rubenada commented on a change in pull request #2080: URL: https://github.com/apache/calcite/pull/2080#discussion_r460160253
########## File path: core/src/main/java/org/apache/calcite/adapter/enumerable/EnumerableTopNHeapSort.java ########## @@ -0,0 +1,162 @@ +/* + * 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.calcite.adapter.enumerable; + +import org.apache.calcite.DataContext; +import org.apache.calcite.linq4j.tree.BlockBuilder; +import org.apache.calcite.linq4j.tree.Expression; +import org.apache.calcite.linq4j.tree.Expressions; +import org.apache.calcite.plan.RelOptCluster; +import org.apache.calcite.plan.RelOptCost; +import org.apache.calcite.plan.RelOptPlanner; +import org.apache.calcite.plan.RelTraitSet; +import org.apache.calcite.rel.RelCollation; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Sort; +import org.apache.calcite.rel.metadata.RelMetadataQuery; +import org.apache.calcite.rex.RexDynamicParam; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.util.BuiltInMethod; +import org.apache.calcite.util.Pair; +import org.apache.calcite.util.Util; + +/** + * Implementation of {@link org.apache.calcite.rel.core.Sort} in + * {@link org.apache.calcite.adapter.enumerable.EnumerableConvention enumerable calling convention}. + * It also deals with the offset and the limit. + */ +public class EnumerableTopNHeapSort extends Sort implements EnumerableRel { + + /** + * Creates an EnumerableTopNHeapSort. + * + * <p>Use {@link #create} unless you know what you're doing. + */ + public EnumerableTopNHeapSort( + RelOptCluster cluster, + RelTraitSet traitSet, + RelNode input, + RelCollation collation, + RexNode offset, + RexNode fetch) { + super(cluster, traitSet, input, collation, offset, fetch); + assert this.getConvention() instanceof EnumerableConvention; + assert this.getConvention() == input.getConvention(); + assert fetch != null; + } + + /** Creates an EnumerableTopNHeapSort. */ + public static EnumerableTopNHeapSort create( + RelNode child, + RelCollation collation, + RexNode offset, + RexNode fetch) { + final RelOptCluster cluster = child.getCluster(); + final RelTraitSet traitSet = cluster.traitSetOf(EnumerableConvention.INSTANCE).replace( + collation); + return new EnumerableTopNHeapSort(cluster, traitSet, child, collation, offset, fetch); + } + + private static Expression getExpression(RexNode offset) { + if (offset instanceof RexDynamicParam) { + final RexDynamicParam param = (RexDynamicParam) offset; + return Expressions.convert_( + Expressions.call( + DataContext.ROOT, + BuiltInMethod.DATA_CONTEXT_GET.method, + Expressions.constant("?" + param.getIndex())), Integer.class); + } else { + return Expressions.constant(Integer.valueOf(RexLiteral.intValue(offset))); + } + } + + @Override public EnumerableTopNHeapSort copy( + RelTraitSet traitSet, + RelNode newInput, + RelCollation newCollation, + RexNode offset, + RexNode fetch) { + if (fetch == null) { + return null; + } + + return new EnumerableTopNHeapSort( + this.getCluster(), + traitSet, + newInput, + newCollation, + offset, + fetch); + } + + @Override public Result implement(EnumerableRelImplementor implementor, Prefer pref) { + final BlockBuilder builder = new BlockBuilder(); + final EnumerableRel child = (EnumerableRel) this.getInput(); + final Result result = implementor.visitChild(this, 0, child, pref); + final PhysType physType = PhysTypeImpl.of( + implementor.getTypeFactory(), + this.getRowType(), + result.format); + Expression childExp = builder.append("child", result.block); + + PhysType inputPhysType = result.physType; + final Pair<Expression, Expression> pair = + inputPhysType.generateCollationKey(this.collation.getFieldCollations()); + + Expression fetchVal; + if (this.fetch == null) { Review comment: Can fetch be actually null? I think it is / should be forbidden in the constructor ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected]
