package org.bouncycastle.jce.cert;

/**
 * A specification of <code>CertStore</code> parameters.<br />
 * <br />
 * The purpose of this interface is to group (and provide type safety for) 
 * all <code>CertStore</code> parameter specifications. All 
 * <code>CertStore</code> parameter specifications must implement this 
 * interface.  <br />
 * <br />
 * Typically, a <code>CertStoreParameters</code> object is passed as a parameter
 * to one of the {@link CertStore#getInstance CertStore.getInstance} methods. 
 * The <code>getInstance</code> method returns a <code>CertStore</code> that
 * is used for retrieving <code>Certificate</code>s and <code>CRL</code>s. The 
 * <code>CertStore</code> that is returned is initialized with the specified 
 * parameters. The type of parameters needed may vary between different types 
 * of <code>CertStore</code>s.
 *
 * @see CertStore#getInstance
 **/
public interface CertStoreParameters extends Cloneable
{
	/**
	 * Makes a copy of this <code>CertStoreParameters</code>.<br />
	 * <br />
	 * The precise meaning of "copy" may depend on the class of 
	 * the <code>CertStoreParameters</code> object. A typical implementation 
	 * performs a "deep copy" of this object, but this is not an absolute 
	 * requirement. Some implementations may perform a "shallow copy" of some 
	 * or all of the fields of this object.<br />
	 * <br />
	 * Note that the <code>CertStore.getInstance</code> methods make a copy
	 * of the specified <code>CertStoreParameters</code>. A deep copy
	 * implementation of <code>clone</code> is safer and more robust, as it 
	 * prevents the caller from corrupting a shared <code>CertStore</code> by
	 * subsequently modifying the contents of its initialization parameters. 
	 * However, a shallow copy implementation of <code>clone</code> is more 
	 * appropriate for applications that need to hold a reference to a
	 * parameter contained in the <code>CertStoreParameters</code>. For example,
	 * a shallow copy clone allows an application to release the resources of 
	 * a particular <code>CertStore</code> initialization parameter immediately,
	 * rather than waiting for the garbage collection mechanism. This should 
	 * be done with the utmost care, since the <code>CertStore</code> may still 
	 * be in use by other threads.<br />
	 * <br />
	 * Each subclass should state the precise behavior of this method so
	 * that users and developers know what to expect.
	 *
	 * @return a copy of this <code>CertStoreParameters</code>
	 */
    public Object clone();
}
