X-Git-Url: http://git.veekun.com/zzz-pokedex.git/blobdiff_plain/4fe48baffb5156027c6d186308998412554a6906..fe8bf85948addbd41a20b1752343a749df22dc16:/pokedex/lookup.py diff --git a/pokedex/lookup.py b/pokedex/lookup.py index dcc3e7a..37a50f3 100644 --- a/pokedex/lookup.py +++ b/pokedex/lookup.py @@ -1,11 +1,17 @@ # encoding: utf8 +import os, os.path +import pkg_resources import re from sqlalchemy.sql import func import whoosh +import whoosh.filedb.filestore +import whoosh.filedb.fileindex +import whoosh.index from whoosh.qparser import QueryParser import whoosh.spelling +from pokedex.db import connect import pokedex.db.tables as tables # Dictionary of table name => table class. @@ -13,33 +19,81 @@ import pokedex.db.tables as tables # retrieve something from the index indexed_tables = {} for cls in [ + tables.Ability, + tables.Item, + tables.Move, tables.Pokemon, + tables.Type, ]: indexed_tables[cls.__tablename__] = cls -index_bits = {} -def get_index(session): - """Returns (index, speller). - - Creates an index if one does not exist. +# Dictionary of extra keys to file types of objects under, e.g. Pokémon can +# also be looked up purely by number +extra_keys = { + tables.Move: [ + lambda row: u"move %d" % row.id, + ], + tables.Pokemon: [ + lambda row: unicode(row.id), + ], +} + +def open_index(directory=None, session=None, recreate=False): + """Opens the whoosh index stored in the named directory and returns (index, + speller). If the index doesn't already exist, it will be created. + + `directory` + Directory containing the index. Defaults to a location within the + `pokedex` egg directory. + + `session` + If the index needs to be created, this database session will be used. + Defaults to an attempt to connect to the default SQLite database + installed by `pokedex setup`. + + `recreate` + If set to True, the whoosh index will be created even if it already + exists. """ - if index_bits: - return index_bits['index'], index_bits['speller'] + # Defaults + if not directory: + directory = pkg_resources.resource_filename('pokedex', + 'data/whoosh_index') + + if not session: + session = connect() + + # Attempt to open or create the index + directory_exists = os.path.exists(directory) + if directory_exists and not recreate: + # Already exists; should be an index! + try: + index = whoosh.index.open_dir(directory, indexname='pokedex') + speller = whoosh.index.open_dir(directory, indexname='spelling') + return index, speller + except whoosh.index.EmptyIndexError as e: + # Apparently not a real index. Fall out of the if and create it + pass + + if not directory_exists: + os.mkdir(directory) + - store = whoosh.store.RamStorage() + # Create index schema = whoosh.fields.Schema( name=whoosh.fields.ID(stored=True), - spelling_name=whoosh.fields.ID(stored=True), table=whoosh.fields.STORED, row_id=whoosh.fields.STORED, - language_id=whoosh.fields.STORED, + language=whoosh.fields.STORED, ) - index = whoosh.index.Index(store, schema=schema, create=True) + index = whoosh.index.create_in(directory, schema=schema, + indexname='pokedex') writer = index.writer() # Index every name in all our tables of interest + speller_entries = [] for cls in indexed_tables.values(): q = session.query(cls) @@ -48,31 +102,34 @@ def get_index(session): q = q.filter_by(forme_base_pokemon_id=None) for row in q.yield_per(5): + row_key = dict(table=cls.__tablename__, row_id=row.id) + + # Spelling index only indexes strings of letters, alas, so we + # reduce every name to this to make the index work. However, exact + # matches are not returned, so e.g. 'nidoran' would neither match + # exactly nor fuzzy-match. Solution: add the spelling-munged name + # as a regular index row too. name = row.name.lower() - spelling_name = re.sub('[^a-z]', '', name) - writer.add_document(name=name, - spelling_name=spelling_name, - table=cls.__tablename__, - row_id=row.id) + writer.add_document(name=name, **row_key) + + speller_entries.append(name) + + for extra_key_func in extra_keys.get(cls, []): + extra_key = extra_key_func(row) + writer.add_document(name=extra_key, **row_key) writer.commit() - ### Construct a spell-checker index - speller = whoosh.spelling.SpellChecker(index.storage) + # Construct and populate a spell-checker index. Quicker to do it all + # at once, as every call to add_* does a commit(), and those seem to be + # expensive + speller = whoosh.spelling.SpellChecker(index.storage, indexname='spelling') + speller.add_words(speller_entries) - # Can't use speller.add_field because it tries to intuit a frequency, and - # names are in an ID field, which seems to be immune to frequency. - # Not hard to add everything ourselves, though - reader = index.doc_reader() - speller.add_words([ _['spelling_name'] for _ in reader ]) - reader.close() + return index, speller - index_bits['index'] = index - index_bits['speller'] = speller - index_bits['store'] = store - return index_bits['index'], index_bits['speller'] -def lookup(session, name, exact_only=False): +def lookup(name, session=None, exact_only=False): """Attempts to find some sort of object, given a database session and name. Returns (objects, exact) where `objects` is a list of database objects, and @@ -84,39 +141,43 @@ def lookup(session, name, exact_only=False): Currently recognizes: - Pokémon names: "Eevee" + + `name` + Name of the thing to look for. + + `session` + A database session to use for retrieving objects. As with get_index, + if this is not provided, a connection to the default database will be + attempted. + + `exact_only` + If True, only exact matches are returned. If set to False (the + default), and the provided `name` doesn't match anything exactly, + spelling correction will be attempted. """ + if not session: + session = connect() + + index, speller = open_index() + exact = True - # Alas! We have to make three attempts to find anything with this index. - # First: Try an exact match for a name in the index. - # Second: Try an exact match for a stripped-down name in the index. - # Third: Get spelling suggestions. - # The spelling module apparently only indexes *words* -- that is, [a-z]+. - # So we have a separate field that contains the same name, stripped down to - # just [a-z]+. - # Unfortunately, exact matches aren't returned as spelling suggestions, so - # we also have to do a regular index match against this separate field. - # Otherwise, 'nidoran' will never match anything - index, speller = get_index(session) - - # Look for exact name - parser = QueryParser('name', schema=index.schema) - results = index.find(name.lower(), parser=parser) + # Look for exact name. A Term object does an exact match, so we don't have + # to worry about a query parser tripping on weird characters in the input + searcher = index.searcher() + query = whoosh.query.Term('name', name.lower()) + results = searcher.search(query) if not exact_only: - # Look for a match with a reduced a-z name - if not results: - parser = QueryParser('spelling_name', schema=index.schema) - results = index.find(name.lower(), parser=parser) - # Look for some fuzzy matches if not results: - results = [] exact = False + results = [] for suggestion in speller.suggest(name, 3): - results.extend( index.find(suggestion, parser=parser) ) + query = whoosh.query.Term('name', suggestion) + results.extend(searcher.search(query)) # Convert results to db objects objects = []