ranking.default
+
+
+def lookup_by_names(name_tokens: List[int], addr_tokens: List[int]) -> List[FieldLookup]:
+    """ Create a lookup list where name tokens are looked up via index
+        and potential address tokens are used to restrict the search further.
+    """
+    lookup = [FieldLookup('name_vector', name_tokens, 'lookup_all')]
+    if addr_tokens:
+        lookup.append(FieldLookup('nameaddress_vector', addr_tokens, 'restrict'))
+
+    return lookup
+
+
+def lookup_by_any_name(name_tokens: List[int], addr_tokens: List[int]) -> List[FieldLookup]:
+    """ Create a lookup list where name tokens are looked up via index
+        and only one of the name tokens must be present.
+        Potential address tokens are used to restrict the search further.
+    """
+    lookup = [FieldLookup('name_vector', name_tokens, 'lookup_any')]
+    if addr_tokens:
+        lookup.append(FieldLookup('nameaddress_vector', addr_tokens, 'restrict'))
+
+    return lookup
+
+
+def lookup_by_addr(name_tokens: List[int], addr_tokens: List[int]) -> List[FieldLookup]:
+    """ Create a lookup list where address tokens are looked up via index
+        and the name tokens are only used to restrict the search further.
+    """
+    return [FieldLookup('name_vector', name_tokens, 'restrict'),
+            FieldLookup('nameaddress_vector', addr_tokens, 'lookup_all')]

nominatim/api/search/query.py

@@ -7,7 +7,7 @@
 """
 Datastructures for a tokenized query.
 """
-from typing import List, Tuple, Optional, NamedTuple, Iterator
+from typing import List, Tuple, Optional, Iterator
 from abc import ABC, abstractmethod
 import dataclasses
 import enum
@@ -107,13 +107,29 @@ def get_category(self) -> Tuple[str, str]:
             category objects.
         """
 
-
-class TokenRange(NamedTuple):
+@dataclasses.dataclass
+class TokenRange:
     """ Indexes of query nodes over which a token spans.
     """
     start: int
     end: int
 
+    def __lt__(self, other: 'TokenRange') -> bool:
+        return self.end <= other.start
+
+
+    def __le__(self, other: 'TokenRange') -> bool:
+        return NotImplemented
+
+
+    def __gt__(self, other: 'TokenRange') -> bool:
+        return self.start >= other.end
+
+
+    def __ge__(self, other: 'TokenRange') -> bool:
+        return NotImplemented
+
+
     def replace_start(self, new_start: int) -> 'TokenRange':
         """ Return a new token range with the new start.
         """

nominatim/api/search/token_assignment.py

@@ -257,6 +257,97 @@ def recheck_sequence(self) -> bool:
         return True
 
 
+    def _get_assignments_postcode(self, base: TokenAssignment,
+                                  query_len: int)  -> Iterator[TokenAssignment]:
+        """ Yield possible assignments of Postcode searches with an
+            address component.
+        """
+        assert base.postcode is not None
+
+        if (base.postcode.start == 0 and self.direction != -1)\
+           or (base.postcode.end == query_len and self.direction != 1):
+            log().comment('postcode search')
+            # <address>,<postcode> should give preference to address search
+            if base.postcode.start == 0:
+                penalty = self.penalty
+                self.direction = -1 # name searches are only possbile backwards
+            else:
+                penalty = self.penalty + 0.1
+                self.direction = 1 # name searches are only possbile forwards
+            yield dataclasses.replace(base, penalty=penalty)
+
+
+    def _get_assignments_address_forward(self, base: TokenAssignment,
+                                         query: qmod.QueryStruct) -> Iterator[TokenAssignment]:
+        """ Yield possible assignments of address searches with
+            left-to-right reading.
+        """
+        first = base.address[0]
+
+        log().comment('first word = name')
+        yield dataclasses.replace(base, penalty=self.penalty,
+                                  name=first, address=base.address[1:])
+
+        # To paraphrase:
+        #  * if another name term comes after the first one and before the
+        #    housenumber
+        #  * a qualifier comes after the name
+        #  * the containing phrase is strictly typed
+        if (base.housenumber and first.end < base.housenumber.start)\
+           or (base.qualifier and base.qualifier > first)\
+           or (query.nodes[first.start].ptype != qmod.PhraseType.NONE):
+            return
+
+        penalty = self.penalty
+
+        # Penalty for:
+        #  * <name>, <street>, <housenumber> , ...
+        #  * queries that are comma-separated
+        if (base.housenumber and base.housenumber > first) or len(query.source) > 1:
+            penalty += 0.25
+
+        for i in range(first.start + 1, first.end):
+            name, addr = first.split(i)
+            log().comment(f'split first word = name ({i - first.start})')
+            yield dataclasses.replace(base, name=name, address=[addr] + base.address[1:],
+                                      penalty=penalty + PENALTY_TOKENCHANGE[query.nodes[i].btype])
+
+
+    def _get_assignments_address_backward(self, base: TokenAssignment,
+                                          query: qmod.QueryStruct) -> Iterator[TokenAssignment]:
+        """ Yield possible assignments of address searches with
+            right-to-left reading.
+        """
+        last = base.address[-1]
+
+        if self.direction == -1 or len(base.address) > 1:
+            log().comment('last word = name')
+            yield dataclasses.replace(base, penalty=self.penalty,
+                                      name=last, address=base.address[:-1])
+
+        # To paraphrase:
+        #  * if another name term comes before the last one and after the
+        #    housenumber
+        #  * a qualifier comes before the name
+        #  * the containing phrase is strictly typed
+        if (base.housenumber and last.start > base.housenumber.end)\
+           or (base.qualifier and base.qualifier < last)\
+           or (query.nodes[last.start].ptype != qmod.PhraseType.NONE):
+            return
+
+        penalty = self.penalty
+        if base.housenumber and base.housenumber < last:
+            penalty += 0.4
+        if len(query.source) > 1:
+            penalty += 0.25
+
+        for i in range(last.start + 1, last.end):
+            addr, name = last.split(i)
+            log().comment(f'split last word = name ({i - last.start})')
+            yield dataclasses.replace(base, name=name, address=base.address[:-1] + [addr],
+                                      penalty=penalty + PENALTY_TOKENCHANGE[query.nodes[i].btype])
+
+
     def get_assignments(self, query: qmod.QueryStruct) -> Iterator[TokenAssignment]:
         """ Yield possible assignments for the current sequence.
 
@@ -265,17 +356,13 @@ def get_assignments(self, query: qmod.QueryStruct) -> Iterator[TokenAssignment]:
         """
         base = TokenAssignment.from_ranges(self.seq)
 
+        num_addr_tokens = sum(t.end - t.start for t in base.address)
+        if num_addr_tokens > 50:
+            return
+
         # Postcode search (postcode-only search is covered in next case)
         if base.postcode is not None and base.address:
-            if (base.postcode.start == 0 and self.direction != -1)\
-               or (base.postcode.end == query.num_token_slots() and self.direction != 1):
-                log().comment('postcode search')
-                # <address>,<postcode> should give preference to address search
-                if base.postcode.start == 0:
-                    penalty = self.penalty
-                else:
-                    penalty = self.penalty + 0.1
-                yield dataclasses.replace(base, penalty=penalty)
+            yield from self._get_assignments_postcode(base, query.num_token_slots())
 
         # Postcode or country-only search
         if not base.address:
@@ -286,49 +373,19 @@ def get_assignments(self, query: qmod.QueryStruct) -> Iterator[TokenAssignment]:
             # <postcode>,<address> should give preference to postcode search
             if base.postcode and base.postcode.start == 0:
                 self.penalty += 0.1
-            # Use entire first word as name
+
+            # Right-to-left reading of the address
             if self.direction != -1:
-                log().comment('first word = name')
-                yield dataclasses.replace(base, name=base.address[0],
-                                          penalty=self.penalty,
-                                          address=base.address[1:])
-
-            # Use entire last word as name
-            if self.direction == -1 or (self.direction == 0 and len(base.address) > 1):
-                log().comment('last word = name')
-                yield dataclasses.replace(base, name=base.address[-1],
-                                          penalty=self.penalty,
-                                          address=base.address[:-1])
+                yield from self._get_assignments_address_forward(base, query)
+
+            # Left-to-right reading of the address
+            if self.direction != 1:
+                yield from self._get_assignments_address_backward(base, query)
 
             # variant for special housenumber searches
             if base.housenumber:
                 yield dataclasses.replace(base, penalty=self.penalty)
 
-            # Use beginning of first word as name
-            if self.direction != -1:
-                first = base.address[0]
-                if (not base.housenumber or first.end >= base.housenumber.start)\
-                   and (not base.qualifier or first.start >= base.qualifier.end):
-                    for i in range(first.start + 1, first.end):
-                        name, addr = first.split(i)
-                        penalty = self.penalty + PENALTY_TOKENCHANGE[query.nodes[i].btype]
-                        log().comment(f'split first word = name ({i - first.start})')
-                        yield dataclasses.replace(base, name=name, penalty=penalty,
-                                                  address=[addr] + base.address[1:])
-
-            # Use end of last word as name
-            if self.direction != 1:
-                last = base.address[-1]
-                if (not base.housenumber or last.start <= base.housenumber.end)\
-                   and (not base.qualifier or last.end <= base.qualifier.start):
-                    for i in range(last.start + 1, last.end):
-                        addr, name = last.split(i)
-                        penalty = self.penalty + PENALTY_TOKENCHANGE[query.nodes[i].btype]
-                        log().comment(f'split last word = name ({i - last.start})')
-                        yield dataclasses.replace(base, name=name, penalty=penalty,
-                                                  address=base.address[:-1] + [addr])
-
-
 
 def yield_token_assignments(query: qmod.QueryStruct) -> Iterator[TokenAssignment]:
     """ Return possible word type assignments to word positions.