/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is nsICacheService.idl, released
 * February 10, 2001.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Gordon Sheridan <gordon@netscape.com>
 *   Patrick Beard   <beard@netscape.com>
 *   Darin Fisher    <darin@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"
#include "nsICache.idl"

interface nsISimpleEnumerator;
interface nsICacheListener;
interface nsICacheSession;
interface nsICacheVisitor;
interface nsIEventTarget;

[scriptable, uuid(14dbe1e9-f3bc-45af-92f4-2c574fcd4e39)]
interface nsICacheService : nsISupports
{
    /**
     * Create a cache session
     *
     * A cache session represents a client's access into the cache.  The cache
     * session is not "owned" by the cache service.  Hence, it is possible to
     * create duplicate cache sessions.  Entries created by a cache session
     * are invisible to other cache sessions, unless the cache sessions are
     * equivalent.
     *
     * @param clientID - Specifies the name of the client using the cache.
     * @param storagePolicy - Limits the storage policy for all entries
     *   accessed via the returned session.  As a result, devices excluded
     *   by the storage policy will not be searched when opening entries
     *   from the returned session.
     * @param streamBased - Indicates whether or not the data being cached
     *   can be represented as a stream.  The storagePolicy must be 
     *   consistent with the value of this field.  For example, a non-stream-
     *   based cache entry can only have a storage policy of STORE_IN_MEMORY.
     * @return new cache session.
     */
    nsICacheSession createSession(in string                 clientID,
                                  in nsCacheStoragePolicy   storagePolicy,
                                  in boolean                streamBased);

    /**
     * Visit entries stored in the cache.  Used to implement about:cache.
     */
    void visitEntries(in nsICacheVisitor visitor);

    /**
     * Evicts all entries in all devices implied by the storage policy.
     *
     * @note This function may evict some items but will throw if it fails to evict
     *       everything.
     */
    void evictEntries(in nsCacheStoragePolicy  storagePolicy);

    /**
     * Event target which is used for I/O operations
     */
    readonly attribute nsIEventTarget cacheIOTarget;
};

%{C++
/**
 * Observer service notification that is sent when
 * nsICacheService::evictEntries() or nsICacheSession::evictEntries()
 * is called.
 */
#define NS_CACHESERVICE_EMPTYCACHE_TOPIC_ID "cacheservice:empty-cache"
%}
