]> git.openstreetmap.org Git - nominatim.git/blobdiff - nominatim/indexer/indexer.py
fetch place info asynchronously
[nominatim.git] / nominatim / indexer / indexer.py
index aa1fb8efb80c4c6156f0547e1fa71c1e76cc72d4..d685e83a1546097366faa41fe8bc580ad5b4e660 100644 (file)
@@ -3,6 +3,9 @@ Main work horse for indexing (computing addresses) the database.
 """
 import logging
 import select
+import time
+
+import psycopg2.extras
 
 from nominatim.indexer.progress import ProgressLogger
 from nominatim.indexer import runners
@@ -11,25 +14,78 @@ from nominatim.db.connection import connect
 
 LOG = logging.getLogger()
 
+class WorkerPool:
+    """ A pool of asynchronous database connections.
 
-class Indexer:
-    """ Main indexing routine.
+        The pool may be used as a context manager.
     """
+    REOPEN_CONNECTIONS_AFTER = 100000
 
-    def __init__(self, dsn, num_threads):
-        self.dsn = dsn
-        self.num_threads = num_threads
-        self.threads = []
+    def __init__(self, dsn, pool_size):
+        self.threads = [DBConnection(dsn) for _ in range(pool_size)]
+        self.free_workers = self._yield_free_worker()
 
 
-    def _setup_connections(self):
-        self.threads = [DBConnection(self.dsn) for _ in range(self.num_threads)]
+    def finish_all(self):
+        """ Wait for all connection to finish.
+        """
+        for thread in self.threads:
+            while not thread.is_done():
+                thread.wait()
 
+        self.free_workers = self._yield_free_worker()
 
-    def _close_connections(self):
+    def close(self):
+        """ Close all connections and clear the pool.
+        """
         for thread in self.threads:
             thread.close()
         self.threads = []
+        self.free_workers = None
+
+
+    def next_free_worker(self):
+        """ Get the next free connection.
+        """
+        return next(self.free_workers)
+
+
+    def _yield_free_worker(self):
+        ready = self.threads
+        command_stat = 0
+        while True:
+            for thread in ready:
+                if thread.is_done():
+                    command_stat += 1
+                    yield thread
+
+            if command_stat > self.REOPEN_CONNECTIONS_AFTER:
+                for thread in self.threads:
+                    while not thread.is_done():
+                        thread.wait()
+                    thread.connect()
+                ready = self.threads
+                command_stat = 0
+            else:
+                _, ready, _ = select.select([], self.threads, [])
+
+
+    def __enter__(self):
+        return self
+
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.close()
+
+
+class Indexer:
+    """ Main indexing routine.
+    """
+
+    def __init__(self, dsn, tokenizer, num_threads):
+        self.dsn = dsn
+        self.tokenizer = tokenizer
+        self.num_threads = num_threads
 
 
     def index_full(self, analyse=True):
@@ -42,27 +98,27 @@ class Indexer:
             conn.autocommit = True
 
             if analyse:
-                def _analyse():
+                def _analyze():
                     with conn.cursor() as cur:
-                        cur.execute('ANALYSE')
+                        cur.execute('ANALYZE')
             else:
-                def _analyse():
+                def _analyze():
                     pass
 
             self.index_by_rank(0, 4)
-            _analyse()
+            _analyze()
 
             self.index_boundaries(0, 30)
-            _analyse()
+            _analyze()
 
             self.index_by_rank(5, 25)
-            _analyse()
+            _analyze()
 
             self.index_by_rank(26, 30)
-            _analyse()
+            _analyze()
 
             self.index_postcodes()
-            _analyse()
+            _analyze()
 
 
     def index_boundaries(self, minrank, maxrank):
@@ -71,13 +127,9 @@ class Indexer:
         LOG.warning("Starting indexing boundaries using %s threads",
                     self.num_threads)
 
-        self._setup_connections()
-
-        try:
+        with self.tokenizer.name_analyzer() as analyzer:
             for rank in range(max(minrank, 4), min(maxrank, 26)):
-                self._index(runners.BoundaryRunner(rank))
-        finally:
-            self._close_connections()
+                self._index(runners.BoundaryRunner(rank, analyzer))
 
     def index_by_rank(self, minrank, maxrank):
         """ Index all entries of placex in the given rank range (inclusive)
@@ -90,20 +142,16 @@ class Indexer:
         LOG.warning("Starting indexing rank (%i to %i) using %i threads",
                     minrank, maxrank, self.num_threads)
 
-        self._setup_connections()
-
-        try:
+        with self.tokenizer.name_analyzer() as analyzer:
             for rank in range(max(1, minrank), maxrank):
-                self._index(runners.RankRunner(rank))
+                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)
+                self._index(runners.RankRunner(0, analyzer))
+                self._index(runners.InterpolationRunner(analyzer), 20)
+                self._index(runners.RankRunner(30, analyzer), 20)
             else:
-                self._index(runners.RankRunner(maxrank))
-        finally:
-            self._close_connections()
+                self._index(runners.RankRunner(maxrank, analyzer))
 
 
     def index_postcodes(self):
@@ -111,12 +159,8 @@ class Indexer:
         """
         LOG.warning("Starting indexing postcodes using %s threads", self.num_threads)
 
-        self._setup_connections()
+        self._index(runners.PostcodeRunner(), 20)
 
-        try:
-            self._index(runners.PostcodeRunner(), 20)
-        finally:
-            self._close_connections()
 
     def update_status_table(self):
         """ Update the status in the status table to 'indexed'.
@@ -135,60 +179,75 @@ class Indexer:
         LOG.warning("Starting %s (using batch size %s)", runner.name(), batch)
 
         with connect(self.dsn) as conn:
+            psycopg2.extras.register_hstore(conn)
             with conn.cursor() as cur:
                 total_tuples = cur.scalar(runner.sql_count_objects())
                 LOG.debug("Total number of rows: %i", total_tuples)
 
+                # need to fetch those manually because register_hstore cannot
+                # fetch them on an asynchronous connection below.
+                hstore_oid = cur.scalar("SELECT 'hstore'::regtype::oid")
+                hstore_array_oid = cur.scalar("SELECT 'hstore[]'::regtype::oid")
+
             conn.commit()
 
             progress = ProgressLogger(runner.name(), total_tuples)
 
+            fetcher_wait = 0
+            pool_wait = 0
+
             if total_tuples > 0:
                 with conn.cursor(name='places') as cur:
                     cur.execute(runner.sql_get_objects())
 
-                    next_thread = self.find_free_thread()
-                    while True:
-                        places = [p[0] for p in cur.fetchmany(batch)]
-                        if not places:
-                            break
+                    fetcher = DBConnection(self.dsn, cursor_factory=psycopg2.extras.DictCursor)
+                    psycopg2.extras.register_hstore(fetcher.conn,
+                                                    oid=hstore_oid,
+                                                    array_oid=hstore_array_oid)
 
-                        LOG.debug("Processing places: %s", str(places))
-                        thread = next(next_thread)
+                    with WorkerPool(self.dsn, self.num_threads) as pool:
+                        places = self._fetch_next_batch(cur, fetcher, runner)
+                        while places is not None:
+                            if not places:
+                                t0 = time.time()
+                                fetcher.wait()
+                                fetcher_wait += time.time() - t0
+                                places = fetcher.cursor.fetchall()
 
-                        thread.perform(runner.sql_index_place(places))
-                        progress.add(len(places))
+                            # asynchronously get the next batch
+                            next_places = self._fetch_next_batch(cur, fetcher, runner)
 
-            conn.commit()
+                            # And insert the curent batch
+                            for idx in range(0, len(places), batch):
+                                t0 = time.time()
+                                worker = pool.next_free_worker()
+                                pool_wait += time.time() - t0
+                                part = places[idx:idx+batch]
+                                LOG.debug("Processing places: %s", str(part))
+                                runner.index_places(worker, part)
+                                progress.add(len(part))
 
-        for thread in self.threads:
-            thread.wait()
+                            places = next_places
+
+                        pool.finish_all()
+
+                    fetcher.wait()
+                    fetcher.close()
+
+                conn.commit()
 
         progress.done()
+        LOG.warning("Wait time: fetcher: {}s,  pool: {}s".format(fetcher_wait, pool_wait))
 
-    def find_free_thread(self):
-        """ Generator that returns the next connection that is free for
-            sending a query.
-        """
-        ready = self.threads
-        command_stat = 0
 
-        while True:
-            for thread in ready:
-                if thread.is_done():
-                    command_stat += 1
-                    yield thread
+    def _fetch_next_batch(self, cur, fetcher, runner):
+        ids = cur.fetchmany(100)
 
-            # refresh the connections occasionaly to avoid potential
-            # memory leaks in Postgresql.
-            if command_stat > 100000:
-                for thread in self.threads:
-                    while not thread.is_done():
-                        thread.wait()
-                    thread.connect()
-                command_stat = 0
-                ready = self.threads
-            else:
-                ready, _, _ = select.select(self.threads, [], [])
+        if not ids:
+            return None
+
+        if not hasattr(runner, 'get_place_details'):
+            return ids
 
-        assert False, "Unreachable code"
+        runner.get_place_details(fetcher, ids)
+        return []