gecko-dev/startupcache/StartupCache.cpp

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21 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "PLDHashTable.h"
#include "nsXPCOMStrings.h"
#include "mozilla/IOInterposer.h"
#include "mozilla/MemoryReporting.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 "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/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 {
MOZ_DEFINE_MALLOC_SIZE_OF(StartupCacheMallocSizeOf)
NS_IMETHODIMP
StartupCache::CollectReports(nsIHandleReportCallback* aHandleReport,
nsISupports* aData, bool aAnonymize)
{
MOZ_COLLECT_REPORT(
"explicit/startup-cache/mapping", KIND_NONHEAP, UNITS_BYTES,
SizeOfMapping(),
"Memory used to hold the mapping of the startup cache from file. "
"This memory is likely to be swapped out shortly after start-up.");
MOZ_COLLECT_REPORT(
"explicit/startup-cache/data", KIND_HEAP, UNITS_BYTES,
HeapSizeOfIncludingThis(StartupCacheMallocSizeOf),
"Memory used by the startup cache for things other than the file mapping.");
return NS_OK;
}
#define STARTUP_CACHE_NAME "startupCache." SC_WORDSIZE "." SC_ENDIAN
StartupCache*
StartupCache::GetSingleton()
{
if (!gStartupCache) {
if (!XRE_IsParentProcess()) {
return nullptr;
}
#ifdef MOZ_DISABLE_STARTUPCACHE
return nullptr;
#else
StartupCache::InitSingleton();
#endif
}
return StartupCache::gStartupCache;
}
void
StartupCache::DeleteSingleton()
{
StartupCache::gStartupCache = nullptr;
}
nsresult
StartupCache::InitSingleton()
{
nsresult rv;
StartupCache::gStartupCache = new StartupCache();
rv = StartupCache::gStartupCache->Init();
if (NS_FAILED(rv)) {
StartupCache::gStartupCache = nullptr;
}
return rv;
}
StaticRefPtr<StartupCache> StartupCache::gStartupCache;
bool StartupCache::gShutdownInitiated;
bool StartupCache::gIgnoreDiskCache;
NS_IMPL_ISUPPORTS(StartupCache, nsIMemoryReporter)
StartupCache::StartupCache()
: mArchive(nullptr), mStartupWriteInitiated(false), mWriteThread(nullptr)
{ }
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();
// If we shutdown quickly timer wont have fired. Instead of writing
// it on the main thread and block the shutdown we simply wont update
// the startup cache. Always do this if the file doesn't exist since
// we use it part of the package step.
if (!mArchive) {
WriteToDisk();
}
UnregisterWeakMemoryReporter(this);
}
nsresult
StartupCache::Init()
{
// workaround for bug 653936
nsCOMPtr<nsIProtocolHandler> jarInitializer(do_GetService(NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX "jar"));
nsresult rv;
// 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 && *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;
}
nsCOMPtr<nsIFile> profDir;
NS_GetSpecialDirectory("ProfDS", getter_AddRefs(profDir));
if (profDir) {
bool same;
if (NS_SUCCEEDED(profDir->Equals(file, &same)) && !same) {
// We no longer store the startup cache in the main profile
// directory, so we should cleanup the old one.
if (NS_SUCCEEDED(
profDir->AppendNative(NS_LITERAL_CSTRING("startupCache")))) {
profDir->Remove(true);
}
}
}
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(STARTUP_CACHE_NAME));
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();
// Sometimes we don't have a cache yet, that's ok.
// If it's corrupted, just remove it and start over.
if (gIgnoreDiskCache || (NS_FAILED(rv) && rv != NS_ERROR_FILE_NOT_FOUND)) {
NS_WARNING("Failed to load startupcache file correctly, removing!");
InvalidateCache();
}
RegisterWeakMemoryReporter(this);
return NS_OK;
}
/**
* LoadArchive can be called from the main thread or while reloading cache on write thread.
*/
nsresult
StartupCache::LoadArchive()
{
if (gIgnoreDiskCache)
return NS_ERROR_FAILURE;
bool exists;
mArchive = nullptr;
nsresult rv = mFile->Exists(&exists);
if (NS_FAILED(rv) || !exists)
return NS_ERROR_FILE_NOT_FOUND;
mArchive = new nsZipArchive();
rv = mArchive->OpenArchive(mFile);
return rv;
}
namespace {
nsresult
GetBufferFromZipArchive(nsZipArchive *zip, bool doCRC, const char* id,
UniquePtr<char[]>* outbuf, uint32_t* 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, UniquePtr<char[]>* outbuf, uint32_t* length)
{
PROFILER_LABEL_FUNC(js::ProfileEntry::Category::OTHER);
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 = MakeUnique<char[]>(entry->size);
memcpy(outbuf->get(), entry->data.get(), entry->size);
*length = entry->size;
return NS_OK;
}
}
nsresult rv = GetBufferFromZipArchive(mArchive, true, id, outbuf, length);
if (NS_SUCCEEDED(rv))
return rv;
RefPtr<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, uint32_t len)
{
NS_ASSERTION(NS_IsMainThread(), "Startup cache only available on main thread");
WaitOnWriteThread();
if (StartupCache::gShutdownInitiated) {
return NS_ERROR_NOT_AVAILABLE;
}
auto data = MakeUnique<char[]>(len);
memcpy(data.get(), inbuf, len);
nsCString idStr(id);
// Cache it for now, we'll write all together later.
CacheEntry* entry;
if (mTable.Get(idStr)) {
NS_WARNING("Existing entry in StartupCache.");
// Double-caching is undesirable but not an error.
return NS_OK;
}
#ifdef DEBUG
if (mArchive) {
nsZipItem* zipItem = mArchive->GetItem(id);
NS_ASSERTION(zipItem == nullptr, "Existing entry in disk StartupCache.");
}
#endif
entry = new CacheEntry(Move(data), len);
mTable.Put(idStr, entry);
mPendingWrites.AppendElement(idStr);
return ResetStartupWriteTimer();
}
size_t
StartupCache::SizeOfMapping()
{
return mArchive ? mArchive->SizeOfMapping() : 0;
}
size_t
StartupCache::HeapSizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
{
// This function could measure more members, but they haven't been found by
// DMD to be significant. They can be added later if necessary.
size_t n = aMallocSizeOf(this);
n += mTable.ShallowSizeOfExcludingThis(aMallocSizeOf);
for (auto iter = mTable.ConstIter(); !iter.Done(); iter.Next()) {
n += iter.Data()->SizeOfIncludingThis(aMallocSizeOf);
}
n += mPendingWrites.ShallowSizeOfExcludingThis(aMallocSizeOf);
return n;
}
struct CacheWriteHolder
{
nsCOMPtr<nsIZipWriter> writer;
nsCOMPtr<nsIStringInputStream> stream;
PRTime time;
};
static void
CacheCloseHelper(const nsACString& key, const CacheEntry* data,
const CacheWriteHolder* holder)
{
MOZ_ASSERT(data); // assert key was found in mTable.
nsresult rv;
nsIStringInputStream* stream = holder->stream;
nsIZipWriter* writer = holder->writer;
stream->ShareData(data->data.get(), 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.");
}
}
/**
* 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 has been 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;
for (auto& key : mPendingWrites) {
CacheCloseHelper(key, mTable.Get(key), &holder);
}
mPendingWrites.Clear();
mTable.Clear();
// Close the archive so Windows doesn't choke.
mArchive = nullptr;
zipW->Close();
// We succesfully wrote the archive to disk; mark the disk file as trusted
gIgnoreDiskCache = false;
// Our reader's view of the archive is outdated now, reload it.
LoadArchive();
return;
}
void
StartupCache::InvalidateCache()
{
WaitOnWriteThread();
mPendingWrites.Clear();
mTable.Clear();
mArchive = nullptr;
nsresult rv = mFile->Remove(false);
if (NS_FAILED(rv) && rv != NS_ERROR_FILE_TARGET_DOES_NOT_EXIST &&
rv != NS_ERROR_FILE_NOT_FOUND) {
gIgnoreDiskCache = true;
return;
}
gIgnoreDiskCache = false;
LoadArchive();
}
void
StartupCache::IgnoreDiskCache()
{
gIgnoreDiskCache = true;
if (gStartupCache)
gStartupCache->InvalidateCache();
}
/*
* 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;
PR_JoinThread(mWriteThread);
mWriteThread = nullptr;
}
void
StartupCache::ThreadedWrite(void *aClosure)
{
PR_SetCurrentThreadName("StartupCache");
mozilla::IOInterposer::RegisterCurrentThread();
/*
* It is safe to use the pointer passed in aClosure to reference the
* StartupCache object because the thread's lifetime is tightly coupled to
* the lifetime of the StartupCache object; this thread is joined in the
* StartupCache destructor, guaranteeing that this function runs if and only
* if the StartupCache object is valid.
*/
StartupCache* startupCacheObj = static_cast<StartupCache*>(aClosure);
startupCacheObj->WriteToDisk();
mozilla::IOInterposer::UnregisterCurrentThread();
}
/*
* 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)
{
/*
* It is safe to use the pointer passed in aClosure to reference the
* StartupCache object because the timer's lifetime is tightly coupled to
* the lifetime of the StartupCache object; this timer is canceled in the
* StartupCache destructor, guaranteeing that this function runs if and only
* if the StartupCache object is valid.
*/
StartupCache* startupCacheObj = static_cast<StartupCache*>(aClosure);
startupCacheObj->mWriteThread = PR_CreateThread(PR_USER_THREAD,
StartupCache::ThreadedWrite,
startupCacheObj,
PR_PRIORITY_NORMAL,
PR_GLOBAL_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_ISUPPORTS(StartupCacheListener, nsIObserver)
nsresult
StartupCacheListener::Observe(nsISupports *subject, const char* topic, const char16_t* 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
auto* 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;
}
bool
StartupCache::StartupWriteComplete()
{
WaitOnWriteThread();
return mStartupWriteInitiated && mTable.Count() == 0;
}
// StartupCacheDebugOutputStream implementation
#ifdef DEBUG
NS_IMPL_ISUPPORTS(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;
}
uint32_t 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(uint32_t aLength, uint32_t aAlignMask)
{
return mBinaryStream->GetBuffer(aLength, aAlignMask);
}
void
StartupCacheDebugOutputStream::PutBuffer(char* aBuffer, uint32_t aLength)
{
mBinaryStream->PutBuffer(aBuffer, aLength);
}
#endif //DEBUG
StartupCacheWrapper* StartupCacheWrapper::gStartupCacheWrapper = nullptr;
NS_IMPL_ISUPPORTS(StartupCacheWrapper, nsIStartupCache)
StartupCacheWrapper* StartupCacheWrapper::GetSingleton()
{
if (!gStartupCacheWrapper)
gStartupCacheWrapper = new StartupCacheWrapper();
NS_ADDREF(gStartupCacheWrapper);
return gStartupCacheWrapper;
}
nsresult
StartupCacheWrapper::GetBuffer(const char* id, char** outbuf, uint32_t* length)
{
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
UniquePtr<char[]> buf;
nsresult rv = sc->GetBuffer(id, &buf, length);
*outbuf = buf.release();
return rv;
}
nsresult
StartupCacheWrapper::PutBuffer(const char* id, const char* inbuf, uint32_t 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::GetObserver(nsIObserver** obv) {
StartupCache* sc = StartupCache::GetSingleton();
if (!sc) {
return NS_ERROR_NOT_INITIALIZED;
}
NS_ADDREF(*obv = sc->mListener);
return NS_OK;
}
} // namespace scache
} // namespace mozilla