1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 : *
3 : * ***** BEGIN LICENSE BLOCK *****
4 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
5 : *
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/
10 : *
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
14 : * License.
15 : *
16 : * The Original Code is nsDiskCacheBlockFile.h, released
17 : * April 12, 2001.
18 : *
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.
23 : *
24 : * Contributor(s):
25 : * Gordon Sheridan <gordon@netscape.com>
26 : *
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.
38 : *
39 : * ***** END LICENSE BLOCK ***** */
40 :
41 : #ifndef _nsDiskCacheBlockFile_h_
42 : #define _nsDiskCacheBlockFile_h_
43 :
44 : #include "nsILocalFile.h"
45 :
46 : /******************************************************************************
47 : * nsDiskCacheBlockFile
48 : *
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.
52 : *
53 : *****************************************************************************/
54 : class nsDiskCacheBlockFile {
55 : public:
56 525 : nsDiskCacheBlockFile()
57 : : mFD(nsnull)
58 : , mBitMap(nsnull)
59 : , mBlockSize(0)
60 : , mBitMapWords(0)
61 : , mFileSize(0)
62 525 : , mBitMapDirty(false)
63 525 : {}
64 525 : ~nsDiskCacheBlockFile() { (void) Close(true); }
65 :
66 : nsresult Open( nsILocalFile * blockFile, PRUint32 blockSize,
67 : PRUint32 bitMapSize);
68 : nsresult Close(bool flush);
69 :
70 : /*
71 : * Trim
72 : * Truncates the block file to the end of the last allocated block.
73 : */
74 0 : 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,
79 : PRInt32 * bytesRead);
80 :
81 : private:
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);
87 :
88 : /**
89 : * Data members
90 : */
91 : PRFileDesc * mFD;
92 : PRUint32 * mBitMap; // XXX future: array of bit map blocks
93 : PRUint32 mBlockSize;
94 : PRUint32 mBitMapWords;
95 : PRInt32 mFileSize;
96 : bool mBitMapDirty;
97 : };
98 :
99 : #endif // _nsDiskCacheBlockFile_h_
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