1 // Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of the License "Eclipse Public License v1.0"

     5 // which accompanies this distribution, and is available

     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 // f32\sfile\sf_file_cache_defs.h

    15 // This file contains default settings for file caching. 

    16 // Some of these settings may be overriden by appropriate entries in the estart.txt file

    17 // Sizes / lengths specified in kilobytes, timeouts in miliseconds

    18 // 

    19 //

    20 

    21 /**

    22  @file

    23  @internalTechnology

    24 */

    25 

    26 

    27 // Global file-cache settings 

    28 const TBool KDefaultGlobalCacheEnabled			= ETrue; 

    29 const TInt KDefaultGlobalCacheSize				= (32*1024);	// 32768 K = 32 MBytes - the maximum for all files

    30 // The maximum amount of locked data allowed for all files

    31 const TInt KDefaultGlobalCacheMaxLockedSize	= (1*1024);		// 1 Mb maximum locked data

    32 // Low memory threshold as a percentage of total RAM.

    33 // If the amount of RAM drops below this value, attempts to allocate memory for a file caching will fail

    34 const TInt KDefaultLowMemoryThreshold			= 10;			// 10 % of total RAM

    35 

    36 // per-drive file-cache settings. 

    37 const TInt KDefaultFileCacheMaxReadAheadLen	= (128);	// 128K	// NB non-configurable by estart

    38 const TInt KDefaultFileCacheSize				= (256);	// 256K

    39 const TInt KDefaultFairSchedulingLen			= (128);	// 128K

    40 

    41 

    42 enum {EFileCacheFlagOff, EFileCacheFlagEnabled, EFileCacheFlagOn};

    43 

    44 // default drive cache settings - these may be overridden by estart.txt settings or file open mode 

    45 

    46 const TInt KDefaultFileCacheRead				= EFileCacheFlagEnabled;

    47 const TInt KDefaultFileCacheReadAhead			= EFileCacheFlagOn;		// NB only enabled if read caching also enabled

    48 const TInt KDefaultFileCacheWrite				= EFileCacheFlagEnabled;

    49 

    50 /**

    51 If set to ETrue, media driver reads on this drive are considered to be asynchronous 

    52 i.e. interrupt driven. This results in read-aheads being issued before completing a client read request.

    53 

    54 If set to EFalse, media driver reads on this drive are considered to be synchronous 

    55 i.e. issuing a read-ahead is likely to block any client thread which will normally be running at

    56 lower priority than the media driver's thread. In this case read-aheads only happen during periods 

    57 of inactivity so as to improve latency: this is achieved by lowering the process of the drive thread

    58 if there is only one read-ahead request in the drive thread's queue.

    59 */

    60 const TInt KDefaultFileCacheReadAsync			= ETrue;

    61  

    62 // time after which a file will be removed from closed file queue

    63 const TInt KDefaultClosedFileKeepAliveTime = 3000;			// 3,000 ms = 3 seconds

    64 

    65 // time after which a file containing dirty data will be flushed

    66 const TInt KDefaultDirtyDataFlushTime = 3000;				// 3,000 ms = 3 seconds

    67