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gecko-dev/netwerk/cache2/CacheIndex.h

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/* 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 CacheIndex__h__
#define CacheIndex__h__
#include "CacheLog.h"
#include "CacheFileIOManager.h"
#include "nsIRunnable.h"
#include "CacheHashUtils.h"
#include "nsICacheStorageService.h"
#include "nsICacheEntry.h"
#include "nsILoadContextInfo.h"
#include "nsTHashtable.h"
#include "nsThreadUtils.h"
#include "nsWeakReference.h"
#include "mozilla/SHA1.h"
#include "mozilla/Mutex.h"
#include "mozilla/Endian.h"
#include "mozilla/TimeStamp.h"
class nsIFile;
class nsIDirectoryEnumerator;
class nsITimer;
#ifdef DEBUG
#define DEBUG_STATS 1
#endif
namespace mozilla {
namespace net {
class CacheFileMetadata;
class FileOpenHelper;
class CacheIndexIterator;
typedef struct {
// Version of the index. The index must be ignored and deleted when the file
// on disk was written with a newer version.
uint32_t mVersion;
// Timestamp of time when the last successful write of the index started.
// During update process we use this timestamp for a quick validation of entry
// files. If last modified time of the file is lower than this timestamp, we
// skip parsing of such file since the information in index should be up to
// date.
uint32_t mTimeStamp;
// We set this flag as soon as possible after parsing index during startup
// and clean it after we write journal to disk during shutdown. We ignore the
// journal and start update process whenever this flag is set during index
// parsing.
uint32_t mIsDirty;
} CacheIndexHeader;
struct CacheIndexRecord {
SHA1Sum::Hash mHash;
uint32_t mFrecency;
uint32_t mExpirationTime;
uint32_t mAppId;
/*
* 1000 0000 0000 0000 0000 0000 0000 0000 : initialized
* 0100 0000 0000 0000 0000 0000 0000 0000 : anonymous
* 0010 0000 0000 0000 0000 0000 0000 0000 : inBrowser
* 0001 0000 0000 0000 0000 0000 0000 0000 : removed
* 0000 1000 0000 0000 0000 0000 0000 0000 : dirty
* 0000 0100 0000 0000 0000 0000 0000 0000 : fresh
* 0000 0011 0000 0000 0000 0000 0000 0000 : reserved
* 0000 0000 1111 1111 1111 1111 1111 1111 : file size (in kB)
*/
uint32_t mFlags;
CacheIndexRecord()
: mFrecency(0)
, mExpirationTime(nsICacheEntry::NO_EXPIRATION_TIME)
, mAppId(nsILoadContextInfo::NO_APP_ID)
, mFlags(0)
{}
};
class CacheIndexEntry : public PLDHashEntryHdr
{
public:
typedef const SHA1Sum::Hash& KeyType;
typedef const SHA1Sum::Hash* KeyTypePointer;
CacheIndexEntry(KeyTypePointer aKey)
{
MOZ_COUNT_CTOR(CacheIndexEntry);
mRec = new CacheIndexRecord();
LOG(("CacheIndexEntry::CacheIndexEntry() - Created record [rec=%p]", mRec.get()));
memcpy(&mRec->mHash, aKey, sizeof(SHA1Sum::Hash));
}
CacheIndexEntry(const CacheIndexEntry& aOther)
{
NS_NOTREACHED("CacheIndexEntry copy constructor is forbidden!");
}
~CacheIndexEntry()
{
MOZ_COUNT_DTOR(CacheIndexEntry);
LOG(("CacheIndexEntry::~CacheIndexEntry() - Deleting record [rec=%p]",
mRec.get()));
}
// KeyEquals(): does this entry match this key?
bool KeyEquals(KeyTypePointer aKey) const
{
return memcmp(&mRec->mHash, aKey, sizeof(SHA1Sum::Hash)) == 0;
}
// KeyToPointer(): Convert KeyType to KeyTypePointer
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
// HashKey(): calculate the hash number
static PLDHashNumber HashKey(KeyTypePointer aKey)
{
return (reinterpret_cast<const uint32_t *>(aKey))[0];
}
// ALLOW_MEMMOVE can we move this class with memmove(), or do we have
// to use the copy constructor?
enum { ALLOW_MEMMOVE = true };
bool operator==(const CacheIndexEntry& aOther) const
{
return KeyEquals(&aOther.mRec->mHash);
}
CacheIndexEntry& operator=(const CacheIndexEntry& aOther)
{
MOZ_ASSERT(memcmp(&mRec->mHash, &aOther.mRec->mHash,
sizeof(SHA1Sum::Hash)) == 0);
mRec->mFrecency = aOther.mRec->mFrecency;
mRec->mExpirationTime = aOther.mRec->mExpirationTime;
mRec->mAppId = aOther.mRec->mAppId;
mRec->mFlags = aOther.mRec->mFlags;
return *this;
}
void InitNew()
{
mRec->mFrecency = 0;
mRec->mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME;
mRec->mAppId = nsILoadContextInfo::NO_APP_ID;
mRec->mFlags = 0;
}
void Init(uint32_t aAppId, bool aAnonymous, bool aInBrowser)
{
MOZ_ASSERT(mRec->mFrecency == 0);
MOZ_ASSERT(mRec->mExpirationTime == nsICacheEntry::NO_EXPIRATION_TIME);
MOZ_ASSERT(mRec->mAppId == nsILoadContextInfo::NO_APP_ID);
// When we init the entry it must be fresh and may be dirty
MOZ_ASSERT((mRec->mFlags & ~kDirtyMask) == kFreshMask);
mRec->mAppId = aAppId;
mRec->mFlags |= kInitializedMask;
if (aAnonymous) {
mRec->mFlags |= kAnonymousMask;
}
if (aInBrowser) {
mRec->mFlags |= kInBrowserMask;
}
}
const SHA1Sum::Hash * Hash() { return &mRec->mHash; }
bool IsInitialized() { return !!(mRec->mFlags & kInitializedMask); }
uint32_t AppId() { return mRec->mAppId; }
bool Anonymous() { return !!(mRec->mFlags & kAnonymousMask); }
bool InBrowser() { return !!(mRec->mFlags & kInBrowserMask); }
bool IsRemoved() { return !!(mRec->mFlags & kRemovedMask); }
void MarkRemoved() { mRec->mFlags |= kRemovedMask; }
bool IsDirty() { return !!(mRec->mFlags & kDirtyMask); }
void MarkDirty() { mRec->mFlags |= kDirtyMask; }
void ClearDirty() { mRec->mFlags &= ~kDirtyMask; }
bool IsFresh() { return !!(mRec->mFlags & kFreshMask); }
void MarkFresh() { mRec->mFlags |= kFreshMask; }
void SetFrecency(uint32_t aFrecency) { mRec->mFrecency = aFrecency; }
uint32_t GetFrecency() { return mRec->mFrecency; }
void SetExpirationTime(uint32_t aExpirationTime)
{
mRec->mExpirationTime = aExpirationTime;
}
uint32_t GetExpirationTime() { return mRec->mExpirationTime; }
// Sets filesize in kilobytes.
void SetFileSize(uint32_t aFileSize)
{
if (aFileSize > kFileSizeMask) {
LOG(("CacheIndexEntry::SetFileSize() - FileSize is too large, "
"truncating to %u", kFileSizeMask));
aFileSize = kFileSizeMask;
}
mRec->mFlags &= ~kFileSizeMask;
mRec->mFlags |= aFileSize;
}
// Returns filesize in kilobytes.
uint32_t GetFileSize() { return GetFileSize(mRec); }
static uint32_t GetFileSize(CacheIndexRecord *aRec)
{
return aRec->mFlags & kFileSizeMask;
}
bool IsFileEmpty() { return GetFileSize() == 0; }
void WriteToBuf(void *aBuf)
{
CacheIndexRecord *dst = reinterpret_cast<CacheIndexRecord *>(aBuf);
// Copy the whole record to the buffer.
memcpy(aBuf, mRec, sizeof(CacheIndexRecord));
// Dirty and fresh flags should never go to disk, since they make sense only
// during current session.
dst->mFlags &= ~kDirtyMask;
dst->mFlags &= ~kFreshMask;
#if defined(IS_LITTLE_ENDIAN)
// Data in the buffer are in machine byte order and we want them in network
// byte order.
NetworkEndian::writeUint32(&dst->mFrecency, dst->mFrecency);
NetworkEndian::writeUint32(&dst->mExpirationTime, dst->mExpirationTime);
NetworkEndian::writeUint32(&dst->mAppId, dst->mAppId);
NetworkEndian::writeUint32(&dst->mFlags, dst->mFlags);
#endif
}
void ReadFromBuf(void *aBuf)
{
CacheIndexRecord *src= reinterpret_cast<CacheIndexRecord *>(aBuf);
MOZ_ASSERT(memcmp(&mRec->mHash, &src->mHash,
sizeof(SHA1Sum::Hash)) == 0);
mRec->mFrecency = NetworkEndian::readUint32(&src->mFrecency);
mRec->mExpirationTime = NetworkEndian::readUint32(&src->mExpirationTime);
mRec->mAppId = NetworkEndian::readUint32(&src->mAppId);
mRec->mFlags = NetworkEndian::readUint32(&src->mFlags);
}
void Log() {
LOG(("CacheIndexEntry::Log() [this=%p, hash=%08x%08x%08x%08x%08x, fresh=%u,"
" initialized=%u, removed=%u, dirty=%u, anonymous=%u, inBrowser=%u, "
"appId=%u, frecency=%u, expirationTime=%u, size=%u]",
this, LOGSHA1(mRec->mHash), IsFresh(), IsInitialized(), IsRemoved(),
IsDirty(), Anonymous(), InBrowser(), AppId(), GetFrecency(),
GetExpirationTime(), GetFileSize()));
}
static bool RecordMatchesLoadContextInfo(CacheIndexRecord *aRec,
nsILoadContextInfo *aInfo)
{
if (!aInfo->IsPrivate() &&
aInfo->AppId() == aRec->mAppId &&
aInfo->IsAnonymous() == !!(aRec->mFlags & kAnonymousMask) &&
aInfo->IsInBrowserElement() == !!(aRec->mFlags & kInBrowserMask)) {
return true;
}
return false;
}
// Memory reporting
size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
{
return mallocSizeOf(mRec.get());
}
size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
{
return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
}
private:
friend class CacheIndex;
friend class CacheIndexEntryAutoManage;
static const uint32_t kInitializedMask = 0x80000000;
static const uint32_t kAnonymousMask = 0x40000000;
static const uint32_t kInBrowserMask = 0x20000000;
// This flag is set when the entry was removed. We need to keep this
// information in memory until we write the index file.
static const uint32_t kRemovedMask = 0x10000000;
// This flag is set when the information in memory is not in sync with the
// information in index file on disk.
static const uint32_t kDirtyMask = 0x08000000;
// This flag is set when the information about the entry is fresh, i.e.
// we've created or opened this entry during this session, or we've seen
// this entry during update or build process.
static const uint32_t kFreshMask = 0x04000000;
static const uint32_t kReservedMask = 0x03000000;
// FileSize in kilobytes
static const uint32_t kFileSizeMask = 0x00FFFFFF;
nsAutoPtr<CacheIndexRecord> mRec;
};
class CacheIndexStats
{
public:
CacheIndexStats()
: mCount(0)
, mNotInitialized(0)
, mRemoved(0)
, mDirty(0)
, mFresh(0)
, mEmpty(0)
, mSize(0)
#ifdef DEBUG
, mStateLogged(false)
, mDisableLogging(false)
#endif
{
}
bool operator==(const CacheIndexStats& aOther) const
{
return
#ifdef DEBUG
aOther.mStateLogged == mStateLogged &&
#endif
aOther.mCount == mCount &&
aOther.mNotInitialized == mNotInitialized &&
aOther.mRemoved == mRemoved &&
aOther.mDirty == mDirty &&
aOther.mFresh == mFresh &&
aOther.mEmpty == mEmpty &&
aOther.mSize == mSize;
}
#ifdef DEBUG
void DisableLogging() {
mDisableLogging = true;
}
#endif
void Log() {
LOG(("CacheIndexStats::Log() [count=%u, notInitialized=%u, removed=%u, "
"dirty=%u, fresh=%u, empty=%u, size=%u]", mCount, mNotInitialized,
mRemoved, mDirty, mFresh, mEmpty, mSize));
}
void Clear() {
MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Clear() - state logged!");
mCount = 0;
mNotInitialized = 0;
mRemoved = 0;
mDirty = 0;
mFresh = 0;
mEmpty = 0;
mSize = 0;
}
#ifdef DEBUG
bool StateLogged() {
return mStateLogged;
}
#endif
uint32_t Count() {
MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Count() - state logged!");
return mCount;
}
uint32_t Dirty() {
MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Dirty() - state logged!");
return mDirty;
}
uint32_t Fresh() {
MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Fresh() - state logged!");
return mFresh;
}
uint32_t ActiveEntriesCount() {
MOZ_ASSERT(!mStateLogged, "CacheIndexStats::ActiveEntriesCount() - state "
"logged!");
return mCount - mRemoved - mNotInitialized - mEmpty;
}
uint32_t Size() {
MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Size() - state logged!");
return mSize;
}
void BeforeChange(CacheIndexEntry *aEntry) {
#ifdef DEBUG_STATS
if (!mDisableLogging) {
LOG(("CacheIndexStats::BeforeChange()"));
Log();
}
#endif
MOZ_ASSERT(!mStateLogged, "CacheIndexStats::BeforeChange() - state "
"logged!");
#ifdef DEBUG
mStateLogged = true;
#endif
if (aEntry) {
MOZ_ASSERT(mCount);
mCount--;
if (aEntry->IsDirty()) {
MOZ_ASSERT(mDirty);
mDirty--;
}
if (aEntry->IsFresh()) {
MOZ_ASSERT(mFresh);
mFresh--;
}
if (aEntry->IsRemoved()) {
MOZ_ASSERT(mRemoved);
mRemoved--;
} else {
if (!aEntry->IsInitialized()) {
MOZ_ASSERT(mNotInitialized);
mNotInitialized--;
} else {
if (aEntry->IsFileEmpty()) {
MOZ_ASSERT(mEmpty);
mEmpty--;
} else {
MOZ_ASSERT(mSize >= aEntry->GetFileSize());
mSize -= aEntry->GetFileSize();
}
}
}
}
}
void AfterChange(CacheIndexEntry *aEntry) {
MOZ_ASSERT(mStateLogged, "CacheIndexStats::AfterChange() - state not "
"logged!");
#ifdef DEBUG
mStateLogged = false;
#endif
if (aEntry) {
++mCount;
if (aEntry->IsDirty()) {
mDirty++;
}
if (aEntry->IsFresh()) {
mFresh++;
}
if (aEntry->IsRemoved()) {
mRemoved++;
} else {
if (!aEntry->IsInitialized()) {
mNotInitialized++;
} else {
if (aEntry->IsFileEmpty()) {
mEmpty++;
} else {
mSize += aEntry->GetFileSize();
}
}
}
}
#ifdef DEBUG_STATS
if (!mDisableLogging) {
LOG(("CacheIndexStats::AfterChange()"));
Log();
}
#endif
}
private:
uint32_t mCount;
uint32_t mNotInitialized;
uint32_t mRemoved;
uint32_t mDirty;
uint32_t mFresh;
uint32_t mEmpty;
uint32_t mSize;
#ifdef DEBUG
// We completely remove the data about an entry from the stats in
// BeforeChange() and set this flag to true. The entry is then modified,
// deleted or created and the data is again put into the stats and this flag
// set to false. Statistics must not be read during this time since the
// information is not correct.
bool mStateLogged;
// Disables logging in this instance of CacheIndexStats
bool mDisableLogging;
#endif
};
class CacheIndex : public CacheFileIOListener
, public nsIRunnable
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIRUNNABLE
CacheIndex();
static nsresult Init(nsIFile *aCacheDirectory);
static nsresult PreShutdown();
static nsresult Shutdown();
// Following methods can be called only on IO thread.
// Add entry to the index. The entry shouldn't be present in index. This
// method is called whenever a new handle for a new entry file is created. The
// newly created entry is not initialized and it must be either initialized
// with InitEntry() or removed with RemoveEntry().
static nsresult AddEntry(const SHA1Sum::Hash *aHash);
// Inform index about an existing entry that should be present in index. This
// method is called whenever a new handle for an existing entry file is
// created. Like in case of AddEntry(), either InitEntry() or RemoveEntry()
// must be called on the entry, since the entry is not initizlized if the
// index is outdated.
static nsresult EnsureEntryExists(const SHA1Sum::Hash *aHash);
// Initialize the entry. It MUST be present in index. Call to AddEntry() or
// EnsureEntryExists() must precede the call to this method.
static nsresult InitEntry(const SHA1Sum::Hash *aHash,
uint32_t aAppId,
bool aAnonymous,
bool aInBrowser);
// Remove entry from index. The entry should be present in index.
static nsresult RemoveEntry(const SHA1Sum::Hash *aHash);
// Update some information in entry. The entry MUST be present in index and
// MUST be initialized. Call to AddEntry() or EnsureEntryExists() and to
// InitEntry() must precede the call to this method.
// Pass nullptr if the value didn't change.
static nsresult UpdateEntry(const SHA1Sum::Hash *aHash,
const uint32_t *aFrecency,
const uint32_t *aExpirationTime,
const uint32_t *aSize);
// Remove all entries from the index. Called when clearing the whole cache.
static nsresult RemoveAll();
enum EntryStatus {
EXISTS = 0,
DOES_NOT_EXIST = 1,
DO_NOT_KNOW = 2
};
// Returns status of the entry in index for the given key. It can be called
// on any thread.
static nsresult HasEntry(const nsACString &aKey, EntryStatus *_retval);
// Returns a hash of the least important entry that should be evicted if the
// cache size is over limit and also returns a total number of all entries in
// the index minus the number of forced valid entries that we encounter
// when searching (see below)
static nsresult GetEntryForEviction(SHA1Sum::Hash *aHash, uint32_t *aCnt);
// Checks if a cache entry is currently forced valid. Used to prevent an entry
// (that has been forced valid) from being evicted when the cache size reaches
// its limit.
static bool IsForcedValidEntry(const SHA1Sum::Hash *aHash);
// Returns cache size in kB.
static nsresult GetCacheSize(uint32_t *_retval);
// Synchronously returns the disk occupation and number of entries per-context.
// Callable on any thread.
static nsresult GetCacheStats(nsILoadContextInfo *aInfo, uint32_t *aSize, uint32_t *aCount);
// Asynchronously gets the disk cache size, used for display in the UI.
static nsresult AsyncGetDiskConsumption(nsICacheStorageConsumptionObserver* aObserver);
// Returns an iterator that returns entries matching a given context that were
// present in the index at the time this method was called. If aAddNew is true
// then the iterator will also return entries created after this call.
// NOTE: When some entry is removed from index it is removed also from the
// iterator regardless what aAddNew was passed.
static nsresult GetIterator(nsILoadContextInfo *aInfo, bool aAddNew,
CacheIndexIterator **_retval);
// Returns true if we _think_ that the index is up to date. I.e. the state is
// READY or WRITING and mIndexNeedsUpdate as well as mShuttingDown is false.
static nsresult IsUpToDate(bool *_retval);
// Memory reporting
static size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf);
static size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf);
private:
friend class CacheIndexEntryAutoManage;
friend class CacheIndexAutoLock;
friend class CacheIndexAutoUnlock;
friend class FileOpenHelper;
friend class CacheIndexIterator;
virtual ~CacheIndex();
NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult);
nsresult OnFileOpenedInternal(FileOpenHelper *aOpener,
CacheFileHandle *aHandle, nsresult aResult);
NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
nsresult aResult);
NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult);
NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult);
NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult);
NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult);
void Lock();
void Unlock();
void AssertOwnsLock();
nsresult InitInternal(nsIFile *aCacheDirectory);
void PreShutdownInternal();
// This method returns false when index is not initialized or is shut down.
bool IsIndexUsable();
// This method checks whether the entry has the same values of appId,
// isAnonymous and isInBrowser. We don't expect to find a collision since
// these values are part of the key that we hash and we use a strong hash
// function.
static bool IsCollision(CacheIndexEntry *aEntry,
uint32_t aAppId,
bool aAnonymous,
bool aInBrowser);
// Checks whether any of the information about the entry has changed.
static bool HasEntryChanged(CacheIndexEntry *aEntry,
const uint32_t *aFrecency,
const uint32_t *aExpirationTime,
const uint32_t *aSize);
// Merge all pending operations from mPendingUpdates into mIndex.
void ProcessPendingOperations();
static PLDHashOperator UpdateEntryInIndex(CacheIndexEntry *aEntry,
void* aClosure);
// Following methods perform writing of the index file.
//
// The index is written periodically, but not earlier than once in
// kMinDumpInterval and there must be at least kMinUnwrittenChanges
// differences between index on disk and in memory. Index is always first
// written to a temporary file and the old index file is replaced when the
// writing process succeeds.
//
// Starts writing of index when both limits (minimal delay between writes and
// minimum number of changes in index) were exceeded.
bool WriteIndexToDiskIfNeeded();
// Starts writing of index file.
void WriteIndexToDisk();
// Serializes part of mIndex hashtable to the write buffer a writes the buffer
// to the file.
void WriteRecords();
// Finalizes writing process.
void FinishWrite(bool aSucceeded);
static PLDHashOperator CopyRecordsToRWBuf(CacheIndexEntry *aEntry,
void* aClosure);
static PLDHashOperator ApplyIndexChanges(CacheIndexEntry *aEntry,
void* aClosure);
// Following methods perform writing of the journal during shutdown. All these
// methods must be called only during shutdown since they write/delete files
// directly on the main thread instead of using CacheFileIOManager that does
// it asynchronously on IO thread. Journal contains only entries that are
// dirty, i.e. changes that are not present in the index file on the disk.
// When the log is written successfully, the dirty flag in index file is
// cleared.
nsresult GetFile(const nsACString &aName, nsIFile **_retval);
nsresult RemoveFile(const nsACString &aName);
void RemoveIndexFromDisk();
// Writes journal to the disk and clears dirty flag in index header.
nsresult WriteLogToDisk();
static PLDHashOperator WriteEntryToLog(CacheIndexEntry *aEntry,
void* aClosure);
// Following methods perform reading of the index from the disk.
//
// Index is read at startup just after initializing the CacheIndex. There are
// 3 files used when manipulating with index: index file, journal file and
// a temporary file. All files contain the hash of the data, so we can check
// whether the content is valid and complete. Index file contains also a dirty
// flag in the index header which is unset on a clean shutdown. During opening
// and reading of the files we determine the status of the whole index from
// the states of the separate files. Following table shows all possible
// combinations:
//
// index, journal, tmpfile
// M * * - index is missing -> BUILD
// I * * - index is invalid -> BUILD
// D * * - index is dirty -> UPDATE
// C M * - index is dirty -> UPDATE
// C I * - unexpected state -> UPDATE
// C V E - unexpected state -> UPDATE
// C V M - index is up to date -> READY
//
// where the letters mean:
// * - any state
// E - file exists
// M - file is missing
// I - data is invalid (parsing failed or hash didn't match)
// D - dirty (data in index file is correct, but dirty flag is set)
// C - clean (index file is clean)
// V - valid (data in journal file is correct)
//
// Note: We accept the data from journal only when the index is up to date as
// a whole (i.e. C,V,M state).
//
// We rename the journal file to the temporary file as soon as possible after
// initial test to ensure that we start update process on the next startup if
// FF crashes during parsing of the index.
//
// Initiates reading index from disk.
void ReadIndexFromDisk();
// Starts reading data from index file.
void StartReadingIndex();
// Parses data read from index file.
void ParseRecords();
// Starts reading data from journal file.
void StartReadingJournal();
// Parses data read from journal file.
void ParseJournal();
// Merges entries from journal into mIndex.
void MergeJournal();
// In debug build this method checks that we have no fresh entry in mIndex
// after we finish reading index and before we process pending operations.
void EnsureNoFreshEntry();
// In debug build this method is called after processing pending operations
// to make sure mIndexStats contains correct information.
void EnsureCorrectStats();
static PLDHashOperator SumIndexStats(CacheIndexEntry *aEntry, void* aClosure);
// Finalizes reading process.
void FinishRead(bool aSucceeded);
static PLDHashOperator ProcessJournalEntry(CacheIndexEntry *aEntry,
void* aClosure);
// Following methods perform updating and building of the index.
// Timer callback that starts update or build process.
static void DelayedUpdate(nsITimer *aTimer, void *aClosure);
// Posts timer event that start update or build process.
nsresult ScheduleUpdateTimer(uint32_t aDelay);
nsresult SetupDirectoryEnumerator();
void InitEntryFromDiskData(CacheIndexEntry *aEntry,
CacheFileMetadata *aMetaData,
int64_t aFileSize);
// Returns true when either a timer is scheduled or event is posted.
bool IsUpdatePending();
// Iterates through all files in entries directory that we didn't create/open
// during this session, parses them and adds the entries to the index.
void BuildIndex();
bool StartUpdatingIndexIfNeeded(bool aSwitchingToReadyState = false);
// Starts update or build process or fires a timer when it is too early after
// startup.
void StartUpdatingIndex(bool aRebuild);
// Iterates through all files in entries directory that we didn't create/open
// during this session and theirs last modified time is newer than timestamp
// in the index header. Parses the files and adds the entries to the index.
void UpdateIndex();
// Finalizes update or build process.
void FinishUpdate(bool aSucceeded);
static PLDHashOperator RemoveNonFreshEntries(CacheIndexEntry *aEntry,
void* aClosure);
enum EState {
// Initial state in which the index is not usable
// Possible transitions:
// -> READING
INITIAL = 0,
// Index is being read from the disk.
// Possible transitions:
// -> INITIAL - We failed to dispatch a read event.
// -> BUILDING - No or corrupted index file was found.
// -> UPDATING - No or corrupted journal file was found.
// - Dirty flag was set in index header.
// -> READY - Index was read successfully or was interrupted by
// pre-shutdown.
// -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
READING = 1,
// Index is being written to the disk.
// Possible transitions:
// -> READY - Writing of index finished or was interrupted by
// pre-shutdown..
// -> UPDATING - Writing of index finished, but index was found outdated
// during writing.
// -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
WRITING = 2,
// Index is being build.
// Possible transitions:
// -> READY - Building of index finished or was interrupted by
// pre-shutdown.
// -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
BUILDING = 3,
// Index is being updated.
// Possible transitions:
// -> READY - Updating of index finished or was interrupted by
// pre-shutdown.
// -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
UPDATING = 4,
// Index is ready.
// Possible transitions:
// -> UPDATING - Index was found outdated.
// -> SHUTDOWN - Index is shutting down.
READY = 5,
// Index is shutting down.
SHUTDOWN = 6
};
#ifdef PR_LOGGING
static char const * StateString(EState aState);
#endif
void ChangeState(EState aNewState);
// Allocates and releases buffer used for reading and writing index.
void AllocBuffer();
void ReleaseBuffer();
// Methods used by CacheIndexEntryAutoManage to keep the arrays up to date.
void InsertRecordToFrecencyArray(CacheIndexRecord *aRecord);
void InsertRecordToExpirationArray(CacheIndexRecord *aRecord);
void RemoveRecordFromFrecencyArray(CacheIndexRecord *aRecord);
void RemoveRecordFromExpirationArray(CacheIndexRecord *aRecord);
// Methods used by CacheIndexEntryAutoManage to keep the iterators up to date.
void AddRecordToIterators(CacheIndexRecord *aRecord);
void RemoveRecordFromIterators(CacheIndexRecord *aRecord);
void ReplaceRecordInIterators(CacheIndexRecord *aOldRecord,
CacheIndexRecord *aNewRecord);
// Memory reporting (private part)
size_t SizeOfExcludingThisInternal(mozilla::MallocSizeOf mallocSizeOf) const;
static CacheIndex *gInstance;
nsCOMPtr<nsIFile> mCacheDirectory;
mozilla::Mutex mLock;
EState mState;
// Timestamp of time when the index was initialized. We use it to delay
// initial update or build of index.
TimeStamp mStartTime;
// Set to true in PreShutdown(), it is checked on variaous places to prevent
// starting any process (write, update, etc.) during shutdown.
bool mShuttingDown;
// When set to true, update process should start as soon as possible. This
// flag is set whenever we find some inconsistency which would be fixed by
// update process. The flag is checked always when switching to READY state.
// To make sure we start the update process as soon as possible, methods that
// set this flag should also call StartUpdatingIndexIfNeeded() to cover the
// case when we are currently in READY state.
bool mIndexNeedsUpdate;
// Set at the beginning of RemoveAll() which clears the whole index. When
// removing all entries we must stop any pending reading, writing, updating or
// building operation. This flag is checked at various places and it prevents
// we won't start another operation (e.g. canceling reading of the index would
// normally start update or build process)
bool mRemovingAll;
// Whether the index file on disk exists and is valid.
bool mIndexOnDiskIsValid;
// When something goes wrong during updating or building process, we don't
// mark index clean (and also don't write journal) to ensure that update or
// build will be initiated on the next start.
bool mDontMarkIndexClean;
// Timestamp value from index file. It is used during update process to skip
// entries that were last modified before this timestamp.
uint32_t mIndexTimeStamp;
// Timestamp of last time the index was dumped to disk.
// NOTE: The index might not be necessarily dumped at this time. The value
// is used to schedule next dump of the index.
TimeStamp mLastDumpTime;
// Timer of delayed update/build.
nsCOMPtr<nsITimer> mUpdateTimer;
// True when build or update event is posted
bool mUpdateEventPending;
// Helper members used when reading/writing index from/to disk.
// Contains number of entries that should be skipped:
// - in hashtable when writing index because they were already written
// - in index file when reading index because they were already read
uint32_t mSkipEntries;
// Number of entries that should be written to disk. This is number of entries
// in hashtable that are initialized and are not marked as removed when writing
// begins.
uint32_t mProcessEntries;
char *mRWBuf;
uint32_t mRWBufSize;
uint32_t mRWBufPos;
nsRefPtr<CacheHash> mRWHash;
// Reading of journal succeeded if true.
bool mJournalReadSuccessfully;
// Handle used for writing and reading index file.
nsRefPtr<CacheFileHandle> mIndexHandle;
// Handle used for reading journal file.
nsRefPtr<CacheFileHandle> mJournalHandle;
// Used to check the existence of the file during reading process.
nsRefPtr<CacheFileHandle> mTmpHandle;
nsRefPtr<FileOpenHelper> mIndexFileOpener;
nsRefPtr<FileOpenHelper> mJournalFileOpener;
nsRefPtr<FileOpenHelper> mTmpFileOpener;
// Directory enumerator used when building and updating index.
nsCOMPtr<nsIDirectoryEnumerator> mDirEnumerator;
// Main index hashtable.
nsTHashtable<CacheIndexEntry> mIndex;
// We cannot add, remove or change any entry in mIndex in states READING and
// WRITING. We track all changes in mPendingUpdates during these states.
nsTHashtable<CacheIndexEntry> mPendingUpdates;
// Contains information statistics for mIndex + mPendingUpdates.
CacheIndexStats mIndexStats;
// When reading journal, we must first parse the whole file and apply the
// changes iff the journal was read successfully. mTmpJournal is used to store
// entries from the journal file. We throw away all these entries if parsing
// of the journal fails or the hash does not match.
nsTHashtable<CacheIndexEntry> mTmpJournal;
// Arrays that keep entry records ordered by eviction preference. When looking
// for an entry to evict, we first try to find an expired entry. If there is
// no expired entry, we take the entry with lowest valid frecency. Zero
// frecency is an initial value and such entries are stored at the end of the
// array. Uninitialized entries and entries marked as deleted are not present
// in these arrays.
nsTArray<CacheIndexRecord *> mFrecencyArray;
nsTArray<CacheIndexRecord *> mExpirationArray;
nsTArray<CacheIndexIterator *> mIterators;
class DiskConsumptionObserver : public nsRunnable
{
public:
static DiskConsumptionObserver* Init(nsICacheStorageConsumptionObserver* aObserver)
{
nsWeakPtr observer = do_GetWeakReference(aObserver);
if (!observer)
return nullptr;
return new DiskConsumptionObserver(observer);
}
void OnDiskConsumption(int64_t aSize)
{
mSize = aSize;
NS_DispatchToMainThread(this);
}
private:
DiskConsumptionObserver(nsWeakPtr const &aWeakObserver)
: mObserver(aWeakObserver) { }
virtual ~DiskConsumptionObserver() { }
NS_IMETHODIMP Run()
{
MOZ_ASSERT(NS_IsMainThread());
nsCOMPtr<nsICacheStorageConsumptionObserver> observer =
do_QueryReferent(mObserver);
if (observer) {
observer->OnNetworkCacheDiskConsumption(mSize);
}
return NS_OK;
}
nsWeakPtr mObserver;
int64_t mSize;
};
// List of async observers that want to get disk consumption information
nsTArray<nsRefPtr<DiskConsumptionObserver> > mDiskConsumptionObservers;
};
class CacheIndexAutoLock {
public:
CacheIndexAutoLock(CacheIndex *aIndex)
: mIndex(aIndex)
, mLocked(true)
{
mIndex->Lock();
}
~CacheIndexAutoLock()
{
if (mLocked) {
mIndex->Unlock();
}
}
void Lock()
{
MOZ_ASSERT(!mLocked);
mIndex->Lock();
mLocked = true;
}
void Unlock()
{
MOZ_ASSERT(mLocked);
mIndex->Unlock();
mLocked = false;
}
private:
nsRefPtr<CacheIndex> mIndex;
bool mLocked;
};
class CacheIndexAutoUnlock {
public:
CacheIndexAutoUnlock(CacheIndex *aIndex)
: mIndex(aIndex)
, mLocked(false)
{
mIndex->Unlock();
}
~CacheIndexAutoUnlock()
{
if (!mLocked) {
mIndex->Lock();
}
}
void Lock()
{
MOZ_ASSERT(!mLocked);
mIndex->Lock();
mLocked = true;
}
void Unlock()
{
MOZ_ASSERT(mLocked);
mIndex->Unlock();
mLocked = false;
}
private:
nsRefPtr<CacheIndex> mIndex;
bool mLocked;
};
} // net
} // mozilla
#endif
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