geode-core/src/main/java/org/apache/geode/cache/query/internal/CompiledAggregateFunction.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.
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package org.apache.geode.cache.query.internal;

import org.apache.geode.cache.query.AmbiguousNameException;
import org.apache.geode.cache.query.FunctionDomainException;
import org.apache.geode.cache.query.NameResolutionException;
import org.apache.geode.cache.query.QueryInvocationTargetException;
import org.apache.geode.cache.query.TypeMismatchException;
import org.apache.geode.cache.query.internal.aggregate.Avg;
import org.apache.geode.cache.query.internal.aggregate.AvgBucketNode;
import org.apache.geode.cache.query.internal.aggregate.AvgDistinct;
import org.apache.geode.cache.query.internal.aggregate.AvgDistinctPRQueryNode;
import org.apache.geode.cache.query.internal.aggregate.AvgPRQueryNode;
import org.apache.geode.cache.query.internal.aggregate.Count;
import org.apache.geode.cache.query.internal.aggregate.CountDistinct;
import org.apache.geode.cache.query.internal.aggregate.CountDistinctPRQueryNode;
import org.apache.geode.cache.query.internal.aggregate.CountPRQueryNode;
import org.apache.geode.cache.query.internal.aggregate.DistinctAggregator;
import org.apache.geode.cache.query.internal.aggregate.MaxMin;
import org.apache.geode.cache.query.internal.aggregate.Sum;
import org.apache.geode.cache.query.internal.aggregate.SumDistinct;
import org.apache.geode.cache.query.internal.aggregate.SumDistinctPRQueryNode;
import org.apache.geode.cache.query.internal.parse.OQLLexerTokenTypes;
import org.apache.geode.cache.query.internal.types.ObjectTypeImpl;
import org.apache.geode.cache.query.types.ObjectType;

public class CompiledAggregateFunction extends AbstractCompiledValue {

  private final CompiledValue expr;
  private final int aggFuncType;
  private final boolean distinctOnly;

  public CompiledAggregateFunction(CompiledValue expr, int aggFunc) {
    this(expr, aggFunc, false);
  }

  public CompiledAggregateFunction(CompiledValue expr, int aggFunc, boolean distinctOnly) {
    this.expr = expr;
    this.aggFuncType = aggFunc;
    this.distinctOnly = distinctOnly;
  }

  @Override
  public int getType() {

    return AGG_FUNC;
  }

  @Override
  public Object evaluate(ExecutionContext context) throws FunctionDomainException,
      TypeMismatchException, NameResolutionException, QueryInvocationTargetException {
    boolean isPRQueryNode = context.getIsPRQueryNode();
    boolean isBucketNode = context.getBucketList() != null;
    switch (this.aggFuncType) {

      case OQLLexerTokenTypes.SUM:
        if (isPRQueryNode) {
          return this.distinctOnly ? new SumDistinctPRQueryNode() : new Sum();
        } else {
          return this.distinctOnly ? (isBucketNode ? new DistinctAggregator() : new SumDistinct())
              : new Sum();
        }

      case OQLLexerTokenTypes.MAX:
        return new MaxMin(true);

      case OQLLexerTokenTypes.MIN:
        return new MaxMin(false);

      case OQLLexerTokenTypes.AVG:
        if (isPRQueryNode) {
          return this.distinctOnly ? new AvgDistinctPRQueryNode() : new AvgPRQueryNode();
        } else {
          return this.distinctOnly ? (isBucketNode ? new DistinctAggregator() : new AvgDistinct())
              : (isBucketNode ? new AvgBucketNode() : new Avg());
        }

      case OQLLexerTokenTypes.COUNT:
        if (isPRQueryNode) {
          return this.distinctOnly ? new CountDistinctPRQueryNode() : new CountPRQueryNode();
        } else {
          return this.distinctOnly ? (isBucketNode ? new DistinctAggregator() : new CountDistinct())
              : new Count();
        }

      default:
        throw new UnsupportedOperationException("Aggregate function not implemented");

    }

  }

  private String getStringRep() {
    switch (this.aggFuncType) {

      case OQLLexerTokenTypes.SUM:
        return "sum";

      case OQLLexerTokenTypes.MAX:
        return "max";

      case OQLLexerTokenTypes.MIN:
        return "min";

      case OQLLexerTokenTypes.AVG:
        return "avg";
      case OQLLexerTokenTypes.COUNT:
        return "count";
      default:
        throw new UnsupportedOperationException("Aggregate function not implemented");

    }
  }

  public int getFunctionType() {
    return this.aggFuncType;
  }

  public CompiledValue getParameter() {
    return this.expr;
  }

  public ObjectType getObjectType() {
    switch (this.aggFuncType) {

      case OQLLexerTokenTypes.SUM:
      case OQLLexerTokenTypes.MAX:
      case OQLLexerTokenTypes.MIN:
      case OQLLexerTokenTypes.AVG:
        return new ObjectTypeImpl(Number.class);

      case OQLLexerTokenTypes.COUNT:
        return new ObjectTypeImpl(Integer.class);

      default:
        throw new UnsupportedOperationException("Aggregate function not implemented");

    }
  }

  @Override
  public void generateCanonicalizedExpression(StringBuilder clauseBuffer, ExecutionContext context)
      throws AmbiguousNameException, TypeMismatchException, NameResolutionException {
    clauseBuffer.insert(0, ')');
    if (this.expr != null) {
      this.expr.generateCanonicalizedExpression(clauseBuffer, context);
    } else {
      clauseBuffer.insert(0, '*');
    }
    if (this.distinctOnly) {
      clauseBuffer.insert(0, "distinct ");
    }
    clauseBuffer.insert(0, '(');
    clauseBuffer.insert(0, getStringRep());
  }
}