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Infinispan Embedded All-in-One module

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package org.infinispan.iteration.impl;

import org.infinispan.Cache;
import org.infinispan.commons.util.CloseableIterator;
import org.infinispan.container.entries.CacheEntry;

import java.util.NoSuchElementException;

/**
 * A CloseableIterator implementation that allows for a CloseableIterator that doesn't allow remove operations to
 * implement remove by delegating the call to the provided cache to remove the previously read value.
 *
 * @author wburns
 * @since 7.0
 */
public class RemovableEntryIterator implements CloseableIterator> {
   protected final CloseableIterator> realIterator;
   protected final Cache cache;

   protected CacheEntry previousValue;
   protected CacheEntry currentValue;

   public RemovableEntryIterator(CloseableIterator> realIterator,
                                            Cache cache, boolean initIterator) {
      this.realIterator = realIterator;
      this.cache = cache;
      if (initIterator) {
         currentValue = getNextFromIterator();
      }
   }

   protected CacheEntry getNextFromIterator() {
      if (realIterator.hasNext()) {
         return (CacheEntry) realIterator.next();
      } else {
         return null;
      }
   }

   @Override
   public boolean hasNext() {
      return currentValue != null;
   }

   @Override
   public CacheEntry next() {
      if (currentValue == null) {
         throw new NoSuchElementException();
      }
      previousValue = currentValue;
      // Set the current value to the next one if there is one
      currentValue = getNextFromIterator();
      return previousValue;
   }

   @Override
   public void remove() {
      if (previousValue == null) {
         throw new IllegalStateException();
      }
      cache.remove(previousValue.getKey());
      previousValue = null;
   }

   @Override
   public void close() {
      currentValue = null;
      previousValue = null;
      realIterator.close();
   }
}