| /* |
| * 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 org.apache.druid.math.expr.ExprType; |
| |
| import javax.annotation.Nullable; |
| import java.nio.ByteBuffer; |
| |
| public class ExpressionLambdaBufferAggregator implements BufferAggregator |
| { |
| private static final short NOT_AGGREGATED_BIT = 1 << 7; |
| private static final short IS_AGGREGATED_MASK = 0x3F; |
| private final Expr lambda; |
| private final ExprEval<?> initialValue; |
| private final ExpressionLambdaAggregatorInputBindings bindings; |
| private final int maxSizeBytes; |
| private final boolean isNullUnlessAggregated; |
| |
| public ExpressionLambdaBufferAggregator( |
| Expr lambda, |
| ExprEval<?> initialValue, |
| ExpressionLambdaAggregatorInputBindings bindings, |
| boolean isNullUnlessAggregated, |
| int maxSizeBytes |
| ) |
| { |
| this.lambda = lambda; |
| this.initialValue = initialValue; |
| this.bindings = bindings; |
| this.isNullUnlessAggregated = isNullUnlessAggregated; |
| this.maxSizeBytes = maxSizeBytes; |
| } |
| |
| @Override |
| public void init(ByteBuffer buf, int position) |
| { |
| ExprEval.serialize(buf, position, initialValue, maxSizeBytes); |
| // set a bit to indicate we haven't aggregated on top of expression type (not going to lie this could be nicer) |
| if (isNullUnlessAggregated) { |
| buf.put(position, (byte) (buf.get(position) | NOT_AGGREGATED_BIT)); |
| } |
| } |
| |
| @Override |
| public void aggregate(ByteBuffer buf, int position) |
| { |
| ExprEval<?> acc = ExprEval.deserialize(buf, position + 1, getType(buf, position)); |
| bindings.setAccumulator(acc); |
| ExprEval<?> newAcc = lambda.eval(bindings); |
| ExprEval.serialize(buf, position, newAcc, maxSizeBytes); |
| // scrub not aggregated bit |
| buf.put(position, (byte) (buf.get(position) & IS_AGGREGATED_MASK)); |
| } |
| |
| @Nullable |
| @Override |
| public Object get(ByteBuffer buf, int position) |
| { |
| if (isNullUnlessAggregated && (buf.get(position) & NOT_AGGREGATED_BIT) != 0) { |
| return null; |
| } |
| return ExprEval.deserialize(buf, position + 1, getType(buf, position)).value(); |
| } |
| |
| @Override |
| public float getFloat(ByteBuffer buf, int position) |
| { |
| return (float) ExprEval.deserialize(buf, position + 1, getType(buf, position)).asDouble(); |
| } |
| |
| @Override |
| public double getDouble(ByteBuffer buf, int position) |
| { |
| return ExprEval.deserialize(buf, position + 1, getType(buf, position)).asDouble(); |
| } |
| |
| @Override |
| public long getLong(ByteBuffer buf, int position) |
| { |
| return ExprEval.deserialize(buf, position + 1, getType(buf, position)).asLong(); |
| } |
| |
| @Override |
| public void close() |
| { |
| // nothing to close |
| } |
| |
| private static ExprType getType(ByteBuffer buf, int position) |
| { |
| return ExprType.fromByte((byte) (buf.get(position) & IS_AGGREGATED_MASK)); |
| } |
| } |