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.om.pointables;
  
  import org.apache.asterix.om.pointables.base.DefaultOpenFieldType;
  import org.apache.asterix.om.pointables.base.IVisitablePointable;
  import org.apache.asterix.om.types.AOrderedListType;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.EnumDeserializer;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.om.types.TypeTagUtil;
  import org.apache.asterix.om.util.container.IObjectFactory;
  import org.apache.asterix.om.util.container.IObjectPool;
  import org.apache.asterix.om.util.container.ListObjectPool;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  
  /**
   * This class is the ONLY place to create IVisitablePointable object instances,
   * to enforce use of an object pool.
   */
  public class PointableAllocator {
  
      private IObjectPool<AFlatValuePointable, IAType> flatValueAllocator =
              new ListObjectPool<>(AFlatValuePointable.FACTORY);
      private IObjectPool<ARecordVisitablePointable, IAType> recordValueAllocator =
              new ListObjectPool<>(ARecordVisitablePointable.FACTORY);
      private IObjectPool<AListVisitablePointable, IAType> listValueAllocator =
              new ListObjectPool<>(AListVisitablePointable.FACTORY);
      private IObjectPool<AOrderedListType, IAType> orederedListTypeAllocator =
              new ListObjectPool<>(new IObjectFactory<AOrderedListType, IAType>() {
                  @Override
                  public AOrderedListType create(IAType type) {
                      return new AOrderedListType(type, type.getTypeName() + "OrderedList");
                  }
              });
      private IObjectPool<AOrderedListType, IAType> unorederedListTypeAllocator =
              new ListObjectPool<>(new IObjectFactory<AOrderedListType, IAType>() {
                  @Override
                  public AOrderedListType create(IAType type) {
                      return new AOrderedListType(type, type.getTypeName() + "UnorderedList");
                  }
              });
  
      public AFlatValuePointable allocateEmpty() {
          return flatValueAllocator.allocate(null);
      }
  
      /**
       * This method should ONLY be used for long lasting IVisitablePointable.
       *
       * @return
       *         a generic type IVisitablePointable.
       */
      public static IVisitablePointable allocateUnrestableEmpty() {
          return AFlatValuePointable.FACTORY.create(null);
      }
  
      /**
       * allocate closed part value pointable
       *
       * @param type
       * @return the pointable object
       */
      public IVisitablePointable allocateFieldValue(IAType type) {
          if (type == null)
              return flatValueAllocator.allocate(null);
          else if (type.getTypeTag().equals(ATypeTag.OBJECT))
              return recordValueAllocator.allocate(type);
          else if (type.getTypeTag().equals(ATypeTag.MULTISET) || type.getTypeTag().equals(ATypeTag.ARRAY))
              return listValueAllocator.allocate(type);
          else
              return flatValueAllocator.allocate(null);
      }
  
      /**
       * allocate open part value pointable
       *
       * @param typeTag
       * @return the pointable object
       */
      public IVisitablePointable allocateFieldValue(ATypeTag typeTag, byte[] b, int offset) throws HyracksDataException {
          if (typeTag == null)
              return flatValueAllocator.allocate(null);
          else if (typeTag.equals(ATypeTag.OBJECT))
              return recordValueAllocator.allocate(DefaultOpenFieldType.NESTED_OPEN_RECORD_TYPE);
          else if (typeTag.equals(ATypeTag.MULTISET)) {
              ATypeTag listItemType = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(b[offset]);
              if (listItemType == ATypeTag.ANY)
                  return listValueAllocator.allocate(DefaultOpenFieldType.NESTED_OPEN_AUNORDERED_LIST_TYPE);
              else {
                  if (listItemType.isDerivedType())
                      return allocateFieldValue(listItemType, b, offset + 1);
                  else
                      return listValueAllocator.allocate(
                              unorederedListTypeAllocator.allocate(TypeTagUtil.getBuiltinTypeByTag(listItemType)));
              }
          } else if (typeTag.equals(ATypeTag.ARRAY)) {
              ATypeTag listItemType = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(b[offset]);
              if (listItemType == ATypeTag.ANY)
                  return listValueAllocator.allocate(DefaultOpenFieldType.NESTED_OPEN_AORDERED_LIST_TYPE);
              else {
                  if (listItemType.isDerivedType())
                      return allocateFieldValue(listItemType, b, offset + 1);
                  else
                      return listValueAllocator.allocate(
                              orederedListTypeAllocator.allocate(TypeTagUtil.getBuiltinTypeByTag(listItemType)));
              }
          } else
              return flatValueAllocator.allocate(null);
      }
  
      public AListVisitablePointable allocateListValue(IAType type) {
          return listValueAllocator.allocate(type);
      }
  
      public ARecordVisitablePointable allocateRecordValue(IAType type) {
          return recordValueAllocator.allocate(type);
      }
  
      public void freeRecord(ARecordVisitablePointable instance) {
          recordValueAllocator.free(instance);
      }
  
      public void reset() {
          flatValueAllocator.reset();
          recordValueAllocator.reset();
          listValueAllocator.reset();
      }
  }
  