/* -*- Mode: C++; 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 nsCacheMetaData.h, released
 * February 22, 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>
 *
 * 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 ***** */

#ifndef _nsCacheMetaData_h_
#define _nsCacheMetaData_h_

#include "nspr.h"
#include "nscore.h"

class nsICacheMetaDataVisitor;

class nsCacheMetaData {
public:
    nsCacheMetaData() : mBuffer(nsnull), mBufferSize(0), mMetaSize(0) { }

    ~nsCacheMetaData() {
        mBufferSize = mMetaSize = 0;  
        PR_FREEIF(mBuffer);
    }

    const char *  GetElement(const char * key);

    nsresult      SetElement(const char * key, const char * value);

    PRUint32      Size(void) { return mMetaSize; }

    nsresult      FlattenMetaData(char * buffer, PRUint32 bufSize);

    nsresult      UnflattenMetaData(const char * buffer, PRUint32 bufSize);

    nsresult      VisitElements(nsICacheMetaDataVisitor * visitor);

private:
    nsresult      EnsureBuffer(PRUint32 size);

    char *        mBuffer;
    PRUint32      mBufferSize;
    PRUint32      mMetaSize;
};

#endif // _nsCacheMetaData_h