be/src/exprs/expr-value.h

// 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.

#ifndef IMPALA_EXPRS_EXPR_VALUE_H
#define IMPALA_EXPRS_EXPR_VALUE_H

#include "runtime/collection-value.h"
#include "runtime/date-value.h"
#include "runtime/decimal-value.h"
#include "runtime/string-value.inline.h"
#include "runtime/timestamp-value.h"
#include "udf/udf-internal.h"
#include "util/decimal-constants.h"

namespace impala {

/// The materialized value returned by ScalarExprEvaluator::GetValue().
struct ExprValue {
  bool bool_val;
  int8_t tinyint_val;
  int16_t smallint_val;
  int32_t int_val;
  int64_t bigint_val;
  float float_val;
  double double_val;
  StringValue string_val;
  TimestampValue timestamp_val;
  Decimal4Value decimal4_val;
  Decimal8Value decimal8_val;
  Decimal16Value decimal16_val;
  CollectionValue collection_val;
  impala_udf::StructVal struct_val;
  impala_udf::VariantVal variant_val;
  DateValue date_val;

  ExprValue()
    : bool_val(false),
      tinyint_val(0),
      smallint_val(0),
      int_val(0),
      bigint_val(0),
      float_val(0.0),
      double_val(0.0),
      string_val(NULL, 0),
      timestamp_val(),
      decimal4_val(),
      decimal8_val(),
      decimal16_val(),
      collection_val(),
      struct_val(),
      variant_val(),
      date_val(0) {
  }

  ExprValue(bool v) : bool_val(v) {}
  ExprValue(int8_t v) : tinyint_val(v) {}
  ExprValue(int16_t v) : smallint_val(v) {}
  ExprValue(int32_t v) : int_val(v) {}
  ExprValue(int64_t v) : bigint_val(v) {}
  ExprValue(float v) : float_val(v) {}
  ExprValue(double v) : double_val(v) {}

  void Init(const std::string& str) {
    string_data = str;
    string_val.Assign(string_data.data(), string_data.size());
  }

  /// Sets the value for type to '0' and returns a pointer to the data
  void* SetToZero(const ColumnType& type) {
    switch (type.type) {
      case TYPE_NULL:
        return NULL;
      case TYPE_BOOLEAN:
        bool_val = false;
        return &bool_val;
      case TYPE_TINYINT:
        tinyint_val = 0;
        return &tinyint_val;
      case TYPE_SMALLINT:
        smallint_val = 0;
        return &smallint_val;
      case TYPE_INT:
        int_val = 0;
        return &int_val;
      case TYPE_BIGINT:
        bigint_val = 0;
        return &bigint_val;
      case TYPE_FLOAT:
        float_val = 0;
        return &float_val;
      case TYPE_DOUBLE:
        double_val = 0;
        return &double_val;
      case TYPE_DATE:
        date_val = DateValue(0);
        return &date_val;
      default:
        DCHECK(false);
        return NULL;
    }
  }

  /// Sets the value for type to min and returns a pointer to the data
  void* SetToMin(const ColumnType& type) {
    switch (type.type) {
      case TYPE_NULL:
        return NULL;
      case TYPE_BOOLEAN:
        bool_val = false;
        return &bool_val;
      case TYPE_TINYINT:
        tinyint_val = std::numeric_limits<int8_t>::min();
        return &tinyint_val;
      case TYPE_SMALLINT:
        smallint_val = std::numeric_limits<int16_t>::min();
        return &smallint_val;
      case TYPE_INT:
        int_val = std::numeric_limits<int32_t>::min();
        return &int_val;
      case TYPE_BIGINT:
        bigint_val = std::numeric_limits<int64_t>::min();
        return &bigint_val;
      case TYPE_DECIMAL:
        switch (type.GetByteSize()) {
          case 4:
            decimal4_val = -MAX_UNSCALED_DECIMAL4;
            return &decimal4_val;
          case 8:
            decimal8_val = -MAX_UNSCALED_DECIMAL8;
            return &decimal8_val;
          case 16:
            decimal16_val = -MAX_UNSCALED_DECIMAL16;
            return &decimal16_val;
        }
      case TYPE_FLOAT:
        // For floats and doubles, numeric_limits::min() is the smallest positive
        // representable value.
        float_val = -std::numeric_limits<float>::infinity();
        return &float_val;
      case TYPE_DOUBLE:
        double_val = -std::numeric_limits<double>::infinity();
        return &double_val;
      case TYPE_DATE:
        date_val = DateValue::MIN_DATE;
        return &date_val;
      default:
        DCHECK(false);
        return NULL;
    }
  }

  /// Sets the value for type to max and returns a pointer to the data
  void* SetToMax(const ColumnType& type) {
    switch (type.type) {
      case TYPE_NULL:
        return NULL;
      case TYPE_BOOLEAN:
        bool_val = true;
        return &bool_val;
      case TYPE_TINYINT:
        tinyint_val = std::numeric_limits<int8_t>::max();
        return &tinyint_val;
      case TYPE_SMALLINT:
        smallint_val = std::numeric_limits<int16_t>::max();
        return &smallint_val;
      case TYPE_INT:
        int_val = std::numeric_limits<int32_t>::max();
        return &int_val;
      case TYPE_BIGINT:
        bigint_val = std::numeric_limits<int64_t>::max();
        return &bigint_val;
      case TYPE_DECIMAL:
        switch (type.GetByteSize()) {
          case 4:
            decimal4_val = MAX_UNSCALED_DECIMAL4;
            return &decimal4_val;
          case 8:
            decimal8_val = MAX_UNSCALED_DECIMAL8;
            return &decimal8_val;
          case 16:
            decimal16_val = MAX_UNSCALED_DECIMAL16;
            return &decimal16_val;
        }
      case TYPE_FLOAT:
        float_val = std::numeric_limits<float>::infinity();
        return &float_val;
      case TYPE_DOUBLE:
        double_val = std::numeric_limits<double>::infinity();
        return &double_val;
      case TYPE_DATE:
        date_val = DateValue::MAX_DATE;
        return &date_val;
      default:
        DCHECK(false);
        return NULL;
    }
  }

  void* SetToAnyVal(impala_udf::AnyVal* v, const ColumnType& type) {
    if (v->is_null) return nullptr;
    switch (type.type) {
      case TYPE_BOOLEAN:
        bool_val = ((impala_udf::BooleanVal*)v)->val;
        return &bool_val;
      case TYPE_TINYINT:
        tinyint_val = ((impala_udf::TinyIntVal*)v)->val;
        return &tinyint_val;
      case TYPE_SMALLINT:
        smallint_val = ((impala_udf::SmallIntVal*)v)->val;
        return &smallint_val;
      case TYPE_INT:
        int_val = ((impala_udf::IntVal*)v)->val;
        return &int_val;
      case TYPE_BIGINT:
        bigint_val = ((impala_udf::BigIntVal*)v)->val;
        return &bigint_val;
      case TYPE_FLOAT:
        float_val = ((impala_udf::FloatVal*)v)->val;
        return &float_val;
      case TYPE_DOUBLE:
        double_val = ((impala_udf::DoubleVal*)v)->val;
        return &double_val;
      case TYPE_TIMESTAMP:
        timestamp_val = TimestampValue::FromTimestampVal(*((impala_udf::TimestampVal*)v));
        return &timestamp_val;
      case TYPE_DATE:
        date_val = DateValue(((impala_udf::DateVal*)v)->val);
        return &date_val;
      case TYPE_STRING:
      case TYPE_VARCHAR:
        string_val = StringValue::FromStringVal(*((impala_udf::StringVal*)v));
        return &string_val;
      default:
        DCHECK(false) << "NYI";
        return nullptr;
    }
  }

  /// Returns whether the two ExprValue's are equal if they both have the given type.
  bool EqualsWithType(const ExprValue& other, const ColumnType& type) const {
    switch (type.type) {
      case INVALID_TYPE:
        return true;
      case TYPE_NULL:
        return true;
      case TYPE_BOOLEAN:
        return bool_val == other.bool_val;
      case TYPE_TINYINT:
        return tinyint_val == other.tinyint_val;
      case TYPE_SMALLINT:
        return smallint_val == other.smallint_val;
      case TYPE_INT:
        return int_val == other.int_val;
      case TYPE_BIGINT:
        return bigint_val ==  other.bigint_val;
      case TYPE_FLOAT:
        return float_val == other.float_val;
      case TYPE_DOUBLE:
        return double_val == other.double_val;
      case TYPE_TIMESTAMP:
        return timestamp_val == other.timestamp_val;
      case TYPE_STRING:
      case TYPE_CHAR:
      case TYPE_VARCHAR:
        return string_val == other.string_val;
      case TYPE_DECIMAL:
        switch (type.GetByteSize()) {
          case 4:
            return decimal4_val == other.decimal4_val;
          case 8:
            return decimal8_val == other.decimal8_val;
          case 16:
            return decimal16_val == other.decimal16_val;
        }
      case TYPE_DATE:
        return date_val == other.date_val;
      case TYPE_STRUCT:
      case TYPE_ARRAY:
      case TYPE_MAP:
      case TYPE_DATETIME:               // Not implemented
      case TYPE_BINARY:                 // Not implemented
      case TYPE_FIXED_UDA_INTERMEDIATE: // Only used internally
      default:
        DCHECK(false) << "ExprValue equality unimplemented for " << type << ".";
        return false;
    }

  }

 private:
  std::string string_data; // Stores the data for string_val if necessary.

  DISALLOW_COPY_AND_ASSIGN(ExprValue);
};

}

#endif