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fune/netwerk/cache/nsDiskCacheMap.h
Sylvestre Ledru 4e9cf83ee8 Bug 1378712 - Remove all trailing whitespaces r=Ehsan 
MozReview-Commit-ID: Kdz2xtTF9EG

--HG--
extra : rebase_source : 7235b3802f25bab29a8c6ba40a181a722f3df0ce
2017-07-06 14:00:35 +02:00

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 cin et: */
/* 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 _nsDiskCacheMap_h_
#define _nsDiskCacheMap_h_
#include "mozilla/MemoryReporting.h"
#include <limits.h>
#include "prnetdb.h"
#include "nsDebug.h"
#include "nsError.h"
#include "nsIFile.h"
#include "nsITimer.h"
#include "nsDiskCache.h"
#include "nsDiskCacheBlockFile.h"
class nsDiskCacheBinding;
struct nsDiskCacheEntry;
/******************************************************************************
* nsDiskCacheRecord
*
* Cache Location Format
*
* 1000 0000 0000 0000 0000 0000 0000 0000 : initialized bit
*
* 0011 0000 0000 0000 0000 0000 0000 0000 : File Selector (0 = separate file)
* 0000 0011 0000 0000 0000 0000 0000 0000 : number of extra contiguous blocks 1-4
* 0100 1100 0000 0000 0000 0000 0000 0000 : reserved bits
* 0000 0000 1111 1111 1111 1111 1111 1111 : block# 0-16777216 (2^24)
*
* 0000 0000 1111 1111 1111 1111 0000 0000 : eFileSizeMask (size of file in k: see note)
* 0000 0000 0000 0000 0000 0000 1111 1111 : eFileGenerationMask
*
* File Selector:
* 0 = separate file on disk
* 1 = 256 byte block file
* 2 = 1k block file
* 3 = 4k block file
*
* eFileSizeMask note: Files larger than 65535 KiB have this limit stored in
* the location. The file itself must be examined to
* determine its actual size if necessary.
*
*****************************************************************************/
/*
We have 3 block files with roughly the same max size (32MB)
1 - block size 256B, number of blocks 131072
2 - block size 1kB, number of blocks 32768
3 - block size 4kB, number of blocks 8192
*/
#define kNumBlockFiles 3
#define SIZE_SHIFT(idx) (2 * ((idx) - 1))
#define BLOCK_SIZE_FOR_INDEX(idx) ((idx) ? (256 << SIZE_SHIFT(idx)) : 0)
#define BITMAP_SIZE_FOR_INDEX(idx) ((idx) ? (131072 >> SIZE_SHIFT(idx)) : 0)
// Min and max values for the number of records in the DiskCachemap
#define kMinRecordCount 512
#define kSeparateFile 0
#define kBuckets (1 << 5) // must be a power of 2!
// Maximum size in K which can be stored in the location (see eFileSizeMask).
// Both data and metadata can be larger, but only up to kMaxDataSizeK can be
// counted into total cache size. I.e. if there are entries where either data or
// metadata is larger than kMaxDataSizeK, the total cache size will be
// inaccurate (smaller) than the actual cache size. The alternative is to stat
// the files to find the real size, which was decided against for performance
// reasons. See bug #651100 comment #21.
#define kMaxDataSizeK 0xFFFF
// preallocate up to 1MB of separate cache file
#define kPreallocateLimit 1 * 1024 * 1024
// The minimum amount of milliseconds to wait before re-attempting to
// revalidate the cache.
#define kRevalidateCacheTimeout 3000
#define kRevalidateCacheTimeoutTolerance 10
#define kRevalidateCacheErrorTimeout 1000
class nsDiskCacheRecord {
private:
uint32_t mHashNumber;
uint32_t mEvictionRank;
uint32_t mDataLocation;
uint32_t mMetaLocation;
enum {
eLocationInitializedMask = 0x80000000,
eLocationSelectorMask = 0x30000000,
eLocationSelectorOffset = 28,
eExtraBlocksMask = 0x03000000,
eExtraBlocksOffset = 24,
eReservedMask = 0x4C000000,
eBlockNumberMask = 0x00FFFFFF,
eFileSizeMask = 0x00FFFF00,
eFileSizeOffset = 8,
eFileGenerationMask = 0x000000FF,
eFileReservedMask = 0x4F000000
};
public:
nsDiskCacheRecord()
: mHashNumber(0), mEvictionRank(0), mDataLocation(0), mMetaLocation(0)
{
}
bool ValidRecord()
{
if ((mDataLocation & eReservedMask) || (mMetaLocation & eReservedMask))
return false;
return true;
}
// HashNumber accessors
uint32_t HashNumber() const { return mHashNumber; }
void SetHashNumber( uint32_t hashNumber) { mHashNumber = hashNumber; }
// EvictionRank accessors
uint32_t EvictionRank() const { return mEvictionRank; }
void SetEvictionRank( uint32_t rank) { mEvictionRank = rank ? rank : 1; }
// DataLocation accessors
bool DataLocationInitialized() const { return 0 != (mDataLocation & eLocationInitializedMask); }
void ClearDataLocation() { mDataLocation = 0; }
uint32_t DataFile() const
{
return (uint32_t)(mDataLocation & eLocationSelectorMask) >> eLocationSelectorOffset;
}
void SetDataBlocks( uint32_t index, uint32_t startBlock, uint32_t blockCount)
{
// clear everything
mDataLocation = 0;
// set file index
NS_ASSERTION( index < (kNumBlockFiles + 1), "invalid location index");
NS_ASSERTION( index > 0,"invalid location index");
mDataLocation |= (index << eLocationSelectorOffset) & eLocationSelectorMask;
// set startBlock
NS_ASSERTION(startBlock == (startBlock & eBlockNumberMask), "invalid block number");
mDataLocation |= startBlock & eBlockNumberMask;
// set blockCount
NS_ASSERTION( (blockCount>=1) && (blockCount<=4),"invalid block count");
--blockCount;
mDataLocation |= (blockCount << eExtraBlocksOffset) & eExtraBlocksMask;
mDataLocation |= eLocationInitializedMask;
}
uint32_t DataBlockCount() const
{
return (uint32_t)((mDataLocation & eExtraBlocksMask) >> eExtraBlocksOffset) + 1;
}
uint32_t DataStartBlock() const
{
return (mDataLocation & eBlockNumberMask);
}
uint32_t DataBlockSize() const
{
return BLOCK_SIZE_FOR_INDEX(DataFile());
}
uint32_t DataFileSize() const { return (mDataLocation & eFileSizeMask) >> eFileSizeOffset; }
void SetDataFileSize(uint32_t size)
{
NS_ASSERTION((mDataLocation & eFileReservedMask) == 0, "bad location");
mDataLocation &= ~eFileSizeMask; // clear eFileSizeMask
mDataLocation |= (size << eFileSizeOffset) & eFileSizeMask;
}
uint8_t DataFileGeneration() const
{
return (mDataLocation & eFileGenerationMask);
}
void SetDataFileGeneration( uint8_t generation)
{
// clear everything, (separate file index = 0)
mDataLocation = 0;
mDataLocation |= generation & eFileGenerationMask;
mDataLocation |= eLocationInitializedMask;
}
// MetaLocation accessors
bool MetaLocationInitialized() const { return 0 != (mMetaLocation & eLocationInitializedMask); }
void ClearMetaLocation() { mMetaLocation = 0; }
uint32_t MetaLocation() const { return mMetaLocation; }
uint32_t MetaFile() const
{
return (uint32_t)(mMetaLocation & eLocationSelectorMask) >> eLocationSelectorOffset;
}
void SetMetaBlocks( uint32_t index, uint32_t startBlock, uint32_t blockCount)
{
// clear everything
mMetaLocation = 0;
// set file index
NS_ASSERTION( index < (kNumBlockFiles + 1), "invalid location index");
NS_ASSERTION( index > 0, "invalid location index");
mMetaLocation |= (index << eLocationSelectorOffset) & eLocationSelectorMask;
// set startBlock
NS_ASSERTION(startBlock == (startBlock & eBlockNumberMask), "invalid block number");
mMetaLocation |= startBlock & eBlockNumberMask;
// set blockCount
NS_ASSERTION( (blockCount>=1) && (blockCount<=4),"invalid block count");
--blockCount;
mMetaLocation |= (blockCount << eExtraBlocksOffset) & eExtraBlocksMask;
mMetaLocation |= eLocationInitializedMask;
}
uint32_t MetaBlockCount() const
{
return (uint32_t)((mMetaLocation & eExtraBlocksMask) >> eExtraBlocksOffset) + 1;
}
uint32_t MetaStartBlock() const
{
return (mMetaLocation & eBlockNumberMask);
}
uint32_t MetaBlockSize() const
{
return BLOCK_SIZE_FOR_INDEX(MetaFile());
}
uint32_t MetaFileSize() const { return (mMetaLocation & eFileSizeMask) >> eFileSizeOffset; }
void SetMetaFileSize(uint32_t size)
{
mMetaLocation &= ~eFileSizeMask; // clear eFileSizeMask
mMetaLocation |= (size << eFileSizeOffset) & eFileSizeMask;
}
uint8_t MetaFileGeneration() const
{
return (mMetaLocation & eFileGenerationMask);
}
void SetMetaFileGeneration( uint8_t generation)
{
// clear everything, (separate file index = 0)
mMetaLocation = 0;
mMetaLocation |= generation & eFileGenerationMask;
mMetaLocation |= eLocationInitializedMask;
}
uint8_t Generation() const
{
if ((mDataLocation & eLocationInitializedMask) &&
(DataFile() == 0))
return DataFileGeneration();
if ((mMetaLocation & eLocationInitializedMask) &&
(MetaFile() == 0))
return MetaFileGeneration();
return 0; // no generation
}
#if defined(IS_LITTLE_ENDIAN)
void Swap()
{
mHashNumber = htonl(mHashNumber);
mEvictionRank = htonl(mEvictionRank);
mDataLocation = htonl(mDataLocation);
mMetaLocation = htonl(mMetaLocation);
}
#endif
#if defined(IS_LITTLE_ENDIAN)
void Unswap()
{
mHashNumber = ntohl(mHashNumber);
mEvictionRank = ntohl(mEvictionRank);
mDataLocation = ntohl(mDataLocation);
mMetaLocation = ntohl(mMetaLocation);
}
#endif
};
/******************************************************************************
* nsDiskCacheRecordVisitor
*****************************************************************************/
enum { kDeleteRecordAndContinue = -1,
kStopVisitingRecords = 0,
kVisitNextRecord = 1
};
class nsDiskCacheRecordVisitor {
public:
virtual int32_t VisitRecord( nsDiskCacheRecord * mapRecord) = 0;
};
/******************************************************************************
* nsDiskCacheHeader
*****************************************************************************/
struct nsDiskCacheHeader {
uint32_t mVersion; // cache version.
uint32_t mDataSize; // size of cache in units of 1024bytes.
int32_t mEntryCount; // number of entries stored in cache.
uint32_t mIsDirty; // dirty flag.
int32_t mRecordCount; // Number of records
uint32_t mEvictionRank[kBuckets]; // Highest EvictionRank of the bucket
uint32_t mBucketUsage[kBuckets]; // Number of used entries in the bucket
nsDiskCacheHeader()
: mVersion(nsDiskCache::kCurrentVersion)
, mDataSize(0)
, mEntryCount(0)
, mIsDirty(true)
, mRecordCount(0)
{}
void Swap()
{
#if defined(IS_LITTLE_ENDIAN)
mVersion = htonl(mVersion);
mDataSize = htonl(mDataSize);
mEntryCount = htonl(mEntryCount);
mIsDirty = htonl(mIsDirty);
mRecordCount = htonl(mRecordCount);
for (uint32_t i = 0; i < kBuckets ; i++) {
mEvictionRank[i] = htonl(mEvictionRank[i]);
mBucketUsage[i] = htonl(mBucketUsage[i]);
}
#endif
}
void Unswap()
{
#if defined(IS_LITTLE_ENDIAN)
mVersion = ntohl(mVersion);
mDataSize = ntohl(mDataSize);
mEntryCount = ntohl(mEntryCount);
mIsDirty = ntohl(mIsDirty);
mRecordCount = ntohl(mRecordCount);
for (uint32_t i = 0; i < kBuckets ; i++) {
mEvictionRank[i] = ntohl(mEvictionRank[i]);
mBucketUsage[i] = ntohl(mBucketUsage[i]);
}
#endif
}
};
/******************************************************************************
* nsDiskCacheMap
*****************************************************************************/
class nsDiskCacheMap {
public:
nsDiskCacheMap() :
mCacheDirectory(nullptr),
mMapFD(nullptr),
mCleanFD(nullptr),
mRecordArray(nullptr),
mBufferSize(0),
mBuffer(nullptr),
mMaxRecordCount(16384), // this default value won't matter
mIsDirtyCacheFlushed(false),
mLastInvalidateTime(0)
{ }
~nsDiskCacheMap()
{
(void) Close(true);
}
/**
* File Operations
*
* Open
*
* Creates a new cache map file if one doesn't exist.
* Returns error if it detects change in format or cache wasn't closed.
*/
nsresult Open( nsIFile * cacheDirectory,
nsDiskCache::CorruptCacheInfo * corruptInfo);
nsresult Close(bool flush);
nsresult Trim();
nsresult FlushHeader();
nsresult FlushRecords( bool unswap);
void NotifyCapacityChange(uint32_t capacity);
/**
* Record operations
*/
nsresult AddRecord( nsDiskCacheRecord * mapRecord, nsDiskCacheRecord * oldRecord);
nsresult UpdateRecord( nsDiskCacheRecord * mapRecord);
nsresult FindRecord( uint32_t hashNumber, nsDiskCacheRecord * mapRecord);
nsresult DeleteRecord( nsDiskCacheRecord * mapRecord);
nsresult VisitRecords( nsDiskCacheRecordVisitor * visitor);
nsresult EvictRecords( nsDiskCacheRecordVisitor * visitor);
/**
* Disk Entry operations
*/
nsresult DeleteStorage( nsDiskCacheRecord * record);
nsresult GetFileForDiskCacheRecord( nsDiskCacheRecord * record,
bool meta,
bool createPath,
nsIFile ** result);
nsresult GetLocalFileForDiskCacheRecord( nsDiskCacheRecord * record,
bool meta,
bool createPath,
nsIFile ** result);
// On success, this returns the buffer owned by nsDiskCacheMap,
// so it must not be deleted by the caller.
nsDiskCacheEntry * ReadDiskCacheEntry( nsDiskCacheRecord * record);
nsresult WriteDiskCacheEntry( nsDiskCacheBinding * binding);
nsresult ReadDataCacheBlocks(nsDiskCacheBinding * binding, char * buffer, uint32_t size);
nsresult WriteDataCacheBlocks(nsDiskCacheBinding * binding, char * buffer, uint32_t size);
nsresult DeleteStorage( nsDiskCacheRecord * record, bool metaData);
/**
* Statistical Operations
*/
void IncrementTotalSize( uint32_t delta)
{
mHeader.mDataSize += delta;
mHeader.mIsDirty = true;
}
void DecrementTotalSize( uint32_t delta)
{
NS_ASSERTION(mHeader.mDataSize >= delta, "disk cache size negative?");
mHeader.mDataSize = mHeader.mDataSize > delta ? mHeader.mDataSize - delta : 0;
mHeader.mIsDirty = true;
}
inline void IncrementTotalSize( uint32_t blocks, uint32_t blockSize)
{
// Round up to nearest K
IncrementTotalSize(((blocks*blockSize) + 0x03FF) >> 10);
}
inline void DecrementTotalSize( uint32_t blocks, uint32_t blockSize)
{
// Round up to nearest K
DecrementTotalSize(((blocks*blockSize) + 0x03FF) >> 10);
}
uint32_t TotalSize() { return mHeader.mDataSize; }
int32_t EntryCount() { return mHeader.mEntryCount; }
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf);
private:
/**
* Private methods
*/
nsresult OpenBlockFiles(nsDiskCache::CorruptCacheInfo * corruptInfo);
nsresult CloseBlockFiles(bool flush);
bool CacheFilesExist();
nsresult CreateCacheSubDirectories();
uint32_t CalculateFileIndex(uint32_t size);
nsresult GetBlockFileForIndex( uint32_t index, nsIFile ** result);
uint32_t GetBlockSizeForIndex( uint32_t index) const {
return BLOCK_SIZE_FOR_INDEX(index);
}
uint32_t GetBitMapSizeForIndex( uint32_t index) const {
return BITMAP_SIZE_FOR_INDEX(index);
}
// returns the bucket number
uint32_t GetBucketIndex( uint32_t hashNumber) const {
return (hashNumber & (kBuckets - 1));
}
// Gets the size of the bucket (in number of records)
uint32_t GetRecordsPerBucket() const {
return mHeader.mRecordCount / kBuckets;
}
// Gets the first record in the bucket
nsDiskCacheRecord *GetFirstRecordInBucket(uint32_t bucket) const {
return mRecordArray + bucket * GetRecordsPerBucket();
}
uint32_t GetBucketRank(uint32_t bucketIndex, uint32_t targetRank);
int32_t VisitEachRecord(uint32_t bucketIndex,
nsDiskCacheRecordVisitor * visitor,
uint32_t evictionRank);
nsresult GrowRecords();
nsresult ShrinkRecords();
nsresult EnsureBuffer(uint32_t bufSize);
// The returned structure will point to the buffer owned by nsDiskCacheMap,
// so it must not be deleted by the caller.
nsDiskCacheEntry * CreateDiskCacheEntry(nsDiskCacheBinding * binding,
uint32_t * size);
// Initializes the _CACHE_CLEAN_ related functionality
nsresult InitCacheClean(nsIFile * cacheDirectory,
nsDiskCache::CorruptCacheInfo * corruptInfo);
// Writes out a value of '0' or '1' in the _CACHE_CLEAN_ file
nsresult WriteCacheClean(bool clean);
// Resets the timout for revalidating the cache
nsresult ResetCacheTimer(int32_t timeout = kRevalidateCacheTimeout);
// Invalidates the cache, calls WriteCacheClean and ResetCacheTimer
nsresult InvalidateCache();
// Determines if the cache is in a safe state
bool IsCacheInSafeState();
// Revalidates the cache by writting out the header, records, and finally
// by calling WriteCacheClean(true).
nsresult RevalidateCache();
// Timer which revalidates the cache
static void RevalidateTimerCallback(nsITimer *aTimer, void *arg);
/**
* data members
*/
private:
nsCOMPtr<nsITimer> mCleanCacheTimer;
nsCOMPtr<nsIFile> mCacheDirectory;
PRFileDesc * mMapFD;
PRFileDesc * mCleanFD;
nsDiskCacheRecord * mRecordArray;
nsDiskCacheBlockFile mBlockFile[kNumBlockFiles];
uint32_t mBufferSize;
char * mBuffer;
nsDiskCacheHeader mHeader;
int32_t mMaxRecordCount;
bool mIsDirtyCacheFlushed;
PRIntervalTime mLastInvalidateTime;
};
#endif // _nsDiskCacheMap_h_
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