| /* |
| * 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.druid.query.aggregation; |
| |
| import org.apache.druid.math.expr.Expr; |
| import org.apache.druid.math.expr.ExprEval; |
| |
| import javax.annotation.Nullable; |
| |
| public class ExpressionLambdaAggregator implements Aggregator |
| { |
| private final Expr lambda; |
| private final ExpressionLambdaAggregatorInputBindings bindings; |
| private final int maxSizeBytes; |
| private boolean hasValue; |
| |
| public ExpressionLambdaAggregator( |
| final Expr lambda, |
| final ExpressionLambdaAggregatorInputBindings bindings, |
| final boolean isNullUnlessAggregated, |
| final int maxSizeBytes |
| ) |
| { |
| this.lambda = lambda; |
| this.bindings = bindings; |
| this.maxSizeBytes = maxSizeBytes; |
| this.hasValue = !isNullUnlessAggregated; |
| } |
| |
| @Override |
| public void aggregate() |
| { |
| final ExprEval<?> eval = lambda.eval(bindings); |
| ExprEval.estimateAndCheckMaxBytes(eval, maxSizeBytes); |
| bindings.accumulate(eval); |
| hasValue = true; |
| } |
| |
| @Nullable |
| @Override |
| public Object get() |
| { |
| return hasValue ? bindings.getAccumulator().value() : null; |
| } |
| |
| @Override |
| public float getFloat() |
| { |
| return (float) bindings.getAccumulator().asDouble(); |
| } |
| |
| @Override |
| public long getLong() |
| { |
| return bindings.getAccumulator().asLong(); |
| } |
| |
| @Override |
| public double getDouble() |
| { |
| return bindings.getAccumulator().asDouble(); |
| } |
| |
| @Override |
| public boolean isNull() |
| { |
| return bindings.getAccumulator().isNumericNull(); |
| } |
| |
| @Override |
| public void close() |
| { |
| // nothing to close |
| } |
| } |