core/sql/exp/exp_interval.cpp

/**********************************************************************
// @@@ START COPYRIGHT @@@
//
// 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.
//
// @@@ END COPYRIGHT @@@
**********************************************************************/
/* -*-C++-*-
 *****************************************************************************
 *
 * File:         exp_interval.C
 * Description:  Interval Type
 *
 *
 * Created:      8/20/96
 * Language:     C++
 *
 *
 *
 *
 *****************************************************************************
 */

#include "Platform.h"


#include "exp_interval.h"

// ***********************************************************************
//
// getIntervalStartField returns the start field for a given interval
// FS datatype.  If the given FS datatype is invalid, the routine returns
// a status of -1.  Otherwise, it returns a status of 0.
//
// ***********************************************************************

short ExpInterval::getIntervalStartField(Lng32 fsDatatype,
					 rec_datetime_field &startField)
{
  switch (fsDatatype) {
  case REC_INT_YEAR:
  case REC_INT_YEAR_MONTH:
    startField = REC_DATE_YEAR;
    break;
  case REC_INT_MONTH:
    startField = REC_DATE_MONTH;
    break;
  case REC_INT_DAY:
  case REC_INT_DAY_HOUR:
  case REC_INT_DAY_MINUTE:
  case REC_INT_DAY_SECOND:
    startField = REC_DATE_DAY;
    break;
  case REC_INT_HOUR:
  case REC_INT_HOUR_MINUTE:
  case REC_INT_HOUR_SECOND:
    startField = REC_DATE_HOUR;
    break;
  case REC_INT_MINUTE:
  case REC_INT_MINUTE_SECOND:
    startField = REC_DATE_MINUTE;
    break;
  case REC_INT_SECOND:
    startField = REC_DATE_SECOND;
    break;
  default:
    return -1;
  }
  return 0;
} // getIntervalStartField

// ***********************************************************************
//
// getIntervalEndField returns the end field for a given interval
// FS datatype.  If the given FS datatype is invalid, the routine returns
// a status of -1.  Otherwise, it returns a status of 0.
//
// ***********************************************************************

short ExpInterval::getIntervalEndField(Lng32 fsDatatype,
				       rec_datetime_field &endField)
{
  switch (fsDatatype) {
  case REC_INT_YEAR:
    endField = REC_DATE_YEAR;
    break;
  case REC_INT_MONTH:
  case REC_INT_YEAR_MONTH:
    endField = REC_DATE_MONTH;
    break;
  case REC_INT_DAY:
    endField = REC_DATE_DAY;
    break;
  case REC_INT_HOUR:
  case REC_INT_DAY_HOUR:
    endField = REC_DATE_HOUR;
    break;
  case REC_INT_MINUTE:
  case REC_INT_HOUR_MINUTE:
  case REC_INT_DAY_MINUTE:
    endField = REC_DATE_MINUTE;
    break;
  case REC_INT_SECOND:
  case REC_INT_MINUTE_SECOND:
  case REC_INT_HOUR_SECOND:
  case REC_INT_DAY_SECOND:
    endField = REC_DATE_SECOND;
    break;
  default:
    return -1;
  }
  return 0;
} // getIntervalEndField

static const Int32 IntervalFieldStringSize = 3;	// punc plus two digits

Lng32 ExpInterval::getDisplaySize(Lng32 fsDatatype,
				 short leadingPrecision,
				 short fractionPrecision)
{
  size_t result;

  rec_datetime_field startField, endField;

  getIntervalStartField(fsDatatype, startField);
  getIntervalEndField(fsDatatype, endField);

  // 1 for sign
  if (startField == REC_DATE_FRACTION_MP)
    {
      result = 1 + leadingPrecision;
    }
  else
    {
      result = 1 +
	leadingPrecision +
	IntervalFieldStringSize * (endField - startField);
      if (fractionPrecision)
	result += fractionPrecision + 1;       // 1 for "."
    }
  return result;
}