atris commented on a change in pull request #7405: URL: https://github.com/apache/pinot/pull/7405#discussion_r710142729
########## File path: pinot-segment-local/src/main/java/org/apache/pinot/segment/local/utils/nativefst/utils/RegexpMatcher.java ########## @@ -0,0 +1,170 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.pinot.segment.local.utils.nativefst.utils; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.Set; +import org.apache.pinot.segment.local.utils.nativefst.FST; +import org.apache.pinot.segment.local.utils.nativefst.automaton.Automaton; +import org.apache.pinot.segment.local.utils.nativefst.automaton.CharacterRunAutomaton; +import org.apache.pinot.segment.local.utils.nativefst.automaton.RegExp; +import org.apache.pinot.segment.local.utils.nativefst.automaton.State; +import org.apache.pinot.segment.local.utils.nativefst.automaton.Transition; + + +/** + * RegexpMatcher is a helper to retrieve matching values for a given regexp query. + * Regexp query is converted into an automaton and we run the matching algorithm on FST. + * + * Two main functions of this class are + * regexMatchOnFST() Function runs matching on FST (See function comments for more details) + * match(input) Function builds the automaton and matches given input. + */ +public class RegexpMatcher { + private final String _regexQuery; + private final FST _fst; + private final Automaton _automaton; + + public RegexpMatcher(String regexQuery, FST fst) { + _regexQuery = regexQuery; + _fst = fst; + + _automaton = new RegExp(_regexQuery).toAutomaton(); + } + + public static List<Long> regexMatch(String regexQuery, FST fst) { Review comment: Returning an iterator would still need building a list internally, right? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
