code: /*
   * Copyright 2012-2018 Chronicle Map Contributors
   *
   * Licensed 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 net.openhft.chronicle.hash.impl;
  
  import net.openhft.chronicle.core.OS;
  
  import static net.openhft.chronicle.assertions.AssertUtil.SKIP_ASSERTIONS;
  import static net.openhft.chronicle.map.internal.InternalAssertUtil.assertAddress;
  import static net.openhft.chronicle.map.internal.InternalAssertUtil.assertPosition;
  
  public final class IntCompactOffHeapLinearHashTable extends CompactOffHeapLinearHashTable {
  
      private static final long SCALE = 4L;
  
      /**
       * Must not store {@code h} in a field, to avoid memory leaks.
       *
       * @see net.openhft.chronicle.hash.impl.stage.hash.Chaining#initMap
       */
      IntCompactOffHeapLinearHashTable(VanillaChronicleHash h) {
          super(h);
      }
  
      @Override
      long indexToPos(long index) {
          return index * SCALE;
      }
  
      @Override
      public long step(long pos) {
          return (pos + SCALE) & capacityMask2;
      }
  
      @Override
      public long stepBack(long pos) {
          return (pos - SCALE) & capacityMask2;
      }
  
      @Override
      public long readEntry(final long address,
                            final long pos) {
          assert SKIP_ASSERTIONS || assertAddress(address);
          assert SKIP_ASSERTIONS || assertPosition(pos);
          return OS.memory().readInt(address + pos);
      }
  
      @Override
      public long readEntryVolatile(final long address,
                                    final long pos) {
          assert SKIP_ASSERTIONS || assertAddress(address);
          assert SKIP_ASSERTIONS || assertPosition(pos);
          return OS.memory().readVolatileInt(address + pos);
      }
  
      @Override
      public void writeEntryVolatile(final long address,
                                     final long pos,
                                     final long key,
                                     final long value) {
          assert SKIP_ASSERTIONS || assertAddress(address);
          assert SKIP_ASSERTIONS || assertPosition(pos);
          OS.memory().writeVolatileInt(address + pos, (int) entry(key, value));
      }
  
      @Override
      public void writeEntry(long address, long pos, long newEntry) {
          assert SKIP_ASSERTIONS || assertAddress(address);
          assert SKIP_ASSERTIONS || assertPosition(pos);
          OS.memory().writeInt(address + pos, (int) newEntry);
      }
  
      @Override
      public void clearEntry(long address, long pos) {
          assert SKIP_ASSERTIONS || assertAddress(address);
          assert SKIP_ASSERTIONS || assertPosition(pos);
          OS.memory().writeInt(address + pos, 0);
      }
  }