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 * Licensed to the Apache Software Foundation (ASF) under one
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 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
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package org.apache.http.conn;

import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpResponse;
import org.apache.http.protocol.HttpContext;

/**
 * Interface for deciding how long a connection can remain
 * idle before being reused.
 *
 * @author <a href="mailto:sberlin at gmail.com">Sam Berlin</a>
 *
 *
 * @version $Revision: $
 * 
 * @since 4.0
 */
public interface ConnectionKeepAliveStrategy {
    
    /**
     * Returns the duration of time which this connection can be safely kept
     * idle. If the connection is left idle for longer than this period of time,
     * it MUST not reused. A value of 0 or less may be returned to indicate that
     * there is no suitable suggestion.
     * 
     * When coupled with a {@link ConnectionReuseStrategy}, if
     * {@link ConnectionReuseStrategy#keepAlive(HttpResponse, HttpContext)
     * returns true, this allows you to control how long the reuse will last. If
     * keepAlive returns false, this should have no meaningful impact
     * 
     * @param response
     *            The last response received over the connection.
     * @param context
     *            the context in which the connection is being used.
     * 
     * @return the duration in ms for which it is safe to keep the connection
     *         idle, or <=0 if no suggested duration.
     */
    long getKeepAliveDuration(HttpResponse response, HttpContext context);
    
}