pjs/startupcache/StartupCache.cpp

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21 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
/* 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/. */
#include "prio.h"
#include "prtypes.h"
#include "pldhash.h"
#include "nsXPCOMStrings.h"
#include "mozilla/scache/StartupCache.h"
#include "nsAutoPtr.h"
#include "nsClassHashtable.h"
#include "nsComponentManagerUtils.h"
#include "nsDirectoryServiceUtils.h"
#include "nsIClassInfo.h"
#include "nsIFile.h"
#include "nsIMemoryReporter.h"
#include "nsIObserver.h"
#include "nsIObserverService.h"
#include "nsIOutputStream.h"
#include "nsIStartupCache.h"
#include "nsIStorageStream.h"
#include "nsIStreamBufferAccess.h"
#include "nsIStringStream.h"
#include "nsISupports.h"
#include "nsITimer.h"
#include "nsIZipWriter.h"
#include "nsIZipReader.h"
#include "nsWeakReference.h"
#include "nsZipArchive.h"
#include "mozilla/Omnijar.h"
#include "prenv.h"
#include "mozilla/FunctionTimer.h"
#include "mozilla/Telemetry.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
#include "nsIProtocolHandler.h"
#ifdef IS_BIG_ENDIAN
#define SC_ENDIAN "big"
#else
#define SC_ENDIAN "little"
#endif
#if PR_BYTES_PER_WORD == 4
#define SC_WORDSIZE "4"
#else
#define SC_WORDSIZE "8"
#endif
namespace mozilla {
namespace scache {
static PRInt64
GetStartupCacheMappingSize()
{
mozilla::scache::StartupCache* sc = mozilla::scache::StartupCache::GetSingleton();
return sc ? sc->SizeOfMapping() : 0;
}
NS_MEMORY_REPORTER_IMPLEMENT(StartupCacheMapping,
"explicit/startup-cache/mapping",
KIND_NONHEAP,
nsIMemoryReporter::UNITS_BYTES,
GetStartupCacheMappingSize,
"Memory used to hold the mapping of the startup cache from file. This "
"memory is likely to be swapped out shortly after start-up.")
NS_MEMORY_REPORTER_MALLOC_SIZEOF_FUN(StartupCacheDataMallocSizeOf, "startup-cache/data")
static PRInt64
GetStartupCacheDataSize()
{
mozilla::scache::StartupCache* sc = mozilla::scache::StartupCache::GetSingleton();
return sc ? sc->HeapSizeOfIncludingThis(StartupCacheDataMallocSizeOf) : 0;
}
NS_MEMORY_REPORTER_IMPLEMENT(StartupCacheData,
"explicit/startup-cache/data",
KIND_HEAP,
nsIMemoryReporter::UNITS_BYTES,
GetStartupCacheDataSize,
"Memory used by the startup cache for things other than the file mapping.")
static const char sStartupCacheName[] = "startupCache." SC_WORDSIZE "." SC_ENDIAN;
static NS_DEFINE_CID(kZipReaderCID, NS_ZIPREADER_CID);
StartupCache*
StartupCache::GetSingleton()
{
if (!gStartupCache)
StartupCache::InitSingleton();
return StartupCache::gStartupCache;
}
void
StartupCache::DeleteSingleton()
{
delete StartupCache::gStartupCache;
}
nsresult
StartupCache::InitSingleton()
{
nsresult rv;
StartupCache::gStartupCache = new StartupCache();
rv = StartupCache::gStartupCache->Init();
if (NS_FAILED(rv)) {
delete StartupCache::gStartupCache;
StartupCache::gStartupCache = nsnull;
}
return rv;
}
StartupCache* StartupCache::gStartupCache;
bool StartupCache::gShutdownInitiated;
enum StartupCache::TelemetrifyAge StartupCache::gPostFlushAgeAction = StartupCache::IGNORE_AGE;
StartupCache::StartupCache()
: mArchive(NULL), mStartupWriteInitiated(false), mWriteThread(NULL),
mMappingMemoryReporter(nsnull), mDataMemoryReporter(nsnull) { }
StartupCache::~StartupCache()
{
if (mTimer) {
mTimer->Cancel();
}
// Generally, the in-memory table should be empty here,
// but an early shutdown means either mTimer didn't run
// or the write thread is still running.
WaitOnWriteThread();
WriteToDisk();
gStartupCache = nsnull;
(void)::NS_UnregisterMemoryReporter(mMappingMemoryReporter);
(void)::NS_UnregisterMemoryReporter(mDataMemoryReporter);
mMappingMemoryReporter = nsnull;
mDataMemoryReporter = nsnull;
}
nsresult
StartupCache::Init()
{
if (XRE_GetProcessType() != GeckoProcessType_Default) {
NS_WARNING("Startup cache is only available in the chrome process");
return NS_ERROR_NOT_AVAILABLE;
}
// workaround for bug 653936
nsCOMPtr<nsIProtocolHandler> jarInitializer(do_GetService(NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX "jar"));
nsresult rv;
mTable.Init();
#ifdef DEBUG
mWriteObjectMap.Init();
#endif
// This allows to override the startup cache filename
// which is useful from xpcshell, when there is no ProfLDS directory to keep cache in.
char *env = PR_GetEnv("MOZ_STARTUP_CACHE");
if (env) {
rv = NS_NewLocalFile(NS_ConvertUTF8toUTF16(env), false, getter_AddRefs(mFile));
} else {
nsCOMPtr<nsIFile> file;
rv = NS_GetSpecialDirectory("ProfLDS",
getter_AddRefs(file));
if (NS_FAILED(rv)) {
// return silently, this will fail in mochitests's xpcshell process.
return rv;
}
rv = file->AppendNative(NS_LITERAL_CSTRING("startupCache"));
NS_ENSURE_SUCCESS(rv, rv);
// Try to create the directory if it's not there yet
rv = file->Create(nsIFile::DIRECTORY_TYPE, 0777);
if (NS_FAILED(rv) && rv != NS_ERROR_FILE_ALREADY_EXISTS)
return rv;
rv = file->AppendNative(NS_LITERAL_CSTRING(sStartupCacheName));
NS_ENSURE_SUCCESS(rv, rv);
mFile = do_QueryInterface(file);
}
NS_ENSURE_TRUE(mFile, NS_ERROR_UNEXPECTED);
mObserverService = do_GetService("@mozilla.org/observer-service;1");
if (!mObserverService) {
NS_WARNING("Could not get observerService.");
return NS_ERROR_UNEXPECTED;
}
mListener = new StartupCacheListener();
rv = mObserverService->AddObserver(mListener, NS_XPCOM_SHUTDOWN_OBSERVER_ID,
false);
NS_ENSURE_SUCCESS(rv, rv);
rv = mObserverService->AddObserver(mListener, "startupcache-invalidate",
false);
NS_ENSURE_SUCCESS(rv, rv);
rv = LoadArchive(RECORD_AGE);
// Sometimes we don't have a cache yet, that's ok.
// If it's corrupted, just remove it and start over.
if (NS_FAILED(rv) && rv != NS_ERROR_FILE_NOT_FOUND) {
NS_WARNING("Failed to load startupcache file correctly, removing!");
InvalidateCache();
}
mMappingMemoryReporter = new NS_MEMORY_REPORTER_NAME(StartupCacheMapping);
mDataMemoryReporter = new NS_MEMORY_REPORTER_NAME(StartupCacheData);
(void)::NS_RegisterMemoryReporter(mMappingMemoryReporter);
(void)::NS_RegisterMemoryReporter(mDataMemoryReporter);
return NS_OK;
}
/**
* LoadArchive can be called from the main thread or while reloading cache on write thread.
*/
nsresult
StartupCache::LoadArchive(enum TelemetrifyAge flag)
{
bool exists;
mArchive = NULL;
nsresult rv = mFile->Exists(&exists);
if (NS_FAILED(rv) || !exists)
return NS_ERROR_FILE_NOT_FOUND;
mArchive = new nsZipArchive();
rv = mArchive->OpenArchive(mFile);
if (NS_FAILED(rv) || flag == IGNORE_AGE)
return rv;
nsCString comment;
if (!mArchive->GetComment(comment)) {
return rv;
}
const char *data;
size_t len = NS_CStringGetData(comment, &data);
PRTime creationStamp;
// We might not have a comment if the startup cache file was created
// before we started recording creation times in the comment.
if (len == sizeof(creationStamp)) {
memcpy(&creationStamp, data, len);
PRTime current = PR_Now();
PRInt64 diff = current - creationStamp;
// We can't use AccumulateTimeDelta here because we have no way of
// reifying a TimeStamp from creationStamp.
PRInt64 usec_per_hour = PR_USEC_PER_SEC * PRInt64(3600);
PRInt64 hour_diff = (diff + usec_per_hour - 1) / usec_per_hour;
mozilla::Telemetry::Accumulate(Telemetry::STARTUP_CACHE_AGE_HOURS,
hour_diff);
}
return rv;
}
namespace {
nsresult
GetBufferFromZipArchive(nsZipArchive *zip, bool doCRC, const char* id,
char** outbuf, PRUint32* length)
{
if (!zip)
return NS_ERROR_NOT_AVAILABLE;
nsZipItemPtr<char> zipItem(zip, id, doCRC);
if (!zipItem)
return NS_ERROR_NOT_AVAILABLE;
*outbuf = zipItem.Forget();
*length = zipItem.Length();
return NS_OK;
}
} /* anonymous namespace */
// NOTE: this will not find a new entry until it has been written to disk!
// Consumer should take ownership of the resulting buffer.
nsresult
StartupCache::GetBuffer(const char* id, char** outbuf, PRUint32* length)
{
NS_ASSERTION(NS_IsMainThread(), "Startup cache only available on main thread");
WaitOnWriteThread();
if (!mStartupWriteInitiated) {
CacheEntry* entry;
nsDependentCString idStr(id);
mTable.Get(idStr, &entry);
if (entry) {
*outbuf = new char[entry->size];
memcpy(*outbuf, entry->data, entry->size);
*length = entry->size;
return NS_OK;
}
}
nsresult rv = GetBufferFromZipArchive(mArchive, true, id, outbuf, length);
if (NS_SUCCEEDED(rv))
return rv;
nsRefPtr<nsZipArchive> omnijar = mozilla::Omnijar::GetReader(mozilla::Omnijar::APP);
// no need to checksum omnijarred entries
rv = GetBufferFromZipArchive(omnijar, false, id, outbuf, length);
if (NS_SUCCEEDED(rv))
return rv;
omnijar = mozilla::Omnijar::GetReader(mozilla::Omnijar::GRE);
// no need to checksum omnijarred entries
return GetBufferFromZipArchive(omnijar, false, id, outbuf, length);
}
// Makes a copy of the buffer, client retains ownership of inbuf.
nsresult
StartupCache::PutBuffer(const char* id, const char* inbuf, PRUint32 len)
{
NS_ASSERTION(NS_IsMainThread(), "Startup cache only available on main thread");
WaitOnWriteThread();
if (StartupCache::gShutdownInitiated) {
return NS_ERROR_NOT_AVAILABLE;
}
nsAutoArrayPtr<char> data(new char[len]);
memcpy(data, inbuf, len);
nsDependentCString idStr(id);
// Cache it for now, we'll write all together later.
CacheEntry* entry;
#ifdef DEBUG
mTable.Get(idStr, &entry);
NS_ASSERTION(entry == nsnull, "Existing entry in StartupCache.");
if (mArchive) {
nsZipItem* zipItem = mArchive->GetItem(id);
NS_ASSERTION(zipItem == nsnull, "Existing entry in disk StartupCache.");
}
#endif
entry = new CacheEntry(data.forget(), len);
mTable.Put(idStr, entry);
return ResetStartupWriteTimer();
}
size_t
StartupCache::SizeOfMapping()
{
return mArchive ? mArchive->SizeOfMapping() : 0;
}
size_t
StartupCache::HeapSizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf)
{
// This function could measure more members, but they haven't been found by
// DMD to be significant. They can be added later if necessary.
return aMallocSizeOf(this) +
mTable.SizeOfExcludingThis(SizeOfEntryExcludingThis, aMallocSizeOf);
}
/* static */ size_t
StartupCache::SizeOfEntryExcludingThis(const nsACString& key, const nsAutoPtr<CacheEntry>& data,
nsMallocSizeOfFun mallocSizeOf, void *)
{
return data->SizeOfExcludingThis(mallocSizeOf);
}
struct CacheWriteHolder
{
nsCOMPtr<nsIZipWriter> writer;
nsCOMPtr<nsIStringInputStream> stream;
PRTime time;
};
PLDHashOperator
CacheCloseHelper(const nsACString& key, nsAutoPtr<CacheEntry>& data,
void* closure)
{
nsresult rv;
CacheWriteHolder* holder = (CacheWriteHolder*) closure;
nsIStringInputStream* stream = holder->stream;
nsIZipWriter* writer = holder->writer;
stream->ShareData(data->data, data->size);
#ifdef DEBUG
bool hasEntry;
rv = writer->HasEntry(key, &hasEntry);
NS_ASSERTION(NS_SUCCEEDED(rv) && hasEntry == false,
"Existing entry in disk StartupCache.");
#endif
rv = writer->AddEntryStream(key, holder->time, true, stream, false);
if (NS_FAILED(rv)) {
NS_WARNING("cache entry deleted but not written to disk.");
}
return PL_DHASH_REMOVE;
}
/**
* WriteToDisk writes the cache out to disk. Callers of WriteToDisk need to call WaitOnWriteThread
* to make sure there isn't a write happening on another thread
*/
void
StartupCache::WriteToDisk()
{
nsresult rv;
mStartupWriteInitiated = true;
if (mTable.Count() == 0)
return;
nsCOMPtr<nsIZipWriter> zipW = do_CreateInstance("@mozilla.org/zipwriter;1");
if (!zipW)
return;
rv = zipW->Open(mFile, PR_RDWR | PR_CREATE_FILE);
if (NS_FAILED(rv)) {
NS_WARNING("could not open zipfile for write");
return;
}
// If we didn't have an mArchive member, that means that we failed to
// open the startup cache for reading. Therefore, we need to record
// the time of creation in a zipfile comment; this will be useful for
// Telemetry statistics.
PRTime now = PR_Now();
if (!mArchive) {
nsCString comment;
comment.Assign((char *)&now, sizeof(now));
zipW->SetComment(comment);
}
nsCOMPtr<nsIStringInputStream> stream
= do_CreateInstance("@mozilla.org/io/string-input-stream;1", &rv);
if (NS_FAILED(rv)) {
NS_WARNING("Couldn't create string input stream.");
return;
}
CacheWriteHolder holder;
holder.stream = stream;
holder.writer = zipW;
holder.time = now;
mTable.Enumerate(CacheCloseHelper, &holder);
// Close the archive so Windows doesn't choke.
mArchive = NULL;
zipW->Close();
// Our reader's view of the archive is outdated now, reload it.
LoadArchive(gPostFlushAgeAction);
return;
}
void
StartupCache::InvalidateCache()
{
WaitOnWriteThread();
mTable.Clear();
mArchive = NULL;
mFile->Remove(false);
LoadArchive(gPostFlushAgeAction);
}
/*
* WaitOnWriteThread() is called from a main thread to wait for the worker
* thread to finish. However since the same code is used in the worker thread and
* main thread, the worker thread can also call WaitOnWriteThread() which is a no-op.
*/
void
StartupCache::WaitOnWriteThread()
{
NS_ASSERTION(NS_IsMainThread(), "Startup cache should only wait for io thread on main thread");
if (!mWriteThread || mWriteThread == PR_GetCurrentThread())
return;
NS_TIME_FUNCTION_MIN(30);
PR_JoinThread(mWriteThread);
mWriteThread = NULL;
}
void
StartupCache::ThreadedWrite(void *aClosure)
{
PR_SetCurrentThreadName("StartupCache");
gStartupCache->WriteToDisk();
}
/*
* The write-thread is spawned on a timeout(which is reset with every write). This
* can avoid a slow shutdown. After writing out the cache, the zipreader is
* reloaded on the worker thread.
*/
void
StartupCache::WriteTimeout(nsITimer *aTimer, void *aClosure)
{
gStartupCache->mWriteThread = PR_CreateThread(PR_USER_THREAD,
StartupCache::ThreadedWrite,
NULL,
PR_PRIORITY_NORMAL,
PR_LOCAL_THREAD,
PR_JOINABLE_THREAD,
0);
}
// We don't want to refcount StartupCache, so we'll just
// hold a ref to this and pass it to observerService instead.
NS_IMPL_THREADSAFE_ISUPPORTS1(StartupCacheListener, nsIObserver)
nsresult
StartupCacheListener::Observe(nsISupports *subject, const char* topic, const PRUnichar* data)
{
StartupCache* sc = StartupCache::GetSingleton();
if (!sc)
return NS_OK;
if (strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
// Do not leave the thread running past xpcom shutdown
sc->WaitOnWriteThread();
StartupCache::gShutdownInitiated = true;
} else if (strcmp(topic, "startupcache-invalidate") == 0) {
sc->InvalidateCache();
}
return NS_OK;
}
nsresult
StartupCache::GetDebugObjectOutputStream(nsIObjectOutputStream* aStream,
nsIObjectOutputStream** aOutStream)
{
NS_ENSURE_ARG_POINTER(aStream);
#ifdef DEBUG
StartupCacheDebugOutputStream* stream
= new StartupCacheDebugOutputStream(aStream, &mWriteObjectMap);
NS_ADDREF(*aOutStream = stream);
#else
NS_ADDREF(*aOutStream = aStream);
#endif
return NS_OK;
}
nsresult
StartupCache::ResetStartupWriteTimer()
{
mStartupWriteInitiated = false;
nsresult rv;
if (!mTimer)
mTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
else
rv = mTimer->Cancel();
NS_ENSURE_SUCCESS(rv, rv);
// Wait for 10 seconds, then write out the cache.
mTimer->InitWithFuncCallback(StartupCache::WriteTimeout, this, 60000,
nsITimer::TYPE_ONE_SHOT);
return NS_OK;
}
nsresult
StartupCache::RecordAgesAlways()
{
gPostFlushAgeAction = RECORD_AGE;
return NS_OK;
}
// StartupCacheDebugOutputStream implementation
#ifdef DEBUG
NS_IMPL_ISUPPORTS3(StartupCacheDebugOutputStream, nsIObjectOutputStream,
nsIBinaryOutputStream, nsIOutputStream)
bool
StartupCacheDebugOutputStream::CheckReferences(nsISupports* aObject)
{
nsresult rv;
nsCOMPtr<nsIClassInfo> classInfo = do_QueryInterface(aObject);
if (!classInfo) {
NS_ERROR("aObject must implement nsIClassInfo");
return false;
}
PRUint32 flags;
rv = classInfo->GetFlags(&flags);
NS_ENSURE_SUCCESS(rv, false);
if (flags & nsIClassInfo::SINGLETON)
return true;
nsISupportsHashKey* key = mObjectMap->GetEntry(aObject);
if (key) {
NS_ERROR("non-singleton aObject is referenced multiple times in this"
"serialization, we don't support that.");
return false;
}
mObjectMap->PutEntry(aObject);
return true;
}
// nsIObjectOutputStream implementation
nsresult
StartupCacheDebugOutputStream::WriteObject(nsISupports* aObject, bool aIsStrongRef)
{
nsCOMPtr<nsISupports> rootObject(do_QueryInterface(aObject));
NS_ASSERTION(rootObject.get() == aObject,
"bad call to WriteObject -- call WriteCompoundObject!");
bool check = CheckReferences(aObject);
NS_ENSURE_TRUE(check, NS_ERROR_FAILURE);
return mBinaryStream->WriteObject(aObject, aIsStrongRef);
}
nsresult
StartupCacheDebugOutputStream::WriteSingleRefObject(nsISupports* aObject)
{
nsCOMPtr<nsISupports> rootObject(do_QueryInterface(aObject));
NS_ASSERTION(rootObject.get() == aObject,
"bad call to WriteSingleRefObject -- call WriteCompoundObject!");
bool check = CheckReferences(aObject);
NS_ENSURE_TRUE(check, NS_ERROR_FAILURE);
return mBinaryStream->WriteSingleRefObject(aObject);
}
nsresult
StartupCacheDebugOutputStream::WriteCompoundObject(nsISupports* aObject,
const nsIID& aIID,
bool aIsStrongRef)
{
nsCOMPtr<nsISupports> rootObject(do_QueryInterface(aObject));
nsCOMPtr<nsISupports> roundtrip;
rootObject->QueryInterface(aIID, getter_AddRefs(roundtrip));
NS_ASSERTION(roundtrip.get() == aObject,
"bad aggregation or multiple inheritance detected by call to "
"WriteCompoundObject!");
bool check = CheckReferences(aObject);
NS_ENSURE_TRUE(check, NS_ERROR_FAILURE);
return mBinaryStream->WriteCompoundObject(aObject, aIID, aIsStrongRef);
}
nsresult
StartupCacheDebugOutputStream::WriteID(nsID const& aID)
{
return mBinaryStream->WriteID(aID);
}
char*
StartupCacheDebugOutputStream::GetBuffer(PRUint32 aLength, PRUint32 aAlignMask)
{
return mBinaryStream->GetBuffer(aLength, aAlignMask);
}
void
StartupCacheDebugOutputStream::PutBuffer(char* aBuffer, PRUint32 aLength)
{
mBinaryStream->PutBuffer(aBuffer, aLength);
}
#endif //DEBUG
StartupCacheWrapper* StartupCacheWrapper::gStartupCacheWrapper = nsnull;
NS_IMPL_THREADSAFE_ISUPPORTS1(StartupCacheWrapper, nsIStartupCache)
StartupCacheWrapper* StartupCacheWrapper::GetSingleton()
{
if (!gStartupCacheWrapper)
gStartupCacheWrapper = new StartupCacheWrapper();
NS_ADDREF(gStartupCacheWrapper);
return gStartupCacheWrapper;
}
nsresult
StartupCacheWrapper::GetBuffer(const char* id, char** outbuf, PRUint32* length)
{
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
return sc->GetBuffer(id, outbuf, length);
}
nsresult
StartupCacheWrapper::PutBuffer(const char* id, const char* inbuf, PRUint32 length)
{
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
return sc->PutBuffer(id, inbuf, length);
}
nsresult
StartupCacheWrapper::InvalidateCache()
{
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
sc->InvalidateCache();
return NS_OK;
}
nsresult
StartupCacheWrapper::GetDebugObjectOutputStream(nsIObjectOutputStream* stream,
nsIObjectOutputStream** outStream)
{
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
return sc->GetDebugObjectOutputStream(stream, outStream);
}
nsresult
StartupCacheWrapper::StartupWriteComplete(bool *complete)
{
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
sc->WaitOnWriteThread();
*complete = sc->mStartupWriteInitiated && sc->mTable.Count() == 0;
return NS_OK;
}
nsresult
StartupCacheWrapper::ResetStartupWriteTimer()
{
StartupCache* sc = StartupCache::GetSingleton();
return sc ? sc->ResetStartupWriteTimer() : NS_ERROR_NOT_INITIALIZED;
}
nsresult
StartupCacheWrapper::GetObserver(nsIObserver** obv) {
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
NS_ADDREF(*obv = sc->mListener);
return NS_OK;
}
nsresult
StartupCacheWrapper::RecordAgesAlways() {
StartupCache *sc = StartupCache::GetSingleton();
return sc ? sc->RecordAgesAlways() : NS_ERROR_NOT_INITIALIZED;
}
} // namespace scache
} // namespace mozilla