EvictingQueueBuilder.java

//Dstl (c) Crown Copyright 2017
package uk.gov.dstl.baleen.core.logging.builders;

import java.util.List;

import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.Appender;
import ch.qos.logback.core.encoder.Encoder;
import ch.qos.logback.core.filter.Filter;

/**
 * Create an in memory holder and appender for log events, of type
 * {@link EvictingQueueAppender}.
 *
 * Note that this builder will return the same instance for each call to
 * createAppender
 *
 * 
 *
 */
public class EvictingQueueBuilder extends AbstractBaleenLoggerBuilder {

	private static final String NAME = "evicting";
	private final EvictingQueueAppender<ILoggingEvent> appender;

	/**
	 * New instances
	 *
	 * @param pattern
	 *            as per {@link AbstractBaleenLoggerBuilder}
	 * @param filters
	 *            as per {@link AbstractBaleenLoggerBuilder}
	 * @param maxSize
	 *            the maximum number of log events to store in memory.
	 */
	public EvictingQueueBuilder(String pattern, List<Filter<ILoggingEvent>> filters, int maxSize) {
		super(NAME, pattern, filters);
		this.appender = new EvictingQueueAppender<ILoggingEvent>(maxSize);
	}

	/**
	 * Get the appender which has been created.
	 *
	 * @return the appender
	 */
	public EvictingQueueAppender<ILoggingEvent> getAppender() {
		return appender;
	}

	@Override
	protected Appender<ILoggingEvent> createAppender(LoggerContext context, Encoder<ILoggingEvent> encoder) {
		return appender;
	}

}