/*
 * 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
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 */

package org.apache.spark.sql.hudi.blob

import org.apache.spark.sql.catalyst.expressions.{Attribute, AttributeReference, AttributeSet, Expression}
import org.apache.spark.sql.catalyst.plans.logical.{LogicalPlan, UnaryNode}
import org.apache.spark.sql.hudi.blob.BatchedBlobReader.DATA_COL
import org.apache.spark.sql.types.BinaryType

/**
 * Logical plan node for batched blob reading.
 *
 * Created by [[ReadBlobRule]] when `read_blob()` is detected in queries.
 * Converted to [[BatchedBlobReadExec]] by [[BatchedBlobReaderStrategy]] during physical planning.
 *
 * @param child Child logical plan
 * @param blobAttr The blob column attribute to read from
 * @param dataAttr The output attribute for resolved blob data
 */
case class BatchedBlobRead(
                            child: LogicalPlan,
                            blobAttr: Attribute,
                            dataAttr: AttributeReference =
                            AttributeReference(DATA_COL, BinaryType, nullable = true)())
  extends UnaryNode {

  override def output: Seq[Attribute] = child.output :+ dataAttr

  override protected def withNewChildInternal(newChild: LogicalPlan): LogicalPlan = {
    copy(child = newChild)
  }

  override def producedAttributes: AttributeSet = AttributeSet(dataAttr)

}
