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.stage.query;
  
  import net.openhft.chronicle.bytes.Bytes;
  import net.openhft.chronicle.hash.Data;
  import net.openhft.chronicle.hash.impl.stage.entry.HashEntryStages;
  import net.openhft.chronicle.hash.impl.stage.entry.HashLookupSearch;
  import net.openhft.chronicle.hash.impl.stage.entry.SegmentStages;
  import net.openhft.chronicle.map.impl.VanillaChronicleMapHolder;
  import net.openhft.sg.Stage;
  import net.openhft.sg.StageRef;
  import net.openhft.sg.Staged;
  
  import static net.openhft.chronicle.hash.impl.stage.query.KeySearch.SearchState.ABSENT;
  import static net.openhft.chronicle.hash.impl.stage.query.KeySearch.SearchState.PRESENT;
  
  @Staged
  public abstract class KeySearch<K> {
  
      @StageRef
      public SegmentStages s;
      @StageRef
      public HashLookupSearch hashLookupSearch;
      @StageRef
      public HashEntryStages<K> entry;
      public Data<K> inputKey = null;
      @Stage("KeySearch")
      protected SearchState searchState = null;
      @StageRef
      VanillaChronicleMapHolder<?, ?, ?> mh;
  
      public abstract boolean inputKeyInit();
  
      public void initInputKey(Data<K> inputKey) {
          this.inputKey = inputKey;
      }
  
      public abstract boolean keySearchInit();
  
      @Stage("KeySearch")
      public void setSearchState(SearchState newSearchState) {
          this.searchState = newSearchState;
      }
  
      public void initKeySearch() {
          for (long pos; (pos = hashLookupSearch.nextPos()) >= 0L; ) {
              // otherwise we are inside iteration relocation.
              // During iteration, key search occurs when doReplaceValue() exhausts space in
              // the current segment, and insertion into the tiered segment requires to locate
              // an empty slot in the hashLookup.
              if (inputKeyInit()) {
                  long keySizeOffset = s.entrySpaceOffset + pos * mh.m().chunkSize;
                  Bytes segmentBytes = s.segmentBytesForRead();
                  segmentBytes.readPosition(keySizeOffset);
                  long keySize = mh.h().keySizeMarshaller.readSize(segmentBytes);
                  long keyOffset = segmentBytes.readPosition();
                  if (!keyEquals(keySize, keyOffset))
                      continue;
                  hashLookupSearch.found();
                  entry.readFoundEntry(pos, keySizeOffset, keySize, keyOffset);
                  searchState = PRESENT;
                  return;
              }
          }
          searchState = SearchState.ABSENT;
      }
  
      boolean keyEquals(long keySize, long keyOffset) {
          return inputKey.size() == keySize && inputKey.equivalent(s.segmentBS, keyOffset);
      }
  
      public boolean searchStatePresent() {
          return searchState == PRESENT;
      }
  
      public boolean searchStateAbsent() {
          return searchState == ABSENT;
      }
  
      public enum SearchState {
          PRESENT,
          ABSENT
      }
  }
  