flink-libraries/flink-table/src/main/scala/org/apache/flink/table/plan/util/PartitionPredicateExtractor.scala

/*
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 * distributed with this work for additional information
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 * 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
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package org.apache.flink.table.plan.util

import org.apache.flink.table.expressions.{Expression, ResolvedFieldReference}

object PartitionPredicateExtractor {

  /**
    * Extract partition predicate from filter condition.
    *
    * @param predicates          Filter condition.
    * @param partitionFieldNames Partition field names.
    * @return Partition predicates and non-partition predicates.
    */
  def extractPartitionPredicates(
    predicates: Array[Expression],
    partitionFieldNames: Array[String]): (Array[Expression], Array[Expression]) = {

    predicates.partition(postOrderVisit(_, partitionFieldNames))
  }

  private def postOrderVisit(e: Expression, partitionFieldNames: Array[String]): Boolean = {
    e match {
      case r@ResolvedFieldReference(name, _) => partitionFieldNames.contains(name)
      case _ => e.children.forall(postOrderVisit(_, partitionFieldNames))
    }
  }
}