gecko-dev/dom/file/FileService.cpp

528 lines
14 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=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 "FileService.h"
#include "nsIFile.h"
#include "nsIFileStorage.h"
#include "nsIObserverService.h"
#include "nsIStreamTransportService.h"
#include "nsNetCID.h"
#include "FileHandle.h"
#include "FileRequest.h"
USING_FILE_NAMESPACE
namespace {
FileService* gInstance = nullptr;
bool gShutdown = false;
} // anonymous namespace
FileService::FileService()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(!gInstance, "More than one instance!");
}
FileService::~FileService()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(!gInstance, "More than one instance!");
}
nsresult
FileService::Init()
{
mFileStorageInfos.Init();
nsresult rv;
mStreamTransportTarget =
do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
return rv;
}
nsresult
FileService::Cleanup()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
nsIThread* thread = NS_GetCurrentThread();
while (mFileStorageInfos.Count()) {
if (!NS_ProcessNextEvent(thread)) {
NS_ERROR("Failed to process next event!");
break;
}
}
// Make sure the service is still accessible while any generated callbacks
// are processed.
nsresult rv = NS_ProcessPendingEvents(thread);
NS_ENSURE_SUCCESS(rv, rv);
if (!mCompleteCallbacks.IsEmpty()) {
// Run all callbacks manually now.
for (uint32_t index = 0; index < mCompleteCallbacks.Length(); index++) {
mCompleteCallbacks[index].mCallback->Run();
}
mCompleteCallbacks.Clear();
// And make sure they get processed.
rv = NS_ProcessPendingEvents(thread);
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
// static
FileService*
FileService::GetOrCreate()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
if (gShutdown) {
NS_WARNING("Calling GetOrCreate() after shutdown!");
return nullptr;
}
if (!gInstance) {
nsRefPtr<FileService> service(new FileService);
nsresult rv = service->Init();
NS_ENSURE_SUCCESS(rv, nullptr);
nsCOMPtr<nsIObserverService> obs =
do_GetService(NS_OBSERVERSERVICE_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, nullptr);
rv = obs->AddObserver(service, "profile-before-change", false);
NS_ENSURE_SUCCESS(rv, nullptr);
// The observer service now owns us.
gInstance = service;
}
return gInstance;
}
// static
FileService*
FileService::Get()
{
// Does not return an owning reference.
return gInstance;
}
// static
void
FileService::Shutdown()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
gShutdown = true;
if (gInstance) {
if (NS_FAILED(gInstance->Cleanup())) {
NS_WARNING("Failed to shutdown file service!");
}
gInstance = nullptr;
}
}
// static
bool
FileService::IsShuttingDown()
{
return gShutdown;
}
nsresult
FileService::Enqueue(LockedFile* aLockedFile, FileHelper* aFileHelper)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(aLockedFile, "Null pointer!");
FileHandle* fileHandle = aLockedFile->mFileHandle;
if (fileHandle->mFileStorage->IsInvalidated()) {
return NS_ERROR_NOT_AVAILABLE;
}
nsIAtom* storageId = fileHandle->mFileStorage->Id();
const nsAString& fileName = fileHandle->mFileName;
bool modeIsWrite = aLockedFile->mMode == FileMode::Readwrite;
FileStorageInfo* fileStorageInfo;
if (!mFileStorageInfos.Get(storageId, &fileStorageInfo)) {
nsAutoPtr<FileStorageInfo> newFileStorageInfo(new FileStorageInfo());
mFileStorageInfos.Put(storageId, newFileStorageInfo);
fileStorageInfo = newFileStorageInfo.forget();
}
LockedFileQueue* existingLockedFileQueue =
fileStorageInfo->GetLockedFileQueue(aLockedFile);
if (existingLockedFileQueue) {
existingLockedFileQueue->Enqueue(aFileHelper);
return NS_OK;
}
bool lockedForReading = fileStorageInfo->IsFileLockedForReading(fileName);
bool lockedForWriting = fileStorageInfo->IsFileLockedForWriting(fileName);
if (modeIsWrite) {
if (!lockedForWriting) {
fileStorageInfo->LockFileForWriting(fileName);
}
}
else {
if (!lockedForReading) {
fileStorageInfo->LockFileForReading(fileName);
}
}
if (lockedForWriting || (lockedForReading && modeIsWrite)) {
fileStorageInfo->CreateDelayedEnqueueInfo(aLockedFile, aFileHelper);
}
else {
LockedFileQueue* lockedFileQueue =
fileStorageInfo->CreateLockedFileQueue(aLockedFile);
if (aFileHelper) {
// Enqueue() will queue the file helper if there's already something
// running. That can't fail, so no need to eventually remove
// fileStorageInfo from the hash table.
//
// If the file helper is free to run then AsyncRun() is called on the
// file helper. AsyncRun() is responsible for calling all necessary
// callbacks when something fails. We're propagating the error here,
// however there's no need to eventually remove fileStorageInfo from
// the hash table. Code behind AsyncRun() will take care of it. The last
// item in the code path is NotifyLockedFileCompleted() which removes
// fileStorageInfo from the hash table if there are no locked files for
// the file storage.
nsresult rv = lockedFileQueue->Enqueue(aFileHelper);
NS_ENSURE_SUCCESS(rv, rv);
}
}
return NS_OK;
}
void
FileService::NotifyLockedFileCompleted(LockedFile* aLockedFile)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(aLockedFile, "Null pointer!");
FileHandle* fileHandle = aLockedFile->mFileHandle;
nsIAtom* storageId = fileHandle->mFileStorage->Id();
FileStorageInfo* fileStorageInfo;
if (!mFileStorageInfos.Get(storageId, &fileStorageInfo)) {
NS_ERROR("We don't know anyting about this locked file?!");
return;
}
fileStorageInfo->RemoveLockedFileQueue(aLockedFile);
if (!fileStorageInfo->HasRunningLockedFiles()) {
mFileStorageInfos.Remove(storageId);
#ifdef DEBUG
storageId = nullptr;
#endif
// See if we need to fire any complete callbacks.
uint32_t index = 0;
while (index < mCompleteCallbacks.Length()) {
if (MaybeFireCallback(mCompleteCallbacks[index])) {
mCompleteCallbacks.RemoveElementAt(index);
}
else {
index++;
}
}
}
}
void
FileService::WaitForStoragesToComplete(
nsTArray<nsCOMPtr<nsIFileStorage> >& aStorages,
nsIRunnable* aCallback)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(!aStorages.IsEmpty(), "No databases to wait on!");
NS_ASSERTION(aCallback, "Null pointer!");
StoragesCompleteCallback* callback = mCompleteCallbacks.AppendElement();
callback->mCallback = aCallback;
callback->mStorages.SwapElements(aStorages);
if (MaybeFireCallback(*callback)) {
mCompleteCallbacks.RemoveElementAt(mCompleteCallbacks.Length() - 1);
}
}
void
FileService::AbortLockedFilesForStorage(nsIFileStorage* aFileStorage)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(aFileStorage, "Null pointer!");
FileStorageInfo* fileStorageInfo;
if (!mFileStorageInfos.Get(aFileStorage->Id(), &fileStorageInfo)) {
return;
}
nsAutoTArray<nsRefPtr<LockedFile>, 10> lockedFiles;
fileStorageInfo->CollectRunningAndDelayedLockedFiles(aFileStorage,
lockedFiles);
for (uint32_t index = 0; index < lockedFiles.Length(); index++) {
lockedFiles[index]->Abort();
}
}
bool
FileService::HasLockedFilesForStorage(nsIFileStorage* aFileStorage)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(aFileStorage, "Null pointer!");
FileStorageInfo* fileStorageInfo;
if (!mFileStorageInfos.Get(aFileStorage->Id(), &fileStorageInfo)) {
return false;
}
return fileStorageInfo->HasRunningLockedFiles(aFileStorage);
}
NS_IMPL_ISUPPORTS1(FileService, nsIObserver)
NS_IMETHODIMP
FileService::Observe(nsISupports* aSubject, const char* aTopic,
const PRUnichar* aData)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(!strcmp(aTopic, "profile-before-change"), "Wrong topic!");
Shutdown();
return NS_OK;
}
bool
FileService::MaybeFireCallback(StoragesCompleteCallback& aCallback)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
for (uint32_t index = 0; index < aCallback.mStorages.Length(); index++) {
if (mFileStorageInfos.Get(aCallback.mStorages[index]->Id(), nullptr)) {
return false;
}
}
aCallback.mCallback->Run();
return true;
}
FileService::LockedFileQueue::LockedFileQueue(LockedFile* aLockedFile)
: mLockedFile(aLockedFile)
{
NS_ASSERTION(aLockedFile, "Null pointer!");
}
NS_IMPL_THREADSAFE_ADDREF(FileService::LockedFileQueue)
NS_IMPL_THREADSAFE_RELEASE(FileService::LockedFileQueue)
nsresult
FileService::LockedFileQueue::Enqueue(FileHelper* aFileHelper)
{
mQueue.AppendElement(aFileHelper);
nsresult rv;
if (mLockedFile->mRequestMode == LockedFile::PARALLEL) {
rv = aFileHelper->AsyncRun(this);
}
else {
rv = ProcessQueue();
}
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
void
FileService::LockedFileQueue::OnFileHelperComplete(FileHelper* aFileHelper)
{
if (mLockedFile->mRequestMode == LockedFile::PARALLEL) {
int32_t index = mQueue.IndexOf(aFileHelper);
NS_ASSERTION(index != -1, "We don't know anything about this helper!");
mQueue.RemoveElementAt(index);
}
else {
NS_ASSERTION(mCurrentHelper == aFileHelper, "How can this happen?!");
mCurrentHelper = nullptr;
nsresult rv = ProcessQueue();
if (NS_FAILED(rv)) {
return;
}
}
}
nsresult
FileService::LockedFileQueue::ProcessQueue()
{
if (mQueue.IsEmpty() || mCurrentHelper) {
return NS_OK;
}
mCurrentHelper = mQueue[0];
mQueue.RemoveElementAt(0);
nsresult rv = mCurrentHelper->AsyncRun(this);
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
FileService::LockedFileQueue*
FileService::FileStorageInfo::CreateLockedFileQueue(LockedFile* aLockedFile)
{
nsRefPtr<LockedFileQueue>* lockedFileQueue =
mLockedFileQueues.AppendElement();
*lockedFileQueue = new LockedFileQueue(aLockedFile);
return lockedFileQueue->get();
}
FileService::LockedFileQueue*
FileService::FileStorageInfo::GetLockedFileQueue(LockedFile* aLockedFile)
{
uint32_t count = mLockedFileQueues.Length();
for (uint32_t index = 0; index < count; index++) {
nsRefPtr<LockedFileQueue>& lockedFileQueue = mLockedFileQueues[index];
if (lockedFileQueue->mLockedFile == aLockedFile) {
return lockedFileQueue;
}
}
return nullptr;
}
void
FileService::FileStorageInfo::RemoveLockedFileQueue(LockedFile* aLockedFile)
{
for (uint32_t index = 0; index < mDelayedEnqueueInfos.Length(); index++) {
if (mDelayedEnqueueInfos[index].mLockedFile == aLockedFile) {
NS_ASSERTION(!mDelayedEnqueueInfos[index].mFileHelper, "Should be null!");
mDelayedEnqueueInfos.RemoveElementAt(index);
return;
}
}
uint32_t lockedFileCount = mLockedFileQueues.Length();
// We can't just remove entries from lock hash tables, we have to rebuild
// them instead. Multiple LockedFile objects may lock the same file
// (one entry can represent multiple locks).
mFilesReading.Clear();
mFilesWriting.Clear();
for (uint32_t index = 0, count = lockedFileCount; index < count; index++) {
LockedFile* lockedFile = mLockedFileQueues[index]->mLockedFile;
if (lockedFile == aLockedFile) {
NS_ASSERTION(count == lockedFileCount, "More than one match?!");
mLockedFileQueues.RemoveElementAt(index);
index--;
count--;
continue;
}
const nsAString& fileName = lockedFile->mFileHandle->mFileName;
if (lockedFile->mMode == FileMode::Readwrite) {
if (!IsFileLockedForWriting(fileName)) {
LockFileForWriting(fileName);
}
}
else {
if (!IsFileLockedForReading(fileName)) {
LockFileForReading(fileName);
}
}
}
NS_ASSERTION(mLockedFileQueues.Length() == lockedFileCount - 1,
"Didn't find the locked file we were looking for!");
nsTArray<DelayedEnqueueInfo> delayedEnqueueInfos;
delayedEnqueueInfos.SwapElements(mDelayedEnqueueInfos);
for (uint32_t index = 0; index < delayedEnqueueInfos.Length(); index++) {
DelayedEnqueueInfo& delayedEnqueueInfo = delayedEnqueueInfos[index];
if (NS_FAILED(gInstance->Enqueue(delayedEnqueueInfo.mLockedFile,
delayedEnqueueInfo.mFileHelper))) {
NS_WARNING("Enqueue failed!");
}
}
}
bool
FileService::FileStorageInfo::HasRunningLockedFiles(
nsIFileStorage* aFileStorage)
{
for (uint32_t index = 0; index < mLockedFileQueues.Length(); index++) {
LockedFile* lockedFile = mLockedFileQueues[index]->mLockedFile;
if (lockedFile->mFileHandle->mFileStorage == aFileStorage) {
return true;
}
}
return false;
}
FileService::DelayedEnqueueInfo*
FileService::FileStorageInfo::CreateDelayedEnqueueInfo(LockedFile* aLockedFile,
FileHelper* aFileHelper)
{
DelayedEnqueueInfo* info = mDelayedEnqueueInfos.AppendElement();
info->mLockedFile = aLockedFile;
info->mFileHelper = aFileHelper;
return info;
}
void
FileService::FileStorageInfo::CollectRunningAndDelayedLockedFiles(
nsIFileStorage* aFileStorage,
nsTArray<nsRefPtr<LockedFile> >& aLockedFiles)
{
for (uint32_t index = 0; index < mLockedFileQueues.Length(); index++) {
LockedFile* lockedFile = mLockedFileQueues[index]->mLockedFile;
if (lockedFile->mFileHandle->mFileStorage == aFileStorage) {
aLockedFiles.AppendElement(lockedFile);
}
}
for (uint32_t index = 0; index < mDelayedEnqueueInfos.Length(); index++) {
LockedFile* lockedFile = mDelayedEnqueueInfos[index].mLockedFile;
if (lockedFile->mFileHandle->mFileStorage == aFileStorage) {
aLockedFiles.AppendElement(lockedFile);
}
}
}