introduce name analyzer

The name analyzer is the actual work horse of the tokenizer. It
is instantiated on a thread-base and provides all functions for
analysing names and queries.

nominatim/indexer/indexer.py

@@ -124,8 +124,9 @@ class Indexer:
         LOG.warning("Starting indexing boundaries using %s threads",
                     self.num_threads)
 
-        for rank in range(max(minrank, 4), min(maxrank, 26)):
-            self._index(runners.BoundaryRunner(rank))
+        with self.tokenizer.name_analyzer() as analyzer:
+            for rank in range(max(minrank, 4), min(maxrank, 26)):
+                self._index(runners.BoundaryRunner(rank, analyzer))
 
     def index_by_rank(self, minrank, maxrank):
         """ Index all entries of placex in the given rank range (inclusive)
@@ -138,15 +139,16 @@ class Indexer:
         LOG.warning("Starting indexing rank (%i to %i) using %i threads",
                     minrank, maxrank, self.num_threads)
 
-        for rank in range(max(1, minrank), maxrank):
-            self._index(runners.RankRunner(rank))
+        with self.tokenizer.name_analyzer() as analyzer:
+            for rank in range(max(1, minrank), maxrank):
+                self._index(runners.RankRunner(rank, analyzer))
 
-        if maxrank == 30:
-            self._index(runners.RankRunner(0))
-            self._index(runners.InterpolationRunner(), 20)
-            self._index(runners.RankRunner(30), 20)
-        else:
-            self._index(runners.RankRunner(maxrank))
+            if maxrank == 30:
+                self._index(runners.RankRunner(0, analyzer))
+                self._index(runners.InterpolationRunner(), 20)
+                self._index(runners.RankRunner(30, analyzer), 20)
+            else:
+                self._index(runners.RankRunner(maxrank, analyzer))
 
 
     def index_postcodes(self):

nominatim/indexer/runners.py

@@ -2,6 +2,10 @@
 Mix-ins that provide the actual commands for the indexer for various indexing
 tasks.
 """
+import functools
+
+import psycopg2.extras
+
 # pylint: disable=C0111
 
 class AbstractPlacexRunner:
@@ -9,28 +13,26 @@ class AbstractPlacexRunner:
     """
     SELECT_SQL = 'SELECT place_id, (placex_prepare_update(placex)).* FROM placex'
 
-    def __init__(self, rank):
+    def __init__(self, rank, analyzer):
         self.rank = rank
-        self._sql_terms = 0
-        self._cached_index_sql = None
+        self.analyzer = analyzer
 
-    def _index_sql(self, num_places):
-        if num_places != self._sql_terms:
-            self._cached_index_sql = \
-                """ UPDATE placex
-                    SET indexed_status = 0, address = v.addr
-                    FROM (VALUES {}) as v(id, addr)
-                    WHERE place_id = v.id
-                """.format(','.join(["(%s, %s::hstore)"]  * num_places))
-            self._sql_terms = num_places
 
-        return self._cached_index_sql
+    @staticmethod
+    @functools.lru_cache(maxsize=1)
+    def _index_sql(num_places):
+        return """ UPDATE placex
+                   SET indexed_status = 0, address = v.addr, token_info = v.ti
+                   FROM (VALUES {}) as v(id, addr, ti)
+                   WHERE place_id = v.id
+               """.format(','.join(["(%s, %s::hstore, %s::json)"]  * num_places))
 
 
     def index_places(self, worker, places):
         values = []
         for place in places:
             values.extend((place[x] for x in ('place_id', 'address')))
+            values.append(psycopg2.extras.Json(self.analyzer.process_place(place)))
 
         worker.perform(self._index_sql(len(places)), values)
 

nominatim/tokenizer/legacy_tokenizer.py

@@ -5,6 +5,7 @@ import logging
 import shutil
 
 import psycopg2
+import psycopg2.extras
 
 from nominatim.db.connection import connect
 from nominatim.db import properties
@@ -140,6 +141,24 @@ class LegacyTokenizer:
             self._save_config(conn, config)
 
 
+    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 LegacyNameAnalyzer(self.dsn)
+
+
     def _init_db_tables(self, config):
         """ Set up the word table and fill it with pre-computed word
             frequencies.
@@ -159,3 +178,42 @@ class LegacyTokenizer:
         """
         properties.set_property(conn, DBCFG_NORMALIZATION, self.normalization)
         properties.set_property(conn, DBCFG_MAXWORDFREQ, config.MAX_WORD_FREQUENCY)
+
+
+
+class LegacyNameAnalyzer:
+    """ The legacy analyzer uses the special Postgresql module for
+        splitting names.
+
+        Each instance opens a connection to the database to request the
+        normalization.
+    """
+
+    def __init__(self, dsn):
+        self.conn = connect(dsn).connection
+        self.conn.autocommit = True
+        psycopg2.extras.register_hstore(self.conn)
+
+
+    def __enter__(self):
+        return self
+
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.close()
+
+
+    def close(self):
+        """ Free all resources used by the analyzer.
+        """
+        if self.conn:
+            self.conn.close()
+            self.conn = None
+
+    def process_place(self, place):
+        """ Determine tokenizer information about the given place.
+
+            Returns a JSON-serialisable structure that will be handed into
+            the database via the token_info field.
+        """
+        return {}

test/python/dummy_tokenizer.py

@@ -23,3 +23,30 @@ class DummyTokenizer:
     def init_from_project(self):
         assert self.init_state == None
         self.init_state = "loaded"
+
+
+    def name_analyzer(self):
+        return DummyNameAnalyzer()
+
+
+class DummyNameAnalyzer:
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.close()
+
+
+    def close(self):
+        """ Free all resources used by the analyzer.
+        """
+        pass
+
+    def process_place(self, place):
+        """ Determine tokenizer information about the given place.
+
+            Returns a JSON-serialisable structure that will be handed into
+            the database via the token_info field.
+        """
+        return {}

test/python/test_indexing.py

@@ -29,6 +29,7 @@ class IndexerTestDB:
                                                 partition SMALLINT,
                                                 admin_level SMALLINT,
                                                 address HSTORE,
+                                                token_info JSONB,
                                                 geometry_sector INTEGER)""")
             cur.execute("""CREATE TABLE location_property_osmline (
                                place_id BIGINT,