} catch (final Exception e) {
            maxBufferSize = 1000;
        }
        queue.offer(event);
        if (size.incrementAndGet() > maxBufferSize) {
            if (queue.poll() != null) {
                size.decrementAndGet();
            }
        }
    }

    /**
     * Drains all events from the buffer and returns them as a list.

            }
        }
        return true;
    }

    /**
     * Stores child URLs from the given set into the crawling queue for future processing.
     * This method filters out blank URLs and increments the depth for child URLs.
     *
     * @param urlQueue the parent URL queue item
     * @param childUrlSet the set of child URLs to be queued for crawling
     */

            errorsField.setAccessible(true);
            Queue<String> errors = (Queue<String>) errorsField.get(null);
            errors.clear();
        } catch (Exception e) {
            // Ignore if field doesn't exist
        }

        // Add some errors to the queue
        Crawler.addError("Error 1");
        Crawler.addError("Error 2");

import org.opensearch.index.query.functionscore.RandomScoreFunctionBuilder;
import org.opensearch.search.sort.SortBuilders;
import org.opensearch.search.sort.SortOrder;

/**
 * Fess-specific URL queue service that extends OpenSearch URL queue functionality.
 * This service provides customized URL fetching strategies including sequential and random ordering
 * based on crawling configuration parameters.
 */

    /**
     * Gets the delay time in milliseconds when there are no URLs in the queue.
     *
     * @return the delay time in milliseconds when no URLs are available
     */
    public long getDelayMillisAtNoUrlInQueue() {
        return delayMillisAtNoUrlInQueue;
    }

    /**
     * Sets the delay time in milliseconds when there are no URLs in the queue.
     *

    /**
     * Maximum size of the thumbnail generation task queue.
     */
    protected int thumbnailTaskQueueSize = 10000;

    /**
     * Number of tasks to process in bulk operations.
     */
    protected int thumbnailTaskBulkSize = 100;

    /**
     * Timeout in milliseconds for thumbnail task queue operations.
     */
    protected long thumbnailTaskQueueTimeout = 10 * 1000L;

    /** Service for managing crawled document data */
    @Resource
    protected DataService<OpenSearchAccessResult> dataService;

    /** Service for managing URL crawling queue */
    @Resource
    protected UrlQueueService<OpenSearchUrlQueue> urlQueueService;

    /** Service for URL filtering operations */
    @Resource
    protected UrlFilterService urlFilterService;

	"http://dbflute.org/meta/lastadi10.dtd">
<components namespace="fessCrawler">
	<component name="crawlerConfig" class="org.codelibs.fess.crawler.util.FessCrawlerConfig">
		<property name="queueIndex">"fess_crawler.queue"</property>
		<property name="queueShards">5</property>
		<property name="queueReplicas">1</property>
		<property name="dataIndex">"fess_crawler.data"</property>
		<property name="dataShards">5</property>

        docMap.put("_id", "docid1");

        boolean result = thumbnailManager.offer(docMap);
        assertFalse(result);
    }

    // Test offer with full queue
    @Test
    public void test_offer_fullQueue() {
        thumbnailManager.setThumbnailTaskQueueSize(1);
        thumbnailManager.init();

        TestThumbnailGenerator generator = new TestThumbnailGenerator();

            throw e;
        }
        saveInfo(messages -> messages.addSuccessStartedDataUpdate(GLOBAL));
        return redirect(getClass());
    }

    /**
     * Clears all crawler indices including queue, data, and filter indices.
     *
     * @param form the action form (validated but not used for configuration)
     * @return HTML response redirecting to the maintenance page
     */
    @Execute