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| 1 | +/* |
| 2 | + * Copyright (c) 2025 Alibaba Group Holding Ltd. |
| 3 | + * |
| 4 | + * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | + * you may not use this file except in compliance with the License. |
| 6 | + * You may obtain a copy of the License at |
| 7 | + * |
| 8 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | + * |
| 10 | + * Unless required by applicable law or agreed to in writing, software |
| 11 | + * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | + * See the License for the specific language governing permissions and |
| 14 | + * limitations under the License. |
| 15 | + */ |
| 16 | + |
| 17 | +package com.alibaba.fluss.lake.paimon.utils; |
| 18 | + |
| 19 | +import com.alibaba.fluss.predicate.And; |
| 20 | +import com.alibaba.fluss.predicate.CompoundPredicate; |
| 21 | +import com.alibaba.fluss.predicate.FieldRef; |
| 22 | +import com.alibaba.fluss.predicate.FunctionVisitor; |
| 23 | +import com.alibaba.fluss.predicate.LeafPredicate; |
| 24 | +import com.alibaba.fluss.predicate.Or; |
| 25 | +import com.alibaba.fluss.predicate.PredicateVisitor; |
| 26 | + |
| 27 | +import org.apache.paimon.predicate.Predicate; |
| 28 | +import org.apache.paimon.predicate.PredicateBuilder; |
| 29 | +import org.apache.paimon.types.RowType; |
| 30 | + |
| 31 | +import java.util.List; |
| 32 | +import java.util.Optional; |
| 33 | +import java.util.stream.Collectors; |
| 34 | + |
| 35 | +/** |
| 36 | + * Converts a Fluss {@link com.alibaba.fluss.predicate.Predicate} into a Paimon {@link Predicate}. |
| 37 | + * |
| 38 | + * <p>This class implements the {@link PredicateVisitor} pattern to traverse a tree of Fluss |
| 39 | + * predicates. It handles both leaf-level conditions (like equals, greater than) and compound |
| 40 | + * conditions (AND, OR). |
| 41 | + */ |
| 42 | +public class FlussToPaimonPredicateConverter implements PredicateVisitor<Predicate> { |
| 43 | + |
| 44 | + private final PredicateBuilder builder; |
| 45 | + private final LeafFunctionConverter converter = new LeafFunctionConverter(); |
| 46 | + |
| 47 | + public FlussToPaimonPredicateConverter(RowType rowType) { |
| 48 | + this.builder = new PredicateBuilder(rowType); |
| 49 | + } |
| 50 | + |
| 51 | + public static Optional<Predicate> convert( |
| 52 | + RowType rowType, com.alibaba.fluss.predicate.Predicate flussPredicate) { |
| 53 | + try { |
| 54 | + return Optional.of(flussPredicate.visit(new FlussToPaimonPredicateConverter(rowType))); |
| 55 | + } catch (UnsupportedOperationException e) { |
| 56 | + return Optional.empty(); |
| 57 | + } |
| 58 | + } |
| 59 | + |
| 60 | + @Override |
| 61 | + public Predicate visit(LeafPredicate predicate) { |
| 62 | + // Delegate the conversion of the specific function to a dedicated visitor. |
| 63 | + // This avoids a long chain of 'if-instanceof' checks. |
| 64 | + return predicate.visit(converter); |
| 65 | + } |
| 66 | + |
| 67 | + @Override |
| 68 | + public Predicate visit(CompoundPredicate predicate) { |
| 69 | + List<Predicate> children = |
| 70 | + predicate.children().stream().map(p -> p.visit(this)).collect(Collectors.toList()); |
| 71 | + CompoundPredicate.Function function = predicate.function(); |
| 72 | + if (function instanceof And) { |
| 73 | + return PredicateBuilder.and(children); |
| 74 | + } else if (function instanceof Or) { |
| 75 | + return PredicateBuilder.or(children); |
| 76 | + } else { |
| 77 | + throw new UnsupportedOperationException( |
| 78 | + "Unsupported fluss compound predicate function: " + predicate.function()); |
| 79 | + } |
| 80 | + } |
| 81 | + |
| 82 | + /** |
| 83 | + * A visitor that implements the logic to convert each type of {@link |
| 84 | + * com.alibaba.fluss.predicate.LeafFunction} to a Paimon {@link Predicate}. |
| 85 | + */ |
| 86 | + private class LeafFunctionConverter implements FunctionVisitor<Predicate> { |
| 87 | + |
| 88 | + @Override |
| 89 | + public Predicate visitIsNotNull(FieldRef fieldRef) { |
| 90 | + return builder.isNotNull(fieldRef.index()); |
| 91 | + } |
| 92 | + |
| 93 | + @Override |
| 94 | + public Predicate visitIsNull(FieldRef fieldRef) { |
| 95 | + return builder.isNull(fieldRef.index()); |
| 96 | + } |
| 97 | + |
| 98 | + @Override |
| 99 | + public Predicate visitStartsWith(FieldRef fieldRef, Object literal) { |
| 100 | + return builder.startsWith(fieldRef.index(), literal); |
| 101 | + } |
| 102 | + |
| 103 | + @Override |
| 104 | + public Predicate visitEndsWith(FieldRef fieldRef, Object literal) { |
| 105 | + return builder.endsWith(fieldRef.index(), literal); |
| 106 | + } |
| 107 | + |
| 108 | + @Override |
| 109 | + public Predicate visitContains(FieldRef fieldRef, Object literal) { |
| 110 | + return builder.contains(fieldRef.index(), literal); |
| 111 | + } |
| 112 | + |
| 113 | + @Override |
| 114 | + public Predicate visitLessThan(FieldRef fieldRef, Object literal) { |
| 115 | + return builder.lessThan(fieldRef.index(), literal); |
| 116 | + } |
| 117 | + |
| 118 | + @Override |
| 119 | + public Predicate visitGreaterOrEqual(FieldRef fieldRef, Object literal) { |
| 120 | + return builder.greaterOrEqual(fieldRef.index(), literal); |
| 121 | + } |
| 122 | + |
| 123 | + @Override |
| 124 | + public Predicate visitNotEqual(FieldRef fieldRef, Object literal) { |
| 125 | + return builder.notEqual(fieldRef.index(), literal); |
| 126 | + } |
| 127 | + |
| 128 | + @Override |
| 129 | + public Predicate visitLessOrEqual(FieldRef fieldRef, Object literal) { |
| 130 | + return builder.lessOrEqual(fieldRef.index(), literal); |
| 131 | + } |
| 132 | + |
| 133 | + @Override |
| 134 | + public Predicate visitEqual(FieldRef fieldRef, Object literal) { |
| 135 | + return builder.equal(fieldRef.index(), literal); |
| 136 | + } |
| 137 | + |
| 138 | + @Override |
| 139 | + public Predicate visitGreaterThan(FieldRef fieldRef, Object literal) { |
| 140 | + return builder.greaterThan(fieldRef.index(), literal); |
| 141 | + } |
| 142 | + |
| 143 | + @Override |
| 144 | + public Predicate visitIn(FieldRef fieldRef, List<Object> literals) { |
| 145 | + return builder.in(fieldRef.index(), literals); |
| 146 | + } |
| 147 | + |
| 148 | + @Override |
| 149 | + public Predicate visitNotIn(FieldRef fieldRef, List<Object> literals) { |
| 150 | + return builder.notIn(fieldRef.index(), literals); |
| 151 | + } |
| 152 | + |
| 153 | + @Override |
| 154 | + public Predicate visitAnd(List<Predicate> children) { |
| 155 | + // shouldn't come to here |
| 156 | + throw new UnsupportedOperationException("Unsupported visitAnd method."); |
| 157 | + } |
| 158 | + |
| 159 | + @Override |
| 160 | + public Predicate visitOr(List<Predicate> children) { |
| 161 | + // shouldn't come to here |
| 162 | + throw new UnsupportedOperationException("Unsupported visitOr method."); |
| 163 | + } |
| 164 | + } |
| 165 | +} |
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