fe/src/main/java/org/apache/impala/analysis/IcebergPartitionTransform.java

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//   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.impala.analysis;

import org.apache.impala.common.AnalysisException;
import org.apache.impala.thrift.TIcebergPartitionTransform;
import org.apache.impala.thrift.TIcebergPartitionTransformType;

/**
 * Represents the partition transform part of an Iceberg partition field.
*/
public class IcebergPartitionTransform extends StmtNode {

    // Stores the transform type such as HOUR, YEAR, etc.
    private TIcebergPartitionTransformType transformType_;

    // Stores the parameter of BUCKET or TRUNCATE partition transforms (numBuckets,
    // width respectively). This is null for partition transforms that don't have a
    // parameter.
    private Integer transformParam_;

    // Constructor for parameterless partition transforms.
    public IcebergPartitionTransform(TIcebergPartitionTransformType transformType) {
        this(transformType, null);
    }

    public IcebergPartitionTransform(TIcebergPartitionTransformType transformType,
        Integer transformParam) {
      transformType_ = transformType;
      transformParam_ = transformParam;
    }

    public TIcebergPartitionTransformType getTransformType() {
      return transformType_;
    }

    public Integer getTransformParam() {
      return transformParam_;
    }

    @Override
    public void analyze(Analyzer analyzer) throws AnalysisException {
      if (transformType_ == TIcebergPartitionTransformType.BUCKET ||
          transformType_ == TIcebergPartitionTransformType.TRUNCATE) {
        if (transformParam_ == null) {
          throw new AnalysisException("BUCKET and TRUNCATE partition transforms should " +
              "have a parameter.");
        }
        if (transformParam_ <= 0) {
          throw new AnalysisException("The parameter of a partition transform should " +
              "be greater than zero.");
        }
      } else {
        if (transformParam_ != null) {
          throw new AnalysisException("Only BUCKET and TRUNCATE partition transforms " +
              "accept a parameter.");
        }
      }
      return;
    }

  @Override
  public final String toSql() {
    return toSql(ToSqlOptions.DEFAULT);
  }

  @Override
  public String toSql(ToSqlOptions options) {
    StringBuilder builder = new StringBuilder();
    builder.append(transformType_.toString());
    if (transformParam_ != null) builder.append(" " + transformParam_.toString());
    return builder.toString();
  }

  public TIcebergPartitionTransform toThrift() {
    TIcebergPartitionTransform transform = new TIcebergPartitionTransform();
    transform.setTransform_type(transformType_);
    if (transformParam_ != null) transform.setTransform_param(transformParam_);
    return transform;
  }
}