* handling text normalization, content extraction, and similar document hash encoding/decoding.
 * It also manages document processing requests and integrates with the crawler system.
 *
 */
public class DocumentHelper {
    private static final Logger logger = LogManager.getLogger(DocumentHelper.class);

    /** Prefix used for encoded similar document hashes */
    protected static final String SIMILAR_DOC_HASH_PREFIX = "$";

   * the discussion in the {@link #addListener} documentation. All its warnings about heavyweight
   * listeners are also applicable to heavyweight functions passed to this method.
   *
   * <p>This method is similar to {@link java.util.concurrent.CompletableFuture#exceptionally}. It
   * can also serve some of the use cases of {@link java.util.concurrent.CompletableFuture#handle}

...
BUILD SUCCESSFUL in 1m 30s
63 actionable tasks: 61 executed, 2 up-to-date

```

    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code future.}{@link Future#get() get()} uninterruptibly.
   *
   * <p>Similar methods:
   *
   * <ul>
   *   <li>To retrieve a result from a {@code Future} that is already done, use {@link
   *       Futures#getDone Futures.getDone}.

 * sum that is used for purposes such as collecting statistics, not for fine-grained synchronization
 * control. Under low update contention, the two classes have similar characteristics. But under
 * high contention, expected throughput of this class is significantly higher, at the expense of
 * higher space consumption.
 *

@GwtCompatible
abstract class CollectionFuture<V extends @Nullable Object, C extends @Nullable Object>
    extends AggregateFuture<V, C> {
  /*
   * We access this field racily but safely. For discussion of a similar situation, see the comments
   * on the fields of TimeoutFuture. This field is slightly different from the fields discussed
   * there: cancel() never reads this field, only writes to it. That makes the race here completely

/**
 * API action for admin duplicate host management.
 * Provides RESTful API endpoints for managing duplicate host settings in the Fess search engine.
 * Duplicate host settings help prevent indexing the same content from multiple similar URLs.
 *
 */
public class ApiAdminDuplicatehostAction extends FessApiAdminAction {

    private static final Logger logger = LogManager.getLogger(ApiAdminDuplicatehostAction.class);

     */
    @ValidateTypeFailure
    public Integer offset;

    /**
     * The page number for pagination.
     */
    @ValidateTypeFailure
    public Integer pn;

    /**
     * Similar document hash for finding related documents.
     */
    @Size(max = 1000)
    public String sdh;

    /**
     * Parameter to control tracking of total hits in search results.
     */
    @Size(max = 100)

  //   timeout is small we shouldn't park(). This needs to be traded off with the cpu overhead of
  //   spinning, so we use SPIN_THRESHOLD_NANOS which is what AbstractQueuedSynchronizer uses for
  //   similar purposes.
  // * We want to behave reasonably for timeouts of 0
  // * We are more responsive to completion than timeouts. This is because parkNanos depends on

  // final fields.
  //
  // For simplicity the rest of this description will discuss Futures.catching since it is the
  // simplest instance, though very similar descriptions apply to many other classes in this file.
  //
  // In the constructor of AbstractCatchingFuture, the delegate future is assigned to a field