/* * 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.datasketches.hive.hll; import java.util.Arrays; import org.apache.datasketches.hll.HllSketch; import org.apache.datasketches.hll.TgtHllType; import org.apache.datasketches.memory.Memory; import org.apache.hadoop.hive.ql.exec.Description; import org.apache.hadoop.hive.ql.exec.UDFArgumentException; import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException; import org.apache.hadoop.hive.ql.metadata.HiveException; import org.apache.hadoop.hive.ql.parse.SemanticException; import org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDAFResolver; import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator; import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFParameterInfo; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils; import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory; import org.apache.hadoop.hive.serde2.objectinspector.StandardStructObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory; import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils; /** * Hive UDAF to compute union of HllSketch objects */ @Description( name = "unionSketch", value = "_FUNC_(sketch, lgK, type) - Compute the union of sketches of given size and seed", extended = "Example:\n" + "> SELECT UnionSketch(sketch) FROM src;\n" + "The return value is a binary blob that can be operated on by other sketch related functions." + " The lgK parameter controls the sketch size and rlative error expected from the sketch." + " It is optional an must be from 4 to 21. The default is 12, which is expected to yield errors" + " of roughly +-3% in the estimation of uniques with 95% confidence." + " The target type parameter is optional and must be 'HLL_4', 'HLL_6' or 'HLL_8'." + " The default is 'HLL_4'") public class UnionSketchUDAF extends AbstractGenericUDAFResolver { /** * Perform argument count check and argument type checking, returns an * appropriate evaluator to perform based on input type (which should always * be BINARY sketch). Also check lgK and target HLL type parameters if they are passed in. * * @see org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDAFResolver * #getEvaluator(org.apache.hadoop.hive.ql.udf.generic.GenericUDAFParameterInfo) * * @param info The parameter info to validate * @return The GenericUDAFEvaluator to use to compute the function. */ @Override public GenericUDAFEvaluator getEvaluator(final GenericUDAFParameterInfo info) throws SemanticException { final ObjectInspector[] inspectors = info.getParameterObjectInspectors(); if (inspectors.length < 1) { throw new UDFArgumentException("Please specify at least 1 argument"); } if (inspectors.length > 3) { throw new UDFArgumentTypeException(inspectors.length - 1, "Please specify no more than 3 arguments"); } ObjectInspectorValidator.validateGivenPrimitiveCategory(inspectors[0], 0, PrimitiveCategory.BINARY); // Validate second argument if present if (inspectors.length > 1) { ObjectInspectorValidator.validateIntegralParameter(inspectors[1], 1); if (!ObjectInspectorUtils.isConstantObjectInspector(inspectors[1])) { throw new UDFArgumentTypeException(1, "The second argument must be a constant"); } } // Validate third argument if present if (inspectors.length > 2) { ObjectInspectorValidator.validateGivenPrimitiveCategory(inspectors[2], 2, PrimitiveCategory.STRING); if (!ObjectInspectorUtils.isConstantObjectInspector(inspectors[2])) { throw new UDFArgumentTypeException(2, "The third argument must be a constant"); } } return new UnionSketchUDAFEvaluator(); } /** * Evaluator class, main logic of our UDAF. * */ public static class UnionSketchUDAFEvaluator extends SketchEvaluator { @SuppressWarnings("deprecation") @Override public AggregationBuffer getNewAggregationBuffer() throws HiveException { return new UnionState(); } /** * Receives the passed in argument object inspectors and returns the desired * return type's object inspector to inform hive of return type of UDAF. * * @param mode * Mode (i.e. PARTIAL 1, COMPLETE...) for determining input and output * object inspector type. * @param parameters * List of object inspectors for input arguments. * @return The object inspector type indicates the UDAF return type (i.e. * returned type of terminate(...)). */ @Override public ObjectInspector init(final Mode mode, final ObjectInspector[] parameters) throws HiveException { super.init(mode, parameters); if ((mode == Mode.PARTIAL1) || (mode == Mode.COMPLETE)) { inputInspector_ = (PrimitiveObjectInspector) parameters[0]; if (parameters.length > 1) { lgKInspector_ = (PrimitiveObjectInspector) parameters[1]; } if (parameters.length > 2) { hllTypeInspector_ = (PrimitiveObjectInspector) parameters[2]; } } else { // mode = partial2 || final intermediateInspector_ = (StandardStructObjectInspector) parameters[0]; } if ((mode == Mode.PARTIAL1) || (mode == Mode.PARTIAL2)) { // intermediate results need to include the lgK and the target HLL type return ObjectInspectorFactory.getStandardStructObjectInspector( Arrays.asList(LG_K_FIELD, HLL_TYPE_FIELD, SKETCH_FIELD), Arrays.asList( PrimitiveObjectInspectorFactory.getPrimitiveWritableObjectInspector(PrimitiveCategory.INT), PrimitiveObjectInspectorFactory.getPrimitiveWritableObjectInspector(PrimitiveCategory.STRING), PrimitiveObjectInspectorFactory.getPrimitiveWritableObjectInspector(PrimitiveCategory.BINARY) ) ); } // final results include just the sketch return PrimitiveObjectInspectorFactory.getPrimitiveWritableObjectInspector(PrimitiveCategory.BINARY); } /** * Add the incoming sketch into the internal state. * * @param buf * aggregation buffer storing intermediate results. * @param parameters * sketches in the form of Object passed in to be merged. */ @Override public void iterate(final @SuppressWarnings("deprecation") AggregationBuffer buf, final Object[] parameters) throws HiveException { if (parameters[0] == null) { return; } final UnionState state = (UnionState) buf; if (!state.isInitialized()) { initializeState(state, parameters); } final byte[] serializedSketch = (byte[]) inputInspector_.getPrimitiveJavaObject(parameters[0]); if (serializedSketch == null) { return; } state.update(HllSketch.wrap(Memory.wrap(serializedSketch))); } private void initializeState(final UnionState state, final Object[] parameters) { int lgK = DEFAULT_LG_K; if (lgKInspector_ != null) { lgK = PrimitiveObjectInspectorUtils.getInt(parameters[1], lgKInspector_); } TgtHllType type = DEFAULT_HLL_TYPE; if (hllTypeInspector_ != null) { type = TgtHllType.valueOf(PrimitiveObjectInspectorUtils.getString(parameters[2], hllTypeInspector_)); } state.init(lgK, type); } } }