# 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
+Abstract class definitions for tokenizers. These base classes are here
mainly for documentation purposes.
"""
from abc import ABC, abstractmethod
from pathlib import Path
from nominatim.config import Configuration
+from nominatim.db.connection import Connection
from nominatim.data.place_info import PlaceInfo
from nominatim.typing import Protocol
Returns:
The function returns the list of all tuples that could be
- found for the given words. Each list entry is a tuple of
- (original word, word token, word id).
+ found for the given words. Each list entry is a tuple of
+ (original word, word token, word id).
"""
the search index.
Arguments:
- place: Place information retrived from the database.
+ place: Place information retrieved from the database.
Returns:
A JSON-serialisable structure that will be handed into
- the database via the `token_info` field.
+ the database via the `token_info` field.
"""
init_db: When set to False, then initialisation of database
tables should be skipped. This option is only required for
- migration purposes and can be savely ignored by custom
+ migration purposes and can be safely ignored by custom
tokenizers.
-
- TODO: can we move the init_db parameter somewhere else?
"""
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. If everything is okay, return `None`.
+ description of the issue as well as hints for the user on
+ how to resolve the issue. If everything is okay, return `None`.
"""
@abstractmethod
- def update_statistics(self) -> None:
+ def update_statistics(self, config: Configuration, threads: int = 1) -> 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
"""
+ @abstractmethod
+ def most_frequent_words(self, conn: Connection, num: int) -> List[str]:
+ """ Return a list of the most frequent full words in the database.
+
+ Arguments:
+ conn: Open connection to the database which may be used to
+ retrieve the words.
+ num: Maximum number of words to return.
+ """
+
+
class TokenizerModule(Protocol):
""" Interface that must be exported by modules that implement their
own tokenizer.