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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
//
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package org.apache.impala.planner;

import com.google.common.base.Preconditions;

/**
 * Utility class to help set up the various parameters of a ResourceProfile.
 */
public class ResourceProfileBuilder {

  // Must be set by caller.
  private long memEstimateBytes_ = -1;

  // Assume no reservation is used unless the caller explicitly sets it.
  private long minMemReservationBytes_ = 0;
  private long maxMemReservationBytes_ = 0;

  // The spillable buffer size is only set by plan nodes that use it.
  private long spillableBufferBytes_= -1;

  // Must be set if spillableBufferBytes_ is set.
  private long maxRowBufferBytes_= -1;

  // Defaults to zero, because most ExecNodes do not create additional threads.
  private long threadReservation_ = 0;

  public ResourceProfileBuilder setMemEstimateBytes(long memEstimateBytes) {
    memEstimateBytes_ = memEstimateBytes;
    return this;
  }

  /**
   * Sets the minimum memory reservation and an unbounded maximum memory reservation.
   */
  public ResourceProfileBuilder setMinMemReservationBytes(long minMemReservationBytes) {
    minMemReservationBytes_ = minMemReservationBytes;
    if (maxMemReservationBytes_ == 0) maxMemReservationBytes_ = Long.MAX_VALUE;
    return this;
  }

  public ResourceProfileBuilder setMaxMemReservationBytes(long maxMemReservationBytes) {
    maxMemReservationBytes_ = maxMemReservationBytes;
    return this;
  }

  public ResourceProfileBuilder setSpillableBufferBytes(long spillableBufferBytes) {
    spillableBufferBytes_ = spillableBufferBytes;
    return this;
  }

  public ResourceProfileBuilder setMaxRowBufferBytes(long maxRowBufferBytes) {
    maxRowBufferBytes_ = maxRowBufferBytes;
    return this;
  }

  public ResourceProfileBuilder setThreadReservation(long threadReservation) {
    threadReservation_ = threadReservation;
    return this;
  }

  ResourceProfile build() {
    Preconditions.checkState(memEstimateBytes_ >= 0, "Mem estimate must be set");
    return new ResourceProfile(true, memEstimateBytes_, minMemReservationBytes_,
        maxMemReservationBytes_, spillableBufferBytes_, maxRowBufferBytes_,
        threadReservation_);
  }
}