+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
"""
Functions for importing, updating and otherwise maintaining the table
of artificial postcode centroids.
"""
+from typing import Optional, Tuple, Dict, List, TextIO
+from collections import defaultdict
+from pathlib import Path
+import csv
+import gzip
+import logging
+from math import isfinite
-from nominatim.db.utils import execute_file
-from nominatim.db.connection import connect
+from psycopg2 import sql as pysql
-def import_postcodes(dsn, project_dir, tokenizer):
- """ Set up the initial list of postcodes.
+from nominatim.db.connection import connect, Connection
+from nominatim.utils.centroid import PointsCentroid
+from nominatim.data.postcode_format import PostcodeFormatter, CountryPostcodeMatcher
+from nominatim.tokenizer.base import AbstractAnalyzer, AbstractTokenizer
+
+LOG = logging.getLogger()
+
+def _to_float(numstr: str, max_value: float) -> float:
+ """ Convert the number in string into a float. The number is expected
+ to be in the range of [-max_value, max_value]. Otherwise rises a
+ ValueError.
"""
+ num = float(numstr)
+ if not isfinite(num) or num <= -max_value or num >= max_value:
+ raise ValueError()
+
+ return num
+
+class _PostcodeCollector:
+ """ Collector for postcodes of a single country.
+ """
+
+ def __init__(self, country: str, matcher: Optional[CountryPostcodeMatcher]):
+ self.country = country
+ self.matcher = matcher
+ self.collected: Dict[str, PointsCentroid] = defaultdict(PointsCentroid)
+ self.normalization_cache: Optional[Tuple[str, Optional[str]]] = None
+
+
+ def add(self, postcode: str, x: float, y: float) -> None:
+ """ Add the given postcode to the collection cache. If the postcode
+ already existed, it is overwritten with the new centroid.
+ """
+ if self.matcher is not None:
+ normalized: Optional[str]
+ if self.normalization_cache and self.normalization_cache[0] == postcode:
+ normalized = self.normalization_cache[1]
+ else:
+ match = self.matcher.match(postcode)
+ normalized = self.matcher.normalize(match) if match else None
+ self.normalization_cache = (postcode, normalized)
+
+ if normalized:
+ self.collected[normalized] += (x, y)
- with connect(dsn) as conn:
- conn.drop_table('gb_postcode')
- conn.drop_table('us_postcode')
+
+ def commit(self, conn: Connection, analyzer: AbstractAnalyzer, project_dir: Path) -> None:
+ """ Update postcodes for the country from the postcodes selected so far
+ as well as any externally supplied postcodes.
+ """
+ self._update_from_external(analyzer, project_dir)
+ to_add, to_delete, to_update = self._compute_changes(conn)
+
+ LOG.info("Processing country '%s' (%s added, %s deleted, %s updated).",
+ self.country, len(to_add), len(to_delete), len(to_update))
with conn.cursor() as cur:
- cur.execute("""CREATE TABLE gb_postcode (
- id integer,
- postcode character varying(9),
- geometry GEOMETRY(Point, 4326))""")
+ if to_add:
+ cur.execute_values(
+ """INSERT INTO location_postcode
+ (place_id, indexed_status, country_code,
+ postcode, geometry) VALUES %s""",
+ to_add,
+ template=pysql.SQL("""(nextval('seq_place'), 1, {},
+ %s, 'SRID=4326;POINT(%s %s)')
+ """).format(pysql.Literal(self.country)))
+ if to_delete:
+ cur.execute("""DELETE FROM location_postcode
+ WHERE country_code = %s and postcode = any(%s)
+ """, (self.country, to_delete))
+ if to_update:
+ cur.execute_values(
+ pysql.SQL("""UPDATE location_postcode
+ SET indexed_status = 2,
+ geometry = ST_SetSRID(ST_Point(v.x, v.y), 4326)
+ FROM (VALUES %s) AS v (pc, x, y)
+ WHERE country_code = {} and postcode = pc
+ """).format(pysql.Literal(self.country)), to_update)
+
+ def _compute_changes(self, conn: Connection) \
+ -> Tuple[List[Tuple[str, float, float]], List[str], List[Tuple[str, float, float]]]:
+ """ Compute which postcodes from the collected postcodes have to be
+ added or modified and which from the location_postcode table
+ have to be deleted.
+ """
+ to_update = []
+ to_delete = []
with conn.cursor() as cur:
- cur.execute("""CREATE TABLE us_postcode (
- postcode text,
- x double precision,
- y double precision)""")
- conn.commit()
+ cur.execute("""SELECT postcode, ST_X(geometry), ST_Y(geometry)
+ FROM location_postcode
+ WHERE country_code = %s""",
+ (self.country, ))
+ for postcode, x, y in cur:
+ pcobj = self.collected.pop(postcode, None)
+ if pcobj:
+ newx, newy = pcobj.centroid()
+ if (x - newx) > 0.0000001 or (y - newy) > 0.0000001:
+ to_update.append((postcode, newx, newy))
+ else:
+ to_delete.append(postcode)
- gb_postcodes = project_dir / 'gb_postcode_data.sql.gz'
- if gb_postcodes.is_file():
- execute_file(dsn, gb_postcodes)
+ to_add = [(k, *v.centroid()) for k, v in self.collected.items()]
+ self.collected = defaultdict(PointsCentroid)
- us_postcodes = project_dir / 'us_postcode_data.sql.gz'
- if us_postcodes.is_file():
- execute_file(dsn, us_postcodes)
+ return to_add, to_delete, to_update
- with conn.cursor() as cur:
- cur.execute("TRUNCATE location_postcode")
- cur.execute("""
- INSERT INTO location_postcode
- (place_id, indexed_status, country_code, postcode, geometry)
- SELECT nextval('seq_place'), 1, country_code,
- token_normalized_postcode(address->'postcode') as pc,
- ST_Centroid(ST_Collect(ST_Centroid(geometry)))
- FROM placex
- WHERE address ? 'postcode'
- and token_normalized_postcode(address->'postcode') is not null
- AND geometry IS NOT null
- GROUP BY country_code, pc
- """)
-
- cur.execute("""
- INSERT INTO location_postcode
- (place_id, indexed_status, country_code, postcode, geometry)
- SELECT nextval('seq_place'), 1, 'us',
- token_normalized_postcode(postcode),
- ST_SetSRID(ST_Point(x,y),4326)
- FROM us_postcode WHERE token_normalized_postcode(postcode) NOT IN
- (SELECT postcode FROM location_postcode
- WHERE country_code = 'us')
- """)
-
- cur.execute("""
- INSERT INTO location_postcode
- (place_id, indexed_status, country_code, postcode, geometry)
- SELECT nextval('seq_place'), 1, 'gb',
- token_normalized_postcode(postcode), geometry
- FROM gb_postcode WHERE token_normalized_postcode(postcode) NOT IN
- (SELECT postcode FROM location_postcode
- WHERE country_code = 'gb')
- """)
-
- cur.execute("""
- DELETE FROM word WHERE class='place' and type='postcode'
- and word NOT IN (SELECT postcode FROM location_postcode)
- """)
- conn.commit()
-
- with tokenizer.name_analyzer() as analyzer:
- analyzer.add_postcodes_from_db()
+
+ def _update_from_external(self, analyzer: AbstractAnalyzer, project_dir: Path) -> None:
+ """ Look for an external postcode file for the active country in
+ the project directory and add missing postcodes when found.
+ """
+ csvfile = self._open_external(project_dir)
+ if csvfile is None:
+ return
+
+ try:
+ reader = csv.DictReader(csvfile)
+ for row in reader:
+ if 'postcode' not in row or 'lat' not in row or 'lon' not in row:
+ LOG.warning("Bad format for external postcode file for country '%s'."
+ " Ignored.", self.country)
+ return
+ postcode = analyzer.normalize_postcode(row['postcode'])
+ if postcode not in self.collected:
+ try:
+ # Do float conversation separately, it might throw
+ centroid = (_to_float(row['lon'], 180),
+ _to_float(row['lat'], 90))
+ self.collected[postcode] += centroid
+ except ValueError:
+ LOG.warning("Bad coordinates %s, %s in %s country postcode file.",
+ row['lat'], row['lon'], self.country)
+
+ finally:
+ csvfile.close()
+
+
+ def _open_external(self, project_dir: Path) -> Optional[TextIO]:
+ fname = project_dir / f'{self.country}_postcodes.csv'
+
+ if fname.is_file():
+ LOG.info("Using external postcode file '%s'.", fname)
+ return open(fname, 'r', encoding='utf-8')
+
+ fname = project_dir / f'{self.country}_postcodes.csv.gz'
+
+ if fname.is_file():
+ LOG.info("Using external postcode file '%s'.", fname)
+ return gzip.open(fname, 'rt')
+
+ return None
+
+
+def update_postcodes(dsn: str, project_dir: Path, tokenizer: AbstractTokenizer) -> None:
+ """ Update the table of artificial postcodes.
+
+ Computes artificial postcode centroids from the placex table,
+ potentially enhances it with external data and then updates the
+ postcodes in the table 'location_postcode'.
+ """
+ matcher = PostcodeFormatter()
+ with tokenizer.name_analyzer() as analyzer:
+ with connect(dsn) as conn:
+ # First get the list of countries that currently have postcodes.
+ # (Doing this before starting to insert, so it is fast on import.)
+ with conn.cursor() as cur:
+ cur.execute("SELECT DISTINCT country_code FROM location_postcode")
+ todo_countries = set((row[0] for row in cur))
+
+ # Recompute the list of valid postcodes from placex.
+ with conn.cursor(name="placex_postcodes") as cur:
+ cur.execute("""
+ SELECT cc, pc, ST_X(centroid), ST_Y(centroid)
+ FROM (SELECT
+ COALESCE(plx.country_code,
+ get_country_code(ST_Centroid(pl.geometry))) as cc,
+ pl.address->'postcode' as pc,
+ COALESCE(plx.centroid, ST_Centroid(pl.geometry)) as centroid
+ FROM place AS pl LEFT OUTER JOIN placex AS plx
+ ON pl.osm_id = plx.osm_id AND pl.osm_type = plx.osm_type
+ WHERE pl.address ? 'postcode' AND pl.geometry IS NOT null) xx
+ WHERE pc IS NOT null AND cc IS NOT null
+ ORDER BY cc, pc""")
+
+ collector = None
+
+ for country, postcode, x, y in cur:
+ if collector is None or country != collector.country:
+ if collector is not None:
+ collector.commit(conn, analyzer, project_dir)
+ collector = _PostcodeCollector(country, matcher.get_matcher(country))
+ todo_countries.discard(country)
+ collector.add(postcode, x, y)
+
+ if collector is not None:
+ collector.commit(conn, analyzer, project_dir)
+
+ # Now handle any countries that are only in the postcode table.
+ for country in todo_countries:
+ fmt = matcher.get_matcher(country)
+ _PostcodeCollector(country, fmt).commit(conn, analyzer, project_dir)
+
+ conn.commit()
+
+ analyzer.update_postcodes_from_db()
+
+def can_compute(dsn: str) -> bool:
+ """
+ Check that the place table exists so that
+ postcodes can be computed.
+ """
+ with connect(dsn) as conn:
+ return conn.table_exists('place')