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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
* 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
#include "BaseVFS.h"
#include "mozilla/Attributes.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/SpinEventLoopUntil.h"
#include "nsIFile.h"
#include "nsIFileURL.h"
#include "mozStorageService.h"
#include "mozStorageConnection.h"
#include "nsComponentManagerUtils.h"
#include "nsEmbedCID.h"
#include "nsExceptionHandler.h"
#include "nsThreadUtils.h"
#include "mozStoragePrivateHelpers.h"
#include "nsIObserverService.h"
#include "nsIPropertyBag2.h"
#include "ObfuscatingVFS.h"
#include "QuotaVFS.h"
#include "mozilla/Services.h"
#include "mozilla/LateWriteChecks.h"
#include "mozIStorageCompletionCallback.h"
#include "mozIStoragePendingStatement.h"
#include "mozilla/StaticPrefs_storage.h"
#include "mozilla/intl/Collator.h"
#include "mozilla/intl/LocaleService.h"
#include "sqlite3.h"
#include "mozilla/AutoSQLiteLifetime.h"
#ifdef XP_WIN
// "windows.h" was included and it can #define lots of things we care about...
# undef CompareString
#endif
using mozilla::intl::Collator;
namespace mozilla::storage {
////////////////////////////////////////////////////////////////////////////////
//// Memory Reporting
#ifdef MOZ_DMD
mozilla::Atomic<size_t> gSqliteMemoryUsed;
#endif
static int64_t StorageSQLiteDistinguishedAmount() {
return ::sqlite3_memory_used();
}
/**
* Passes a single SQLite memory statistic to a memory reporter callback.
*
* @param aHandleReport
* The callback.
* @param aData
* The data for the callback.
* @param aConn
* The SQLite connection.
* @param aPathHead
* Head of the path for the memory report.
* @param aKind
* The memory report statistic kind, one of "stmt", "cache" or
* "schema".
* @param aDesc
* The memory report description.
* @param aOption
* The SQLite constant for getting the measurement.
* @param aTotal
* The accumulator for the measurement.
*/
static void ReportConn(nsIHandleReportCallback* aHandleReport,
nsISupports* aData, Connection* aConn,
const nsACString& aPathHead, const nsACString& aKind,
const nsACString& aDesc, int32_t aOption,
size_t* aTotal) {
nsCString path(aPathHead);
path.Append(aKind);
path.AppendLiteral("-used");
int32_t val = aConn->getSqliteRuntimeStatus(aOption);
aHandleReport->Callback(""_ns, path, nsIMemoryReporter::KIND_HEAP,
nsIMemoryReporter::UNITS_BYTES, int64_t(val), aDesc,
aData);
*aTotal += val;
}
// Warning: To get a Connection's measurements requires holding its lock.
// There may be a delay getting the lock if another thread is accessing the
// Connection. This isn't very nice if CollectReports is called from the main
// thread! But at the time of writing this function is only called when
// about:memory is loaded (not, for example, when telemetry pings occur) and
// any delays in that case aren't so bad.
NS_IMETHODIMP
Service::CollectReports(nsIHandleReportCallback* aHandleReport,
nsISupports* aData, bool aAnonymize) {
size_t totalConnSize = 0;
{
nsTArray<RefPtr<Connection>> connections;
getConnections(connections);
for (uint32_t i = 0; i < connections.Length(); i++) {
RefPtr<Connection>& conn = connections[i];
// Someone may have closed the Connection, in which case we skip it.
// Note that we have consumers of the synchronous API that are off the
// main-thread, like the DOM Cache and IndexedDB, and as such we must be
// sure that we have a connection.
MutexAutoLock lockedAsyncScope(conn->sharedAsyncExecutionMutex);
if (!conn->connectionReady()) {
continue;
}
nsCString pathHead("explicit/storage/sqlite/");
// This filename isn't privacy-sensitive, and so is never anonymized.
pathHead.Append(conn->getFilename());
pathHead.Append('/');
SQLiteMutexAutoLock lockedScope(conn->sharedDBMutex);
constexpr auto stmtDesc =
"Memory (approximate) used by all prepared statements used by "
"connections to this database."_ns;
ReportConn(aHandleReport, aData, conn, pathHead, "stmt"_ns, stmtDesc,
SQLITE_DBSTATUS_STMT_USED, &totalConnSize);
constexpr auto cacheDesc =
"Memory (approximate) used by all pager caches used by connections "
"to this database."_ns;
ReportConn(aHandleReport, aData, conn, pathHead, "cache"_ns, cacheDesc,
SQLITE_DBSTATUS_CACHE_USED_SHARED, &totalConnSize);
constexpr auto schemaDesc =
"Memory (approximate) used to store the schema for all databases "
"associated with connections to this database."_ns;
ReportConn(aHandleReport, aData, conn, pathHead, "schema"_ns, schemaDesc,
SQLITE_DBSTATUS_SCHEMA_USED, &totalConnSize);
}
#ifdef MOZ_DMD
if (::sqlite3_memory_used() != int64_t(gSqliteMemoryUsed)) {
NS_WARNING(
"memory consumption reported by SQLite doesn't match "
"our measurements");
}
#endif
}
int64_t other = static_cast<int64_t>(::sqlite3_memory_used() - totalConnSize);
MOZ_COLLECT_REPORT("explicit/storage/sqlite/other", KIND_HEAP, UNITS_BYTES,
other, "All unclassified sqlite memory.");
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
//// Service
NS_IMPL_ISUPPORTS(Service, mozIStorageService, nsIObserver, nsIMemoryReporter)
Service* Service::gService = nullptr;
already_AddRefed<Service> Service::getSingleton() {
if (gService) {
return do_AddRef(gService);
}
// The first reference to the storage service must be obtained on the
// main thread.
NS_ENSURE_TRUE(NS_IsMainThread(), nullptr);
RefPtr<Service> service = new Service();
if (NS_SUCCEEDED(service->initialize())) {
// Note: This is cleared in the Service destructor.
gService = service.get();
return service.forget();
}
return nullptr;
}
int Service::AutoVFSRegistration::Init(UniquePtr<sqlite3_vfs> aVFS) {
MOZ_ASSERT(!mVFS);
if (aVFS) {
mVFS = std::move(aVFS);
return sqlite3_vfs_register(mVFS.get(), 0);
}
NS_WARNING("Failed to register VFS");
return SQLITE_OK;
}
Service::AutoVFSRegistration::~AutoVFSRegistration() {
if (mVFS) {
int rc = sqlite3_vfs_unregister(mVFS.get());
if (rc != SQLITE_OK) {
NS_WARNING("Failed to unregister sqlite vfs wrapper.");
}
}
}
Service::Service()
: mMutex("Service::mMutex"),
mRegistrationMutex("Service::mRegistrationMutex"),
mLastSensitivity(mozilla::intl::Collator::Sensitivity::Base) {}
Service::~Service() {
mozilla::UnregisterWeakMemoryReporter(this);
mozilla::UnregisterStorageSQLiteDistinguishedAmount();
gService = nullptr;
}
void Service::registerConnection(Connection* aConnection) {
mRegistrationMutex.AssertNotCurrentThreadOwns();
MutexAutoLock mutex(mRegistrationMutex);
(void)mConnections.AppendElement(aConnection);
}
void Service::unregisterConnection(Connection* aConnection) {
// If this is the last Connection it might be the only thing keeping Service
// alive. So ensure that Service is destroyed only after the Connection is
// cleanly unregistered and destroyed.
RefPtr<Service> kungFuDeathGrip(this);
RefPtr<Connection> forgettingRef;
{
mRegistrationMutex.AssertNotCurrentThreadOwns();
MutexAutoLock mutex(mRegistrationMutex);
for (uint32_t i = 0; i < mConnections.Length(); ++i) {
if (mConnections[i] == aConnection) {
// Because dropping the final reference can potentially result in
// spinning a nested event loop if the connection was not properly
// shutdown, we want to do that outside this loop so that we can finish
// mutating the array and drop our mutex.
forgettingRef = std::move(mConnections[i]);
mConnections.RemoveElementAt(i);
break;
}
}
}
MOZ_ASSERT(forgettingRef,
"Attempt to unregister unknown storage connection!");
// Do not proxy the release anywhere, just let this reference drop here. (We
// previously did proxy the release, but that was because we invoked Close()
// in the destructor and Close() likes to complain if it's not invoked on the
// opener event target, so it was essential that the last reference be dropped
// on the opener event target. We now enqueue Close() inside our caller,
// Release(), so it doesn't actually matter what thread our reference drops
// on.)
}
void Service::getConnections(
/* inout */ nsTArray<RefPtr<Connection>>& aConnections) {
mRegistrationMutex.AssertNotCurrentThreadOwns();
MutexAutoLock mutex(mRegistrationMutex);
aConnections.Clear();
aConnections.AppendElements(mConnections);
}
void Service::minimizeMemory() {
nsTArray<RefPtr<Connection>> connections;
getConnections(connections);
for (uint32_t i = 0; i < connections.Length(); i++) {
RefPtr<Connection> conn = connections[i];
// For non-main-thread owning/opening threads, we may be racing against them
// closing their connection or their thread. That's okay, see below.
if (!conn->connectionReady()) {
continue;
}
constexpr auto shrinkPragma = "PRAGMA shrink_memory"_ns;
if (!conn->operationSupported(Connection::SYNCHRONOUS)) {
// This is a mozIStorageAsyncConnection, it can only be used on the main
// thread, so we can do a straight API call.
nsCOMPtr<mozIStoragePendingStatement> ps;
DebugOnly<nsresult> rv = conn->ExecuteSimpleSQLAsync(
shrinkPragma, nullptr, getter_AddRefs(ps));
MOZ_ASSERT(NS_SUCCEEDED(rv), "Should have purged sqlite caches");
} else if (IsOnCurrentSerialEventTarget(conn->eventTargetOpenedOn)) {
if (conn->isAsyncExecutionThreadAvailable()) {
nsCOMPtr<mozIStoragePendingStatement> ps;
DebugOnly<nsresult> rv = conn->ExecuteSimpleSQLAsync(
shrinkPragma, nullptr, getter_AddRefs(ps));
MOZ_ASSERT(NS_SUCCEEDED(rv), "Should have purged sqlite caches");
} else {
conn->ExecuteSimpleSQL(shrinkPragma);
}
} else {
// We are on the wrong event target, the query should be executed on the
// opener event target, so we must dispatch to it.
// It's possible the connection is already closed or will be closed by the
// time our runnable runs. ExecuteSimpleSQL will safely return with a
// failure in that case. If the event target is shutting down or shut
// down, the dispatch will fail and that's okay.
nsCOMPtr<nsIRunnable> event = NewRunnableMethod<const nsCString>(
"Connection::ExecuteSimpleSQL", conn, &Connection::ExecuteSimpleSQL,
shrinkPragma);
Unused << conn->eventTargetOpenedOn->Dispatch(event, NS_DISPATCH_NORMAL);
}
}
}
UniquePtr<sqlite3_vfs> ConstructReadOnlyNoLockVFS();
static const char* sObserverTopics[] = {"memory-pressure",
"xpcom-shutdown-threads"};
nsresult Service::initialize() {
MOZ_ASSERT(NS_IsMainThread(), "Must be initialized on the main thread");
int rc = AutoSQLiteLifetime::getInitResult();
if (rc != SQLITE_OK) {
return convertResultCode(rc);
}
/**
* The virtual file system hierarchy
*
* obfsvfs
* |
* |
* |
* quotavfs
* / \
* / \
* / \
* / \
* / \
* base-vfs-excl base-vfs
* / \ / \
* / \ / \
* / \ / \
* unix-excl win32 unix win32
*/
rc = mBaseSqliteVFS.Init(basevfs::ConstructVFS(false));
if (rc != SQLITE_OK) {
return convertResultCode(rc);
}
rc = mBaseExclSqliteVFS.Init(basevfs::ConstructVFS(true));
if (rc != SQLITE_OK) {
return convertResultCode(rc);
}
rc = mQuotaSqliteVFS.Init(quotavfs::ConstructVFS(basevfs::GetVFSName(
StaticPrefs::storage_sqlite_exclusiveLock_enabled())));
if (rc != SQLITE_OK) {
return convertResultCode(rc);
}
rc =
mObfuscatingSqliteVFS.Init(obfsvfs::ConstructVFS(quotavfs::GetVFSName()));
if (rc != SQLITE_OK) {
return convertResultCode(rc);
}
rc = mReadOnlyNoLockSqliteVFS.Init(ConstructReadOnlyNoLockVFS());
if (rc != SQLITE_OK) {
return convertResultCode(rc);
}
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
NS_ENSURE_TRUE(os, NS_ERROR_FAILURE);
for (auto& sObserverTopic : sObserverTopics) {
nsresult rv = os->AddObserver(this, sObserverTopic, false);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
}
mozilla::RegisterWeakMemoryReporter(this);
mozilla::RegisterStorageSQLiteDistinguishedAmount(
StorageSQLiteDistinguishedAmount);
return NS_OK;
}
int Service::localeCompareStrings(const nsAString& aStr1,
const nsAString& aStr2,
Collator::Sensitivity aSensitivity) {
// The mozilla::intl::Collator is not thread safe, since the Collator::Options
// can be changed.
MutexAutoLock mutex(mMutex);
Collator* collator = getCollator();
if (!collator) {
NS_ERROR("Storage service has no collation");
return 0;
}
if (aSensitivity != mLastSensitivity) {
Collator::Options options{};
options.sensitivity = aSensitivity;
auto result = mCollator->SetOptions(options);
if (result.isErr()) {
NS_WARNING("Could not configure the mozilla::intl::Collation.");
return 0;
}
mLastSensitivity = aSensitivity;
}
return collator->CompareStrings(aStr1, aStr2);
}
Collator* Service::getCollator() {
mMutex.AssertCurrentThreadOwns();
if (mCollator) {
return mCollator.get();
}
auto result = mozilla::intl::LocaleService::TryCreateComponent<Collator>();
if (result.isErr()) {
NS_WARNING("Could not create mozilla::intl::Collation.");
return nullptr;
}
mCollator = result.unwrap();
// Sort in a case-insensitive way, where "base" letters are considered
// equal, e.g: a = á, a = A, a ≠b.
Collator::Options options{};
options.sensitivity = Collator::Sensitivity::Base;
auto optResult = mCollator->SetOptions(options);
if (optResult.isErr()) {
NS_WARNING("Could not configure the mozilla::intl::Collation.");
mCollator = nullptr;
return nullptr;
}
return mCollator.get();
}
////////////////////////////////////////////////////////////////////////////////
//// mozIStorageService
NS_IMETHODIMP
Service::OpenSpecialDatabase(const nsACString& aStorageKey,
const nsACString& aName, uint32_t aConnectionFlags,
mozIStorageConnection** _connection) {
if (!aStorageKey.Equals(kMozStorageMemoryStorageKey)) {
return NS_ERROR_INVALID_ARG;
}
const bool interruptible =
aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
int flags = SQLITE_OPEN_READWRITE;
if (!aName.IsEmpty()) {
flags |= SQLITE_OPEN_URI;
}
RefPtr<Connection> msc =
new Connection(this, flags, Connection::SYNCHRONOUS,
kMozStorageMemoryStorageKey, interruptible);
const nsresult rv = msc->initialize(aStorageKey, aName);
NS_ENSURE_SUCCESS(rv, rv);
msc.forget(_connection);
return NS_OK;
}
namespace {
class AsyncInitDatabase final : public Runnable {
public:
AsyncInitDatabase(Connection* aConnection, nsIFile* aStorageFile,
int32_t aGrowthIncrement,
mozIStorageCompletionCallback* aCallback)
: Runnable("storage::AsyncInitDatabase"),
mConnection(aConnection),
mStorageFile(aStorageFile),
mGrowthIncrement(aGrowthIncrement),
mCallback(aCallback) {
MOZ_ASSERT(NS_IsMainThread());
}
NS_IMETHOD Run() override {
MOZ_ASSERT(!NS_IsMainThread());
nsresult rv = mConnection->initializeOnAsyncThread(mStorageFile);
if (NS_FAILED(rv)) {
return DispatchResult(rv, nullptr);
}
if (mGrowthIncrement >= 0) {
// Ignore errors. In the future, we might wish to log them.
(void)mConnection->SetGrowthIncrement(mGrowthIncrement, ""_ns);
}
return DispatchResult(
NS_OK, NS_ISUPPORTS_CAST(mozIStorageAsyncConnection*, mConnection));
}
private:
nsresult DispatchResult(nsresult aStatus, nsISupports* aValue) {
RefPtr<CallbackComplete> event =
new CallbackComplete(aStatus, aValue, mCallback.forget());
return NS_DispatchToMainThread(event);
}
~AsyncInitDatabase() {
NS_ReleaseOnMainThread("AsyncInitDatabase::mStorageFile",
mStorageFile.forget());
NS_ReleaseOnMainThread("AsyncInitDatabase::mConnection",
mConnection.forget());
// Generally, the callback will be released by CallbackComplete.
// However, if for some reason Run() is not executed, we still
// need to ensure that it is released here.
NS_ReleaseOnMainThread("AsyncInitDatabase::mCallback", mCallback.forget());
}
RefPtr<Connection> mConnection;
nsCOMPtr<nsIFile> mStorageFile;
int32_t mGrowthIncrement;
RefPtr<mozIStorageCompletionCallback> mCallback;
};
} // namespace
NS_IMETHODIMP
Service::OpenAsyncDatabase(nsIVariant* aDatabaseStore, uint32_t aOpenFlags,
uint32_t /* aConnectionFlags */,
mozIStorageCompletionCallback* aCallback) {
if (!NS_IsMainThread()) {
return NS_ERROR_NOT_SAME_THREAD;
}
NS_ENSURE_ARG(aDatabaseStore);
NS_ENSURE_ARG(aCallback);
const bool shared = aOpenFlags & mozIStorageService::OPEN_SHARED;
const bool ignoreLockingMode =
aOpenFlags & mozIStorageService::OPEN_IGNORE_LOCKING_MODE;
// Specifying ignoreLockingMode will force use of the readOnly flag:
const bool readOnly =
ignoreLockingMode || (aOpenFlags & mozIStorageService::OPEN_READONLY);
const bool openNotExclusive =
aOpenFlags & mozIStorageService::OPEN_NOT_EXCLUSIVE;
int flags = readOnly ? SQLITE_OPEN_READONLY : SQLITE_OPEN_READWRITE;
nsCOMPtr<nsIFile> storageFile;
nsCOMPtr<nsISupports> dbStore;
nsresult rv = aDatabaseStore->GetAsISupports(getter_AddRefs(dbStore));
if (NS_SUCCEEDED(rv)) {
// Generally, aDatabaseStore holds the database nsIFile.
storageFile = do_QueryInterface(dbStore, &rv);
if (NS_FAILED(rv)) {
return NS_ERROR_INVALID_ARG;
}
nsCOMPtr<nsIFile> cloned;
rv = storageFile->Clone(getter_AddRefs(cloned));
MOZ_ASSERT(NS_SUCCEEDED(rv));
storageFile = std::move(cloned);
if (!readOnly) {
// Ensure that SQLITE_OPEN_CREATE is passed in for compatibility reasons.
flags |= SQLITE_OPEN_CREATE;
}
// Apply the shared-cache option.
flags |= shared ? SQLITE_OPEN_SHAREDCACHE : SQLITE_OPEN_PRIVATECACHE;
} else {
// Sometimes, however, it's a special database name.
nsAutoCString keyString;
rv = aDatabaseStore->GetAsACString(keyString);
if (NS_FAILED(rv) || !keyString.Equals(kMozStorageMemoryStorageKey)) {
return NS_ERROR_INVALID_ARG;
}
// Just fall through with nullptr storageFile, this will cause the storage
// connection to use a memory DB.
}
// Create connection on this thread, but initialize it on its helper thread.
nsAutoCString telemetryFilename;
if (!storageFile) {
telemetryFilename.Assign(kMozStorageMemoryStorageKey);
} else {
rv = storageFile->GetNativeLeafName(telemetryFilename);
NS_ENSURE_SUCCESS(rv, rv);
}
RefPtr<Connection> msc = new Connection(
this, flags, Connection::ASYNCHRONOUS, telemetryFilename,
/* interruptible */ true, ignoreLockingMode, openNotExclusive);
nsCOMPtr<nsIEventTarget> target = msc->getAsyncExecutionTarget();
MOZ_ASSERT(target,
"Cannot initialize a connection that has been closed already");
RefPtr<AsyncInitDatabase> asyncInit = new AsyncInitDatabase(
msc, storageFile, /* growthIncrement */ -1, aCallback);
return target->Dispatch(asyncInit, nsIEventTarget::DISPATCH_NORMAL);
}
NS_IMETHODIMP
Service::OpenDatabase(nsIFile* aDatabaseFile, uint32_t aConnectionFlags,
mozIStorageConnection** _connection) {
NS_ENSURE_ARG(aDatabaseFile);
const bool interruptible =
aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
// Always ensure that SQLITE_OPEN_CREATE is passed in for compatibility
// reasons.
const int flags =
SQLITE_OPEN_READWRITE | SQLITE_OPEN_SHAREDCACHE | SQLITE_OPEN_CREATE;
nsAutoCString telemetryFilename;
nsresult rv = aDatabaseFile->GetNativeLeafName(telemetryFilename);
NS_ENSURE_SUCCESS(rv, rv);
RefPtr<Connection> msc = new Connection(this, flags, Connection::SYNCHRONOUS,
telemetryFilename, interruptible);
rv = msc->initialize(aDatabaseFile);
NS_ENSURE_SUCCESS(rv, rv);
msc.forget(_connection);
return NS_OK;
}
NS_IMETHODIMP
Service::OpenUnsharedDatabase(nsIFile* aDatabaseFile, uint32_t aConnectionFlags,
mozIStorageConnection** _connection) {
NS_ENSURE_ARG(aDatabaseFile);
const bool interruptible =
aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
// Always ensure that SQLITE_OPEN_CREATE is passed in for compatibility
// reasons.
const int flags =
SQLITE_OPEN_READWRITE | SQLITE_OPEN_PRIVATECACHE | SQLITE_OPEN_CREATE;
nsAutoCString telemetryFilename;
nsresult rv = aDatabaseFile->GetNativeLeafName(telemetryFilename);
NS_ENSURE_SUCCESS(rv, rv);
RefPtr<Connection> msc = new Connection(this, flags, Connection::SYNCHRONOUS,
telemetryFilename, interruptible);
rv = msc->initialize(aDatabaseFile);
NS_ENSURE_SUCCESS(rv, rv);
msc.forget(_connection);
return NS_OK;
}
NS_IMETHODIMP
Service::OpenDatabaseWithFileURL(nsIFileURL* aFileURL,
const nsACString& aTelemetryFilename,
uint32_t aConnectionFlags,
mozIStorageConnection** _connection) {
NS_ENSURE_ARG(aFileURL);
const bool interruptible =
aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
// Always ensure that SQLITE_OPEN_CREATE is passed in for compatibility
// reasons.
const int flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_SHAREDCACHE |
SQLITE_OPEN_CREATE | SQLITE_OPEN_URI;
nsresult rv;
nsAutoCString telemetryFilename;
if (!aTelemetryFilename.IsEmpty()) {
telemetryFilename = aTelemetryFilename;
} else {
nsCOMPtr<nsIFile> databaseFile;
rv = aFileURL->GetFile(getter_AddRefs(databaseFile));
NS_ENSURE_SUCCESS(rv, rv);
rv = databaseFile->GetNativeLeafName(telemetryFilename);
NS_ENSURE_SUCCESS(rv, rv);
}
RefPtr<Connection> msc = new Connection(this, flags, Connection::SYNCHRONOUS,
telemetryFilename, interruptible);
rv = msc->initialize(aFileURL);
NS_ENSURE_SUCCESS(rv, rv);
msc.forget(_connection);
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
//// nsIObserver
NS_IMETHODIMP
Service::Observe(nsISupports*, const char* aTopic, const char16_t*) {
if (strcmp(aTopic, "memory-pressure") == 0) {
minimizeMemory();
} else if (strcmp(aTopic, "xpcom-shutdown-threads") == 0) {
// The Service is kept alive by our strong observer references and
// references held by Connection instances. Since we're about to remove the
// former and then wait for the latter ones to go away, it behooves us to
// hold a strong reference to ourselves so our calls to getConnections() do
// not happen on a deleted object.
RefPtr<Service> kungFuDeathGrip = this;
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
for (auto& sObserverTopic : sObserverTopics) {
(void)os->RemoveObserver(this, sObserverTopic);
}
SpinEventLoopUntil("storage::Service::Observe(xpcom-shutdown-threads)"_ns,
[&]() -> bool {
// We must wait until all the closing connections are
// closed.
nsTArray<RefPtr<Connection>> connections;
getConnections(connections);
for (auto& conn : connections) {
if (conn->isClosing()) {
return false;
}
}
return true;
});
#ifdef DEBUG
nsTArray<RefPtr<Connection>> connections;
getConnections(connections);
for (uint32_t i = 0, n = connections.Length(); i < n; i++) {
if (!connections[i]->isClosed()) {
// getFilename is only the leaf name for the database file,
// so it shouldn't contain privacy-sensitive information.
CrashReporter::RecordAnnotationNSCString(
CrashReporter::Annotation::StorageConnectionNotClosed,
connections[i]->getFilename());
printf_stderr("Storage connection not closed: %s",
connections[i]->getFilename().get());
MOZ_CRASH();
}
}
#endif
}
return NS_OK;
}
} // namespace mozilla::storage