// deleteDatabaseFile has to release locks between looking up the list of databases to close and closing them. While this is in progress, the caller
// is responsible for making sure no new databases are opened in the file to be deleted.
bool DatabaseTracker::deleteDatabaseFile(SecurityOrigin* origin, const String& name, DeletionMode deletionMode)
{
String fullPath = fullPathForDatabase(origin, name, false);
if (fullPath.isEmpty())
return true;
#ifndef NDEBUG
{
LockHolder lockDatabase(m_databaseGuard);
ASSERT(isDeletingDatabaseOrOriginFor(origin, name));
}
#endif
Vector<RefPtr<Database>> deletedDatabases;
// Make sure not to hold the any locks when calling
// Database::markAsDeletedAndClose(), since that can cause a deadlock
// during the synchronous DatabaseThread call it triggers.
{
LockHolder openDatabaseMapLock(m_openDatabaseMapGuard);
if (m_openDatabaseMap) {
// There are some open databases, lets check if they are for this origin.
DatabaseNameMap* nameMap = m_openDatabaseMap->get(origin);
if (nameMap && nameMap->size()) {
// There are some open databases for this origin, let's check
// if they are this database by name.
DatabaseSet* databaseSet = nameMap->get(name);
if (databaseSet && databaseSet->size()) {
// We have some database open with this name. Mark them as deleted.
for (auto& database : *databaseSet)
deletedDatabases.append(database);
}
}
}
}
for (auto& database : deletedDatabases)
database->markAsDeletedAndClose();
#if PLATFORM(IOS)
if (deletionMode == DeletionMode::Deferred) {
// On the phone, other background processes may still be accessing this database. Deleting the database directly
// would nuke the POSIX file locks, potentially causing Safari/WebApp to corrupt the new db if it's running in the background.
// We'll instead truncate the database file to 0 bytes. If another process is operating on this same database file after
// the truncation, it should get an error since the database file is no longer valid. When Safari is launched
// next time, it'll go through the database files and clean up any zero-bytes ones.
SQLiteDatabase database;
if (!database.open(fullPath))
return false;
return SQLiteFileSystem::truncateDatabaseFile(database.sqlite3Handle());
}
#else
UNUSED_PARAM(deletionMode);
#endif
return SQLiteFileSystem::deleteDatabaseFile(fullPath);
}
static void truncateDatabaseFile(SQLiteDatabase& database)
{
sqlite3_file_control(database.sqlite3Handle(), 0, SQLITE_TRUNCATE_DATABASE, 0);
}