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