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.evaluators.functions.records;
  
  import java.io.DataOutput;
  import java.io.IOException;
  import java.util.ArrayDeque;
  import java.util.ArrayList;
  import java.util.Deque;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.asterix.builders.RecordBuilder;
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.asterix.om.pointables.AListVisitablePointable;
  import org.apache.asterix.om.pointables.ARecordVisitablePointable;
  import org.apache.asterix.om.pointables.PointableAllocator;
  import org.apache.asterix.om.pointables.base.DefaultOpenFieldType;
  import org.apache.asterix.om.pointables.base.IVisitablePointable;
  import org.apache.asterix.om.typecomputer.impl.TypeComputeUtils;
  import org.apache.asterix.om.types.AOrderedListType;
  import org.apache.asterix.om.types.ARecordType;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.runtime.RuntimeRecordTypeInfo;
  import org.apache.asterix.runtime.evaluators.functions.PointableHelper;
  import org.apache.asterix.runtime.exceptions.TypeMismatchException;
  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.IBinaryComparator;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.api.exceptions.SourceLocation;
  import org.apache.hyracks.data.std.accessors.UTF8StringBinaryComparatorFactory;
  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.dataflow.common.data.accessors.IFrameTupleReference;
  
  class RecordRemoveFieldsEvalFactory implements IScalarEvaluatorFactory {
      private static final long serialVersionUID = 1L;
      private IScalarEvaluatorFactory inputRecordEvalFactory;
      private IScalarEvaluatorFactory removeFieldPathsFactory;
      private ARecordType requiredRecType;
      private ARecordType inputRecType;
      private AOrderedListType inputListType;
      private final SourceLocation sourceLoc;
  
      public RecordRemoveFieldsEvalFactory(IScalarEvaluatorFactory inputRecordEvalFactory,
              IScalarEvaluatorFactory removeFieldPathsFactory, ARecordType requiredRecType, ARecordType inputRecType,
              AOrderedListType inputListType, SourceLocation sourceLoc) {
          this.inputRecordEvalFactory = inputRecordEvalFactory;
          this.removeFieldPathsFactory = removeFieldPathsFactory;
          this.requiredRecType = requiredRecType;
          this.inputRecType = inputRecType;
          this.inputListType = inputListType;
          this.sourceLoc = sourceLoc;
      }
  
      @Override
      public IScalarEvaluator createScalarEvaluator(final IEvaluatorContext ctx) throws HyracksDataException {
  
          final PointableAllocator pa = new PointableAllocator();
          final IVisitablePointable vp0 = pa.allocateRecordValue(inputRecType);
          final IVisitablePointable vp1 = pa.allocateListValue(inputListType);
          final IPointable inputArg0 = new VoidPointable();
          final IPointable inputArg1 = new VoidPointable();
          final IScalarEvaluator eval0 = inputRecordEvalFactory.createScalarEvaluator(ctx);
          final IScalarEvaluator eval1 = removeFieldPathsFactory.createScalarEvaluator(ctx);
          final IBinaryComparator stringBinaryComparator =
                  UTF8StringBinaryComparatorFactory.INSTANCE.createBinaryComparator();
  
          return new IScalarEvaluator() {
              private final RuntimeRecordTypeInfo runtimeRecordTypeInfo = new RuntimeRecordTypeInfo();
  
              private final List<RecordBuilder> rbStack = new ArrayList<>();
              private final ArrayBackedValueStorage tabvs = new ArrayBackedValueStorage();
              private final Deque<IVisitablePointable> recordPath = new ArrayDeque<>();
  
              private ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
              private DataOutput out = resultStorage.getDataOutput();
  
              @Override
              public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
                  resultStorage.reset();
                  eval0.evaluate(tuple, inputArg0);
                  eval1.evaluate(tuple, inputArg1);
  
                  if (PointableHelper.checkAndSetMissingOrNull(result, inputArg0, inputArg1)) {
                      return;
                  }
  
                  byte inputTypeTag0 = inputArg0.getByteArray()[inputArg0.getStartOffset()];
                  if (inputTypeTag0 != ATypeTag.SERIALIZED_RECORD_TYPE_TAG) {
                      throw new TypeMismatchException(sourceLoc, BuiltinFunctions.REMOVE_FIELDS, 0, inputTypeTag0,
                              ATypeTag.SERIALIZED_INT32_TYPE_TAG);
                  }
  
                  byte inputTypeTag1 = inputArg1.getByteArray()[inputArg1.getStartOffset()];
                  if (inputTypeTag1 != ATypeTag.SERIALIZED_ORDEREDLIST_TYPE_TAG) {
                      throw new TypeMismatchException(sourceLoc, BuiltinFunctions.REMOVE_FIELDS, 1, inputTypeTag1,
                              ATypeTag.SERIALIZED_ORDEREDLIST_TYPE_TAG);
                  }
  
                  vp0.set(inputArg0);
                  vp1.set(inputArg1);
  
                  ARecordVisitablePointable recordPointable = (ARecordVisitablePointable) vp0;
                  AListVisitablePointable listPointable = (AListVisitablePointable) vp1;
  
                  try {
                      recordPath.clear();
                      rbStack.clear();
                      processRecord(requiredRecType, recordPointable, listPointable, 0);
                      rbStack.get(0).write(out, true);
                  } catch (IOException e) {
                      throw HyracksDataException.create(e);
                  }
                  result.set(resultStorage);
              }
  
              private void processRecord(ARecordType requiredType, ARecordVisitablePointable srp,
                      AListVisitablePointable inputList, int nestedLevel) throws IOException {
                  if (rbStack.size() < (nestedLevel + 1)) {
                      rbStack.add(new RecordBuilder());
                  }
  
                  rbStack.get(nestedLevel).reset(requiredType);
                  rbStack.get(nestedLevel).init();
  
                  List<IVisitablePointable> fieldNames = srp.getFieldNames();
                  List<IVisitablePointable> fieldValues = srp.getFieldValues();
  
                  for (int i = 0; i < fieldNames.size(); i++) {
                      IVisitablePointable subRecFieldName = fieldNames.get(i);
                      recordPath.push(subRecFieldName);
                      if (isValidPath(inputList)) {
                          if (requiredType != null && requiredType.getTypeTag() != ATypeTag.ANY) {
                              addKeptFieldToSubRecord(requiredType, subRecFieldName, fieldValues.get(i),
                                      PointableHelper.getTypeTag(fieldValues.get(i)), inputList, nestedLevel);
                          } else {
                              addKeptFieldToSubRecord(DefaultOpenFieldType.NESTED_OPEN_RECORD_TYPE, subRecFieldName,
                                      fieldValues.get(i), PointableHelper.getTypeTag(fieldValues.get(i)), inputList,
                                      nestedLevel);
                          }
                      }
                      recordPath.pop();
                  }
              }
  
              private void addKeptFieldToSubRecord(ARecordType requiredType, IVisitablePointable fieldNamePointable,
                      IVisitablePointable fieldValuePointable, ATypeTag fieldTypePointable,
                      AListVisitablePointable inputList, int nestedLevel) throws IOException {
  
                  runtimeRecordTypeInfo.reset(requiredType);
                  int pos = runtimeRecordTypeInfo.getFieldIndex(fieldNamePointable.getByteArray(),
                          fieldNamePointable.getStartOffset() + 1, fieldNamePointable.getLength() - 1);
                  if (pos >= 0) { // Closed field
                      if (ATypeTag.OBJECT == fieldTypePointable
                              && PointableHelper.sameType(ATypeTag.OBJECT, fieldValuePointable)) {
                          processRecord((ARecordType) TypeComputeUtils.getActualType(requiredType.getFieldTypes()[pos]),
                                  (ARecordVisitablePointable) fieldValuePointable, inputList, nestedLevel + 1);
                          tabvs.reset();
                          rbStack.get(nestedLevel + 1).write(tabvs.getDataOutput(), true);
                          rbStack.get(nestedLevel).addField(pos, tabvs);
                      } else {
                          rbStack.get(nestedLevel).addField(pos, fieldValuePointable);
                      }
                  } else { // Open field
                      if (ATypeTag.OBJECT == fieldTypePointable) {
                          processRecord(null, (ARecordVisitablePointable) fieldValuePointable, inputList,
                                  nestedLevel + 1);
                          tabvs.reset();
                          rbStack.get(nestedLevel + 1).write(tabvs.getDataOutput(), true);
                          rbStack.get(nestedLevel).addField(fieldNamePointable, tabvs);
                      } else {
                          rbStack.get(nestedLevel).addField(fieldNamePointable, fieldValuePointable);
                      }
                  }
              }
  
              private boolean isValidPath(AListVisitablePointable inputList) throws HyracksDataException {
                  List<IVisitablePointable> items = inputList.getItems();
                  int pathLen = recordPath.size();
                  for (int i = 0; i < items.size(); i++) {
                      IVisitablePointable item = items.get(i);
                      if (PointableHelper.sameType(ATypeTag.ARRAY, item)) {
                          List<IVisitablePointable> inputPathItems = ((AListVisitablePointable) item).getItems();
  
                          if (pathLen == inputPathItems.size()) {
                              boolean match = true;
                              Iterator<IVisitablePointable> fpi = recordPath.iterator();
                              for (int j = inputPathItems.size() - 1; j >= 0; j--) {
                                  match &= PointableHelper.isEqual(inputPathItems.get(j), fpi.next(),
                                          stringBinaryComparator);
                                  if (!match) {
                                      break;
                                  }
                              }
                              if (match) {
                                  return false; // Not a valid path for the output record
                              }
                          }
                      } else {
                          if (PointableHelper.isEqual(recordPath.getFirst(), item, stringBinaryComparator)) {
                              return false;
                          }
                      }
                  }
                  return true;
              }
          };
      }
  }
  