thriftserver/server/src/main/java/org/apache/hive/service/cli/operation/GetTypeInfoOperation.java

/*
 * 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 under the License.
 */

package org.apache.hive.service.cli.operation;

import java.util.ArrayList;
import java.util.Arrays;

import org.apache.hadoop.hive.serde2.thrift.Type;
import org.apache.hive.service.cli.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * GetTypeInfoOperation.
 *
 */
public class GetTypeInfoOperation extends MetadataOperation {

  private static final Logger LOG = LoggerFactory.getLogger(GetTypeInfoOperation.class.getName());

  private final static TableSchema RESULT_SET_SCHEMA = new TableSchema()
  .addPrimitiveColumn("TYPE_NAME", Type.STRING_TYPE,
      "Type name")
  .addPrimitiveColumn("DATA_TYPE", Type.INT_TYPE,
      "SQL data type from java.sql.Types")
  .addPrimitiveColumn("PRECISION", Type.INT_TYPE,
      "Maximum precision")
  .addPrimitiveColumn("LITERAL_PREFIX", Type.STRING_TYPE,
      "Prefix used to quote a literal (may be null)")
  .addPrimitiveColumn("LITERAL_SUFFIX", Type.STRING_TYPE,
      "Suffix used to quote a literal (may be null)")
  .addPrimitiveColumn("CREATE_PARAMS", Type.STRING_TYPE,
      "Parameters used in creating the type (may be null)")
  .addPrimitiveColumn("NULLABLE", Type.SMALLINT_TYPE,
      "Can you use NULL for this type")
  .addPrimitiveColumn("CASE_SENSITIVE", Type.BOOLEAN_TYPE,
      "Is it case sensitive")
  .addPrimitiveColumn("SEARCHABLE", Type.SMALLINT_TYPE,
      "Can you use \"WHERE\" based on this type")
  .addPrimitiveColumn("UNSIGNED_ATTRIBUTE", Type.BOOLEAN_TYPE,
      "Is it unsigned")
  .addPrimitiveColumn("FIXED_PREC_SCALE", Type.BOOLEAN_TYPE,
      "Can it be a money value")
  .addPrimitiveColumn("AUTO_INCREMENT", Type.BOOLEAN_TYPE,
      "Can it be used for an auto-increment value")
  .addPrimitiveColumn("LOCAL_TYPE_NAME", Type.STRING_TYPE,
      "Localized version of type name (may be null)")
  .addPrimitiveColumn("MINIMUM_SCALE", Type.SMALLINT_TYPE,
      "Minimum scale supported")
  .addPrimitiveColumn("MAXIMUM_SCALE", Type.SMALLINT_TYPE,
      "Maximum scale supported")
  .addPrimitiveColumn("SQL_DATA_TYPE", Type.INT_TYPE,
      "Unused")
  .addPrimitiveColumn("SQL_DATETIME_SUB", Type.INT_TYPE,
      "Unused")
  .addPrimitiveColumn("NUM_PREC_RADIX", Type.INT_TYPE,
      "Usually 2 or 10");

  private final RowSet rowSet;

  public GetTypeInfoOperation(SessionHandle sessionHandle) {
    super(sessionHandle, OperationType.GET_TYPE_INFO);
    rowSet = RowSetFactory.create(RESULT_SET_SCHEMA, getProtocolVersion(), false);
    LOG.info("Starting GetTypeInfoOperation");
  }

  @Override
  public void runInternal() throws HiveSQLException {
    setState(OperationState.RUNNING);
    LOG.info("Fetching type info metadata");
    try {
      for (Type type : Type.values()) {
        Object[] rowData = new Object[] {
            type.getName(), // TYPE_NAME
            type.toJavaSQLType(), // DATA_TYPE
            type.getMaxPrecision(), // PRECISION
            type.getLiteralPrefix(), // LITERAL_PREFIX
            type.getLiteralSuffix(), // LITERAL_SUFFIX
            type.getCreateParams(), // CREATE_PARAMS
            type.getNullable(), // NULLABLE
            type.isCaseSensitive(), // CASE_SENSITIVE
            type.getSearchable(), // SEARCHABLE
            type.isUnsignedAttribute(), // UNSIGNED_ATTRIBUTE
            type.isFixedPrecScale(), // FIXED_PREC_SCALE
            type.isAutoIncrement(), // AUTO_INCREMENT
            type.getLocalizedName(), // LOCAL_TYPE_NAME
            type.getMinimumScale(), // MINIMUM_SCALE
            type.getMaximumScale(), // MAXIMUM_SCALE
            null, // SQL_DATA_TYPE, unused
            null, // SQL_DATETIME_SUB, unused
            type.getNumPrecRadix() //NUM_PREC_RADIX
        };
        rowSet.addRow(rowData);
        if (LOG.isDebugEnabled()) {
          String debugMessage = getDebugMessage("type info", RESULT_SET_SCHEMA);
          LOG.debug(debugMessage, rowData);
        }
      }
      if (LOG.isDebugEnabled() && rowSet.numRows() == 0) {
        LOG.debug("No type info metadata has been returned.");
      }
      setState(OperationState.FINISHED);
      LOG.info("Fetching type info metadata has been successfully finished");
    } catch (Exception e) {
      setState(OperationState.ERROR);
      throw new HiveSQLException(e);
    }
  }

  /* (non-Javadoc)
   * @see org.apache.hive.service.cli.Operation#getResultSetSchema()
   */
  @Override
  public TableSchema getResultSetSchema() throws HiveSQLException {
    assertState(new ArrayList<OperationState>(Arrays.asList(OperationState.FINISHED)));
    return RESULT_SET_SCHEMA;
  }

  /* (non-Javadoc)
   * @see org.apache.hive.service.cli.Operation#getNextRowSet(org.apache.hive.service.cli.FetchOrientation, long)
   */
  @Override
  public RowSet getNextRowSet(FetchOrientation orientation, long maxRows) throws HiveSQLException {
    assertState(new ArrayList<OperationState>(Arrays.asList(OperationState.FINISHED)));
    validateDefaultFetchOrientation(orientation);
    if (orientation.equals(FetchOrientation.FETCH_FIRST)) {
      rowSet.setStartOffset(0);
    }
    return rowSet.extractSubset((int)maxRows);
  }
}