michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* vim: set sw=4 ts=8 et tw=80 : */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef _nsDiskCacheBlockFile_h_
michael@0: #define _nsDiskCacheBlockFile_h_
michael@0: 
michael@0: #include "mozilla/MemoryReporting.h"
michael@0: #include "nsIFile.h"
michael@0: #include "nsDiskCache.h"
michael@0: 
michael@0: /******************************************************************************
michael@0:  *  nsDiskCacheBlockFile
michael@0:  *
michael@0:  *  The structure of a cache block file is a 4096 bytes bit map, followed by
michael@0:  *  some number of blocks of mBlockSize.  The creator of a
michael@0:  *  nsDiskCacheBlockFile object must provide the block size for a given file.
michael@0:  *
michael@0:  *****************************************************************************/
michael@0: class nsDiskCacheBlockFile {
michael@0: public:
michael@0:     nsDiskCacheBlockFile()
michael@0:            : mFD(nullptr)
michael@0:            , mBitMap(nullptr)
michael@0:            , mBlockSize(0)
michael@0:            , mBitMapWords(0)
michael@0:            , mFileSize(0)
michael@0:            , mBitMapDirty(false)
michael@0:             {}
michael@0:     ~nsDiskCacheBlockFile() { (void) Close(true); }
michael@0:     
michael@0:     nsresult  Open( nsIFile *  blockFile, uint32_t  blockSize,
michael@0:                     uint32_t  bitMapSize, nsDiskCache::CorruptCacheInfo *  corruptInfo);
michael@0:     nsresult  Close(bool flush);
michael@0: 
michael@0:     /*
michael@0:      * Trim
michael@0:      * Truncates the block file to the end of the last allocated block.
michael@0:      */
michael@0:     nsresult  Trim() { return nsDiskCache::Truncate(mFD, CalcBlockFileSize()); }
michael@0:     nsresult  DeallocateBlocks( int32_t  startBlock, int32_t  numBlocks);
michael@0:     nsresult  WriteBlocks( void * buffer, uint32_t size, int32_t  numBlocks, 
michael@0:                            int32_t * startBlock);
michael@0:     nsresult  ReadBlocks( void * buffer, int32_t  startBlock, int32_t  numBlocks, 
michael@0:                           int32_t * bytesRead);
michael@0: 
michael@0:     size_t   SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf);
michael@0: 
michael@0: private:
michael@0:     nsresult  FlushBitMap();
michael@0:     int32_t   AllocateBlocks( int32_t  numBlocks);
michael@0:     nsresult  VerifyAllocation( int32_t startBlock, int32_t numBLocks);
michael@0:     uint32_t  CalcBlockFileSize();
michael@0:     bool   Write(int32_t offset, const void *buf, int32_t amount);
michael@0: 
michael@0: /**
michael@0:  *  Data members
michael@0:  */
michael@0:     PRFileDesc *                mFD;
michael@0:     uint32_t *                  mBitMap;      // XXX future: array of bit map blocks
michael@0:     uint32_t                    mBlockSize;
michael@0:     uint32_t                    mBitMapWords;
michael@0:     int32_t                     mFileSize;
michael@0:     bool                        mBitMapDirty;
michael@0: };
michael@0: 
michael@0: #endif // _nsDiskCacheBlockFile_h_