Merge remote-tracking branch 'upstream/master'

[nominatim.git] / nominatim / tokenizer / base.py

diff --git a/nominatim/tokenizer/base.py b/nominatim/tokenizer/base.py
index 00ecae447c5843eb0fc772960a421e271a82cb1d..f81b3bc262ed9f690b0eb6bc794e2cab076de822 100644 (file)
--- a/nominatim/tokenizer/base.py
+++ b/nominatim/tokenizer/base.py
@@ -1,3 +1,9 @@
+# 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.
 """
 Abstract class defintions for tokenizers. These base classes are here
 mainly for documentation purposes.
@@ -6,6 +12,7 @@ from abc import ABC, abstractmethod
 from typing import List, Tuple, Dict, Any
 
 from nominatim.config import Configuration
+from nominatim.indexer.place_info import PlaceInfo
 
 # pylint: disable=unnecessary-pass
 
@@ -29,7 +36,6 @@ class AbstractAnalyzer(ABC):
     def close(self) -> None:
         """ Free all resources used by the analyzer.
         """
-        pass
 
 
     @abstractmethod
@@ -49,7 +55,6 @@ class AbstractAnalyzer(ABC):
                 found for the given words. Each list entry is a tuple of
                 (original word, word token, word id).
         """
-        pass
 
 
     @abstractmethod
@@ -65,7 +70,6 @@ class AbstractAnalyzer(ABC):
             Returns:
                 The given postcode after normalization.
         """
-        pass
 
 
     @abstractmethod
@@ -73,7 +77,6 @@ class AbstractAnalyzer(ABC):
         """ Update the tokenizer's postcode tokens from the current content
             of the `location_postcode` table.
         """
-        pass
 
 
     @abstractmethod
@@ -89,7 +92,6 @@ class AbstractAnalyzer(ABC):
                                 When false, just add the given phrases to the
                                 ones that already exist.
         """
-        pass
 
 
     @abstractmethod
@@ -101,24 +103,16 @@ class AbstractAnalyzer(ABC):
                               refer to.
                 names: Dictionary of name type to name.
         """
-        pass
 
 
     @abstractmethod
-    def process_place(self, place: Dict) -> Any:
+    def process_place(self, place: PlaceInfo) -> Any:
         """ Extract tokens for the given place and compute the
             information to be handed to the PL/pgSQL processor for building
             the search index.
 
             Arguments:
-                place: Dictionary with the information about the place. Currently
-                       the following fields may be present:
-
-                       - *name* is a dictionary of names for the place together
-                         with the designation of the name.
-                       - *address* is a dictionary of address terms.
-                       - *country_feature* is set to a country code when the
-                         place describes a country.
+                place: Place information retrived from the database.
 
             Returns:
                 A JSON-serialisable structure that will be handed into
@@ -142,7 +136,7 @@ class AbstractTokenizer(ABC):
             the tokenizer remains stable over updates.
 
             Arguments:
-              config: Read-only object with configuration obtions.
+              config: Read-only object with configuration options.
 
               init_db: When set to False, then initialisation of database
                 tables should be skipped. This option is only required for
@@ -151,17 +145,18 @@ class AbstractTokenizer(ABC):
 
             TODO: can we move the init_db parameter somewhere else?
         """
-        pass
 
 
     @abstractmethod
-    def init_from_project(self) -> None:
+    def init_from_project(self, config: Configuration) -> None:
         """ Initialise the tokenizer from an existing database setup.
 
             The function should load all previously saved configuration from
             the project directory and/or the property table.
+
+            Arguments:
+              config: Read-only object with configuration options.
         """
-        pass
 
 
     @abstractmethod
@@ -172,9 +167,8 @@ class AbstractTokenizer(ABC):
             during query time.
 
             Arguments:
-              config: Read-only object with configuration obtions.
+              config: Read-only object with configuration options.
         """
-        pass
 
 
     @abstractmethod
@@ -187,24 +181,39 @@ class AbstractTokenizer(ABC):
             data structures or data itself must not be changed by this function.
 
             Arguments:
-              config: Read-only object with configuration obtions.
+              config: Read-only object with configuration options.
         """
-        pass
 
 
     @abstractmethod
-    def check_database(self) -> str:
+    def check_database(self, config: Configuration) -> str:
         """ Check that the database is set up correctly and ready for being
             queried.
 
+            Arguments:
+              config: Read-only object with configuration options.
+
             Returns:
               If an issue was found, return an error message with the
               description of the issue as well as hints for the user on
-              how to resolve the issue.
+              how to resolve the issue. If everything is okay, return `None`.
+        """
 
-              Return `None`, if no issue was found.
+
+    @abstractmethod
+    def update_statistics(self) -> None:
+        """ Recompute any tokenizer statistics necessary for efficient lookup.
+            This function is meant to be called from time to time by the user
+            to improve performance. However, the tokenizer must not depend on
+            it to be called in order to work.
+        """
+
+
+    @abstractmethod
+    def update_word_tokens(self) -> None:
+        """ Do house-keeping on the tokenizers internal data structures.
+            Remove unused word tokens, resort data etc.
         """
-        pass
 
 
     @abstractmethod
@@ -221,4 +230,3 @@ class AbstractTokenizer(ABC):
             When used outside the with construct, the caller must ensure to
             call the close() function before destructing the analyzer.
         """
-        pass