1 # SPDX-License-Identifier: GPL-2.0-only
3 # This file is part of Nominatim. (https://nominatim.org)
5 # Copyright (C) 2022 by the Nominatim developer community.
6 # For a full list of authors see the git log.
8 Preprocessing of SQL files.
10 from typing import Set, Dict, Any
13 from nominatim.db.connection import Connection
14 from nominatim.db.async_connection import WorkerPool
15 from nominatim.config import Configuration
17 def _get_partitions(conn: Connection) -> Set[int]:
18 """ Get the set of partitions currently in use.
20 with conn.cursor() as cur:
21 cur.execute('SELECT DISTINCT partition FROM country_name')
24 partitions.add(row[0])
29 def _get_tables(conn: Connection) -> Set[str]:
30 """ Return the set of tables currently in use.
31 Only includes non-partitioned
33 with conn.cursor() as cur:
34 cur.execute("SELECT tablename FROM pg_tables WHERE schemaname = 'public'")
36 return set((row[0] for row in list(cur)))
39 def _setup_tablespace_sql(config: Configuration) -> Dict[str, str]:
40 """ Returns a dict with tablespace expressions for the different tablespace
41 kinds depending on whether a tablespace is configured or not.
44 for subset in ('ADDRESS', 'SEARCH', 'AUX'):
45 for kind in ('DATA', 'INDEX'):
46 tspace = getattr(config, f'TABLESPACE_{subset}_{kind}')
48 tspace = f'TABLESPACE "{tspace}"'
49 out[f'{subset.lower()}_{kind.lower()}'] = tspace
54 def _setup_postgresql_features(conn: Connection) -> Dict[str, Any]:
55 """ Set up a dictionary with various optional Postgresql/Postgis features that
56 depend on the database version.
58 pg_version = conn.server_version_tuple()
59 postgis_version = conn.postgis_version_tuple()
60 pg11plus = pg_version >= (11, 0, 0)
61 ps3 = postgis_version >= (3, 0)
63 'has_index_non_key_column': pg11plus,
64 'spgist_geom' : 'SPGIST' if pg11plus and ps3 else 'GIST'
67 class SQLPreprocessor:
68 """ A environment for preprocessing SQL files from the
71 The preprocessor provides a number of default filters and variables.
72 The variables may be overwritten when rendering an SQL file.
74 The preprocessing is currently based on the jinja2 templating library
75 and follows its syntax.
78 def __init__(self, conn: Connection, config: Configuration) -> None:
79 self.env = jinja2.Environment(autoescape=False,
80 loader=jinja2.FileSystemLoader(str(config.lib_dir.sql)))
82 db_info: Dict[str, Any] = {}
83 db_info['partitions'] = _get_partitions(conn)
84 db_info['tables'] = _get_tables(conn)
85 db_info['reverse_only'] = 'search_name' not in db_info['tables']
86 db_info['tablespace'] = _setup_tablespace_sql(config)
88 self.env.globals['config'] = config
89 self.env.globals['db'] = db_info
90 self.env.globals['postgres'] = _setup_postgresql_features(conn)
93 def run_string(self, conn: Connection, template: str, **kwargs: Any) -> None:
94 """ Execute the given SQL template string on the connection.
95 The keyword arguments may supply additional parameters
98 sql = self.env.from_string(template).render(**kwargs)
100 with conn.cursor() as cur:
105 def run_sql_file(self, conn: Connection, name: str, **kwargs: Any) -> None:
106 """ Execute the given SQL file on the connection. The keyword arguments
107 may supply additional parameters for preprocessing.
109 sql = self.env.get_template(name).render(**kwargs)
111 with conn.cursor() as cur:
116 def run_parallel_sql_file(self, dsn: str, name: str, num_threads: int = 1,
117 **kwargs: Any) -> None:
118 """ Execure the given SQL files using parallel asynchronous connections.
119 The keyword arguments may supply additional parameters for
122 After preprocessing the SQL code is cut at lines containing only
123 '---'. Each chunk is sent to one of the `num_threads` workers.
125 sql = self.env.get_template(name).render(**kwargs)
127 parts = sql.split('\n---\n')
129 with WorkerPool(dsn, num_threads) as pool:
131 pool.next_free_worker().perform(part)