content: /*
   * 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.asterix.runtime.aggregates.std;
  
  import java.io.DataOutput;
  import java.io.DataOutputStream;
  import java.io.IOException;
  
  import org.apache.asterix.dataflow.data.nontagged.serde.ADoubleSerializerDeserializer;
  import org.apache.asterix.dataflow.data.nontagged.serde.AFloatSerializerDeserializer;
  import org.apache.asterix.dataflow.data.nontagged.serde.AInt16SerializerDeserializer;
  import org.apache.asterix.dataflow.data.nontagged.serde.AInt32SerializerDeserializer;
  import org.apache.asterix.dataflow.data.nontagged.serde.AInt64SerializerDeserializer;
  import org.apache.asterix.dataflow.data.nontagged.serde.AInt8SerializerDeserializer;
  import org.apache.asterix.dataflow.data.nontagged.serde.ARecordSerializerDeserializer;
  import org.apache.asterix.formats.nontagged.SerializerDeserializerProvider;
  import org.apache.asterix.om.base.ADouble;
  import org.apache.asterix.om.base.AInt64;
  import org.apache.asterix.om.base.AMutableDouble;
  import org.apache.asterix.om.base.AMutableInt64;
  import org.apache.asterix.om.base.ANull;
  import org.apache.asterix.om.types.ARecordType;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.BuiltinType;
  import org.apache.asterix.om.types.EnumDeserializer;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.om.types.hierachy.ATypeHierarchy;
  import org.apache.asterix.runtime.aggregates.utils.SingleVarFunctionsUtil;
  import org.apache.asterix.runtime.evaluators.common.AccessibleByteArrayEval;
  import org.apache.asterix.runtime.evaluators.common.ClosedRecordConstructorEvalFactory.ClosedRecordConstructorEval;
  import org.apache.asterix.runtime.exceptions.IncompatibleTypeException;
  import org.apache.asterix.runtime.exceptions.UnsupportedItemTypeException;
  import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
  import org.apache.hyracks.api.context.IEvaluatorContext;
  import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.api.exceptions.SourceLocation;
  import org.apache.hyracks.data.std.api.IPointable;
  import org.apache.hyracks.data.std.primitive.VoidPointable;
  import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
  import org.apache.hyracks.data.std.util.ByteArrayAccessibleOutputStream;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  
  public abstract class AbstractSingleVarStatisticsAggregateFunction extends AbstractAggregateFunction {
  
      /*
      M1 and M2 are the 1st and 2nd central moment of a data sample
       */
      private static final int M1_FIELD_ID = 0;
      private static final int M2_FIELD_ID = 1;
      private static final int M3_FIELD_ID = 2;
      private static final int M4_FIELD_ID = 3;
      private static final int COUNT_FIELD_ID = 4;
  
      private final ARecordType recType;
  
      private ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
      private IPointable inputVal = new VoidPointable();
      private IScalarEvaluator eval;
      protected ATypeTag aggType;
      private SingleVarFunctionsUtil moments = new SingleVarFunctionsUtil();
      private AMutableDouble aDouble = new AMutableDouble(0);
      private AMutableInt64 aInt64 = new AMutableInt64(0);
  
      private IPointable resultBytes = new VoidPointable();
      private ByteArrayAccessibleOutputStream m1Bytes = new ByteArrayAccessibleOutputStream();
      private DataOutput m1BytesOutput = new DataOutputStream(m1Bytes);
      private ByteArrayAccessibleOutputStream m2Bytes = new ByteArrayAccessibleOutputStream();
      private DataOutput m2BytesOutput = new DataOutputStream(m2Bytes);
      private ByteArrayAccessibleOutputStream m3Bytes = new ByteArrayAccessibleOutputStream();
      private DataOutput m3BytesOutput = new DataOutputStream(m3Bytes);
      private ByteArrayAccessibleOutputStream m4Bytes = new ByteArrayAccessibleOutputStream();
      private DataOutput m4BytesOutput = new DataOutputStream(m4Bytes);
      private ByteArrayAccessibleOutputStream countBytes = new ByteArrayAccessibleOutputStream();
      private DataOutput countBytesOutput = new DataOutputStream(countBytes);
      private IScalarEvaluator evalM1 = new AccessibleByteArrayEval(m1Bytes);
      private IScalarEvaluator evalM2 = new AccessibleByteArrayEval(m2Bytes);
      private IScalarEvaluator evalM3 = new AccessibleByteArrayEval(m3Bytes);
      private IScalarEvaluator evalM4 = new AccessibleByteArrayEval(m4Bytes);
      private IScalarEvaluator evalCount = new AccessibleByteArrayEval(countBytes);
      private ClosedRecordConstructorEval recordEval;
  
      @SuppressWarnings("unchecked")
      private ISerializerDeserializer<ADouble> doubleSerde =
              SerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.ADOUBLE);
      @SuppressWarnings("unchecked")
      private ISerializerDeserializer<AInt64> longSerde =
              SerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.AINT64);
      @SuppressWarnings("unchecked")
      private ISerializerDeserializer<ANull> nullSerde =
              SerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.ANULL);
  
      public AbstractSingleVarStatisticsAggregateFunction(IScalarEvaluatorFactory[] args, IEvaluatorContext context,
              SourceLocation sourceLoc) throws HyracksDataException {
          super(sourceLoc);
          eval = args[0].createScalarEvaluator(context);
          recType =
                  new ARecordType(null,
                          new String[] { "m1", "m2", "m3", "m4", "count" }, new IAType[] { BuiltinType.ADOUBLE,
                                  BuiltinType.ADOUBLE, BuiltinType.ADOUBLE, BuiltinType.ADOUBLE, BuiltinType.AINT64 },
                          false);
          recordEval = new ClosedRecordConstructorEval(recType,
                  new IScalarEvaluator[] { evalM1, evalM2, evalM3, evalM4, evalCount });
      }
  
      @Override
      public void init() throws HyracksDataException {
          aggType = ATypeTag.SYSTEM_NULL;
          moments.set(0, 0, 0, 0, 0, getM3Flag(), getM4Flag());
      }
  
      @Override
      public abstract void step(IFrameTupleReference tuple) throws HyracksDataException;
  
      @Override
      public abstract void finish(IPointable result) throws HyracksDataException;
  
      @Override
      public abstract void finishPartial(IPointable result) throws HyracksDataException;
  
      protected abstract FunctionIdentifier getFunctionIdentifier();
  
      protected abstract void processNull();
  
      protected abstract boolean getM3Flag();
  
      protected abstract boolean getM4Flag();
  
      protected void processDataValues(IFrameTupleReference tuple) throws HyracksDataException {
          if (skipStep()) {
              return;
          }
          eval.evaluate(tuple, inputVal);
          byte[] data = inputVal.getByteArray();
          int offset = inputVal.getStartOffset();
  
          ATypeTag typeTag = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(data[offset]);
          if (typeTag == ATypeTag.MISSING || typeTag == ATypeTag.NULL) {
              processNull();
              return;
          } else if (aggType == ATypeTag.SYSTEM_NULL) {
              aggType = typeTag;
          } else if (typeTag != ATypeTag.SYSTEM_NULL && !ATypeHierarchy.isCompatible(typeTag, aggType)) {
              if (typeTag.ordinal() > aggType.ordinal()) {
                  throw new IncompatibleTypeException(sourceLoc, getFunctionIdentifier(), data[offset],
                          aggType.serialize());
              } else {
                  throw new IncompatibleTypeException(sourceLoc, getFunctionIdentifier(), aggType.serialize(),
                          data[offset]);
              }
          } else if (ATypeHierarchy.canPromote(aggType, typeTag)) {
              aggType = typeTag;
          }
          double val;
          switch (typeTag) {
              case TINYINT:
                  val = AInt8SerializerDeserializer.getByte(data, offset + 1);
                  moments.push(val);
                  break;
              case SMALLINT:
                  val = AInt16SerializerDeserializer.getShort(data, offset + 1);
                  moments.push(val);
                  break;
              case INTEGER:
                  val = AInt32SerializerDeserializer.getInt(data, offset + 1);
                  moments.push(val);
                  break;
              case BIGINT:
                  val = AInt64SerializerDeserializer.getLong(data, offset + 1);
                  moments.push(val);
                  break;
              case FLOAT:
                  val = AFloatSerializerDeserializer.getFloat(data, offset + 1);
                  moments.push(val);
                  break;
              case DOUBLE:
                  val = ADoubleSerializerDeserializer.getDouble(data, offset + 1);
                  moments.push(val);
                  break;
              default:
                  throw new UnsupportedItemTypeException(sourceLoc, getFunctionIdentifier(), data[offset]);
          }
      }
  
      protected void finishPartialResults(IPointable result) throws HyracksDataException {
          resultStorage.reset();
          try {
              // Double check that count 0 is accounted
              if (aggType == ATypeTag.SYSTEM_NULL) {
                  resultStorage.getDataOutput().writeByte(ATypeTag.SERIALIZED_SYSTEM_NULL_TYPE_TAG);
                  result.set(resultStorage);
              } else if (aggType == ATypeTag.NULL) {
                  resultStorage.getDataOutput().writeByte(ATypeTag.SERIALIZED_NULL_TYPE_TAG);
                  result.set(resultStorage);
              } else {
                  m1Bytes.reset();
                  aDouble.setValue(moments.getM1());
                  doubleSerde.serialize(aDouble, m1BytesOutput);
                  m2Bytes.reset();
                  aDouble.setValue(moments.getM2());
                  doubleSerde.serialize(aDouble, m2BytesOutput);
                  m3Bytes.reset();
                  aDouble.setValue(moments.getM3());
                  doubleSerde.serialize(aDouble, m3BytesOutput);
                  m4Bytes.reset();
                  aDouble.setValue(moments.getM4());
                  doubleSerde.serialize(aDouble, m4BytesOutput);
                  countBytes.reset();
                  aInt64.setValue(moments.getCount());
                  longSerde.serialize(aInt64, countBytesOutput);
                  recordEval.evaluate(null, resultBytes);
                  result.set(resultBytes);
              }
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      protected void processPartialResults(IFrameTupleReference tuple) throws HyracksDataException {
          if (skipStep()) {
              return;
          }
          eval.evaluate(tuple, inputVal);
          byte[] serBytes = inputVal.getByteArray();
          int offset = inputVal.getStartOffset();
          ATypeTag typeTag = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(serBytes[offset]);
          switch (typeTag) {
              case NULL:
                  processNull();
                  break;
              case SYSTEM_NULL:
                  // Ignore and return.
                  break;
              case OBJECT:
                  // Expected.
                  aggType = ATypeTag.DOUBLE;
                  int nullBitmapSize = 0;
                  int offset1 = ARecordSerializerDeserializer.getFieldOffsetById(serBytes, offset, M1_FIELD_ID,
                          nullBitmapSize, false);
                  int offset2 = ARecordSerializerDeserializer.getFieldOffsetById(serBytes, offset, M2_FIELD_ID,
                          nullBitmapSize, false);
                  int offset3 = ARecordSerializerDeserializer.getFieldOffsetById(serBytes, offset, M3_FIELD_ID,
                          nullBitmapSize, false);
                  int offset4 = ARecordSerializerDeserializer.getFieldOffsetById(serBytes, offset, M4_FIELD_ID,
                          nullBitmapSize, false);
                  int offset5 = ARecordSerializerDeserializer.getFieldOffsetById(serBytes, offset, COUNT_FIELD_ID,
                          nullBitmapSize, false);
                  double temp_m1 = ADoubleSerializerDeserializer.getDouble(serBytes, offset1);
                  double temp_m2 = ADoubleSerializerDeserializer.getDouble(serBytes, offset2);
                  double temp_m3 = ADoubleSerializerDeserializer.getDouble(serBytes, offset3);
                  double temp_m4 = ADoubleSerializerDeserializer.getDouble(serBytes, offset4);
                  long temp_count = AInt64SerializerDeserializer.getLong(serBytes, offset5);
                  moments.combine(temp_m1, temp_m2, temp_m3, temp_m4, temp_count);
                  break;
              default:
                  throw new UnsupportedItemTypeException(sourceLoc, "intermediate/global-single-var-statistics",
                          serBytes[offset]);
          }
      }
  
      protected void finishStddevFinalResults(IPointable result, int delta) throws HyracksDataException {
          resultStorage.reset();
          try {
              long count = moments.getCount();
              if (count <= delta || aggType == ATypeTag.NULL) {
                  nullSerde.serialize(ANull.NULL, resultStorage.getDataOutput());
              } else {
                  aDouble.setValue(Math.sqrt(moments.getM2() / (count - delta)));
                  doubleSerde.serialize(aDouble, resultStorage.getDataOutput());
              }
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
          result.set(resultStorage);
      }
  
      protected void finishVarFinalResults(IPointable result, int delta) throws HyracksDataException {
          resultStorage.reset();
          try {
              long count = moments.getCount();
              if (count <= delta || aggType == ATypeTag.NULL) {
                  nullSerde.serialize(ANull.NULL, resultStorage.getDataOutput());
              } else {
                  aDouble.setValue(moments.getM2() / (count - delta));
                  doubleSerde.serialize(aDouble, resultStorage.getDataOutput());
              }
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
          result.set(resultStorage);
      }
  
      protected void finishSkewFinalResults(IPointable result) throws HyracksDataException {
          resultStorage.reset();
          try {
              long count = moments.getCount();
              double m2 = moments.getM2();
              if (count <= 2 || aggType == ATypeTag.NULL || (m2 < Double.MIN_VALUE && m2 > -Double.MIN_VALUE)) {
                  nullSerde.serialize(ANull.NULL, resultStorage.getDataOutput());
              } else {
                  aDouble.setValue(Math.sqrt(count) * moments.getM3() / Math.pow(m2, 1.5));
                  doubleSerde.serialize(aDouble, resultStorage.getDataOutput());
              }
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
          result.set(resultStorage);
      }
  
      protected void finishKurtFinalResults(IPointable result) throws HyracksDataException {
          resultStorage.reset();
          try {
              long count = moments.getCount();
              double m2 = moments.getM2();
              if (count <= 2 || aggType == ATypeTag.NULL || (m2 < Double.MIN_VALUE && m2 > -Double.MIN_VALUE)) {
                  nullSerde.serialize(ANull.NULL, resultStorage.getDataOutput());
              } else {
                  aDouble.setValue(moments.getM4() * count / (m2 * m2) - 3);
                  doubleSerde.serialize(aDouble, resultStorage.getDataOutput());
              }
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
          result.set(resultStorage);
      }
  
      protected boolean skipStep() {
          return false;
      }
  
  }
  