gecko-dev/netwerk/cache/src/nsMemoryCacheDevice.h

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * 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 nsMemoryCacheDevice.h, released February 20, 2001.
 * 
 * The Initial Developer of the Original Code is Netscape Communications
 * Corporation.  Portions created by Netscape are
 * Copyright (C) 2001 Netscape Communications Corporation.  All
 * Rights Reserved.
 * 
 * Contributor(s): 
 *    Gordon Sheridan, 20-February-2001
 */

#ifndef _nsMemoryCacheDevice_h_
#define _nsMemoryCacheDevice_h_

#include "nsCacheDevice.h"
#include "pldhash.h"
#include "nsCacheEntry.h"



class nsMemoryCacheDevice : public nsCacheDevice
{
public:
    nsMemoryCacheDevice();
    virtual ~nsMemoryCacheDevice();

    virtual nsresult  Init();

    virtual const char *   GetDeviceID(void);
    virtual nsCacheEntry * FindEntry( nsCString * key );
    virtual nsresult       DeactivateEntry( nsCacheEntry * entry );
    virtual nsresult       BindEntry( nsCacheEntry * entry );
    virtual void           DoomEntry( nsCacheEntry * entry );

    virtual nsresult GetTransportForEntry( nsCacheEntry * entry,
                                           nsCacheAccessMode mode,
                                           nsITransport **transport );

    virtual nsresult GetFileForEntry( nsCacheEntry *    entry,
                                      nsIFile **        result );

    virtual nsresult OnDataSizeChange( nsCacheEntry * entry, PRInt32 deltaSize );

    virtual nsresult Visit( nsICacheVisitor * visitor );
    
    static int PR_CALLBACK MemoryCacheSizeChanged(const char * pref, void * closure);
 
private:
    nsresult  AdjustMemoryLimits(PRUint32  softLimit, PRUint32  hardLimit);
    nsresult  EvictEntries(void);

    nsCacheEntryHashTable   mMemCacheEntries;
    PRCList                 mEvictionList;

    PRUint32                mHardLimit;
    PRUint32                mSoftLimit;

    PRUint32                mTotalSize;
    PRUint32                mInactiveSize;

    PRUint32                mEntryCount;

    PRUint32                mMaxEntryCount;
    // XXX what other stats do we want to keep?
};


#endif // _nsMemoryCacheDevice_h_