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.carbondata.core.datastore.page;
  
  import org.apache.carbondata.core.datastore.page.encoding.ColumnPageEncoderMeta;
  import org.apache.carbondata.core.memory.CarbonUnsafe;
  import org.apache.carbondata.core.memory.MemoryBlock;
  import org.apache.carbondata.core.memory.UnsafeMemoryManager;
  
  public abstract class UnsafeVarLengthColumnPageBase extends VarLengthColumnPageBase {
  
    // memory allocated by Unsafe
    protected MemoryBlock memoryBlock;
  
    // base address of memoryBlock
    protected Object baseAddress;
  
    // base offset of memoryBlock
    protected long baseOffset;
  
    // size of the allocated memory, in bytes
    protected int capacity;
  
    UnsafeVarLengthColumnPageBase(ColumnPageEncoderMeta columnPageEncoderMeta, int pageSize) {
      super(columnPageEncoderMeta, pageSize);
    }
  
    /**
     * reallocate memory if capacity length than current size + request size
     */
    protected void ensureMemory(int requestSize) {
      if (totalLength + requestSize > capacity) {
        int newSize = Math.max(2 * capacity, totalLength + requestSize);
        MemoryBlock newBlock = UnsafeMemoryManager.allocateMemoryWithRetry(taskId, newSize);
        CarbonUnsafe.getUnsafe().copyMemory(baseAddress, baseOffset,
            newBlock.getBaseObject(), newBlock.getBaseOffset(), capacity);
        UnsafeMemoryManager.INSTANCE.freeMemory(taskId, memoryBlock);
        memoryBlock = newBlock;
        baseAddress = newBlock.getBaseObject();
        baseOffset = newBlock.getBaseOffset();
        capacity = newSize;
      }
    }
  
  }
  