org.neo4j.cypher.internal.logical.plans.PartialTop.scala Maven / Gradle / Ivy

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/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.cypher.internal.logical.plans

import org.neo4j.cypher.internal.expressions.Expression
import org.neo4j.cypher.internal.util.attribution.IdGen

/*
 * Consume rows that are already sorted by `alreadySortedPrefix`. Sort, in chunks, by `stillToSortSuffix`.
 * Only retain the first 'limit' rows, which are produced once the TopTable is full and the current
 * chunk is read completely.
 */
case class PartialTop(override val source: LogicalPlan,
                      alreadySortedPrefix: Seq[ColumnOrder],
                      stillToSortSuffix: Seq[ColumnOrder],
                      limit: Expression,
                      skipSortingPrefixLength: Option[Expression] = None)(implicit idGen: IdGen) extends LogicalUnaryPlan(idGen) with LimitingLogicalPlan {
  override def withLhs(newLHS: LogicalPlan)(idGen: IdGen): LogicalUnaryPlan = copy(source = newLHS)(idGen)

  override val availableSymbols: Set[String] = source.availableSymbols
}