| # 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. | |
| """Simple LIKE rewrites shared by scalar readers and search filtering.""" | |
| def try_optimize_like(literal): | |
| """Follow Java LikeOptimization, leaving escaped/underscore patterns intact.""" | |
| if literal is None: | |
| return None | |
| pattern = str(literal) | |
| if "_" in pattern or "\\" in pattern: | |
| return None | |
| if "%" not in pattern and pattern: | |
| return "equal", pattern | |
| if (pattern.startswith("%") and pattern.endswith("%") | |
| and pattern.count("%") == 2 and pattern[1:-1]): | |
| return "contains", pattern[1:-1] | |
| if pattern.startswith("%") and pattern.count("%") == 1 and pattern[1:]: | |
| return "ends_with", pattern[1:] | |
| if pattern.endswith("%") and pattern.count("%") == 1 and pattern[:-1]: | |
| return "starts_with", pattern[:-1] | |
| return None |