1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
3 * ***** BEGIN LICENSE BLOCK *****
4 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6 * The contents of this file are subject to the Mozilla Public License Version
7 * 1.1 (the "License"); you may not use this file except in compliance with
8 * the License. You may obtain a copy of the License at
9 * http://www.mozilla.org/MPL/
11 * Software distributed under the License is distributed on an "AS IS" basis,
12 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13 * for the specific language governing rights and limitations under the
16 * The Original Code is nsDiskCacheBlockFile.h, released
19 * The Initial Developer of the Original Code is
20 * Netscape Communications Corporation.
21 * Portions created by the Initial Developer are Copyright (C) 2001
22 * the Initial Developer. All Rights Reserved.
25 * Gordon Sheridan <gordon@netscape.com>
27 * Alternatively, the contents of this file may be used under the terms of
28 * either the GNU General Public License Version 2 or later (the "GPL"), or
29 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
30 * in which case the provisions of the GPL or the LGPL are applicable instead
31 * of those above. If you wish to allow use of your version of this file only
32 * under the terms of either the GPL or the LGPL, and not to allow others to
33 * use your version of this file under the terms of the MPL, indicate your
34 * decision by deleting the provisions above and replace them with the notice
35 * and other provisions required by the GPL or the LGPL. If you do not delete
36 * the provisions above, a recipient may use your version of this file under
37 * the terms of any one of the MPL, the GPL or the LGPL.
39 * ***** END LICENSE BLOCK ***** */
41 #ifndef _nsDiskCacheBlockFile_h_
42 #define _nsDiskCacheBlockFile_h_
44 #include "nsILocalFile.h"
46 /******************************************************************************
47 * nsDiskCacheBlockFile
49 * The structure of a cache block file is a 4096 bytes bit map, followed by
50 * some number of blocks of mBlockSize. The creator of a
51 * nsDiskCacheBlockFile object must provide the block size for a given file.
53 *****************************************************************************/
54 class nsDiskCacheBlockFile
{
56 nsDiskCacheBlockFile()
62 , mBitMapDirty(PR_FALSE
)
64 ~nsDiskCacheBlockFile() { (void) Close(PR_TRUE
); }
66 nsresult
Open( nsILocalFile
* blockFile
, PRUint32 blockSize
,
68 nsresult
Close(PRBool flush
);
72 * Truncates the block file to the end of the last allocated block.
74 nsresult
Trim() { return nsDiskCache::Truncate(mFD
, CalcBlockFileSize()); }
75 nsresult
DeallocateBlocks( PRInt32 startBlock
, PRInt32 numBlocks
);
76 nsresult
WriteBlocks( void * buffer
, PRUint32 size
, PRInt32 numBlocks
,
77 PRInt32
* startBlock
);
78 nsresult
ReadBlocks( void * buffer
, PRInt32 startBlock
, PRInt32 numBlocks
,
82 nsresult
FlushBitMap();
83 PRInt32
AllocateBlocks( PRInt32 numBlocks
);
84 nsresult
VerifyAllocation( PRInt32 startBlock
, PRInt32 numBLocks
);
85 PRUint32
CalcBlockFileSize();
86 bool Write(PRInt32 offset
, const void *buf
, PRInt32 amount
);
92 PRUint32
* mBitMap
; // XXX future: array of bit map blocks
94 PRUint32 mBitMapWords
;
99 #endif // _nsDiskCacheBlockFile_h_