gecko-dev/toolkit/components/places/Database.h

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/* 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/. */
#ifndef mozilla_places_Database_h_
#define mozilla_places_Database_h_
#include "MainThreadUtils.h"
#include "nsWeakReference.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIObserver.h"
#include "nsIAsyncShutdown.h"
#include "mozilla/storage.h"
#include "mozilla/storage/StatementCache.h"
#include "mozilla/Attributes.h"
#include "nsIEventTarget.h"
// This is the schema version. Update it at any schema change and add a
// corresponding migrateVxx method below.
#define DATABASE_SCHEMA_VERSION 30
// Fired after Places inited.
#define TOPIC_PLACES_INIT_COMPLETE "places-init-complete"
// Fired when initialization fails due to a locked database.
#define TOPIC_DATABASE_LOCKED "places-database-locked"
// This topic is received when the profile is about to be lost. Places does
// initial shutdown work and notifies TOPIC_PLACES_SHUTDOWN to all listeners.
// Any shutdown work that requires the Places APIs should happen here.
#define TOPIC_PROFILE_CHANGE_TEARDOWN "profile-change-teardown"
// Fired when Places is shutting down. Any code should stop accessing Places
// APIs after this notification. If you need to listen for Places shutdown
// you should only use this notification, next ones are intended only for
// internal Places use.
#define TOPIC_PLACES_SHUTDOWN "places-shutdown"
// For Internal use only. Fired when connection is about to be closed, only
// cleanup tasks should run at this stage, nothing should be added to the
// database, nor APIs should be called.
#define TOPIC_PLACES_WILL_CLOSE_CONNECTION "places-will-close-connection"
// Fired when the connection has gone, nothing will work from now on.
#define TOPIC_PLACES_CONNECTION_CLOSED "places-connection-closed"
// Simulate profile-before-change. This topic may only be used by
// calling `observe` directly on the database. Used for testing only.
#define TOPIC_SIMULATE_PLACES_MUST_CLOSE_1 "test-simulate-places-shutdown-phase-1"
// Simulate profile-before-change. This topic may only be used by
// calling `observe` directly on the database. Used for testing only.
#define TOPIC_SIMULATE_PLACES_MUST_CLOSE_2 "test-simulate-places-shutdown-phase-2"
class nsIRunnable;
namespace mozilla {
namespace places {
enum JournalMode {
// Default SQLite journal mode.
JOURNAL_DELETE = 0
// Can reduce fsyncs on Linux when journal is deleted (See bug 460315).
// We fallback to this mode when WAL is unavailable.
, JOURNAL_TRUNCATE
// Unsafe in case of crashes on database swap or low memory.
, JOURNAL_MEMORY
// Can reduce number of fsyncs. We try to use this mode by default.
, JOURNAL_WAL
};
class DatabaseShutdown;
class Database final : public nsIObserver
, public nsSupportsWeakReference
{
typedef mozilla::storage::StatementCache<mozIStorageStatement> StatementCache;
typedef mozilla::storage::StatementCache<mozIStorageAsyncStatement> AsyncStatementCache;
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIOBSERVER
Database();
/**
* Initializes the database connection and the schema.
* In case of corruption the database is copied to a backup file and replaced.
*/
nsresult Init();
/**
* The AsyncShutdown client used by clients of this API to be informed of shutdown.
*/
already_AddRefed<nsIAsyncShutdownClient> GetConnectionShutdown();
/**
* Getter to use when instantiating the class.
*
* @return Singleton instance of this class.
*/
static already_AddRefed<Database> GetDatabase();
/**
* Returns last known database status.
*
* @return one of the nsINavHistoryService::DATABASE_STATUS_* constants.
*/
uint16_t GetDatabaseStatus() const
{
return mDatabaseStatus;
}
/**
* Returns a pointer to the storage connection.
*
* @return The connection handle.
*/
mozIStorageConnection* MainConn() const
{
return mMainConn;
}
/**
* Dispatches a runnable to the connection async thread, to be serialized
* with async statements.
*
* @param aEvent
* The runnable to be dispatched.
*/
void DispatchToAsyncThread(nsIRunnable* aEvent) const
{
if (mClosed) {
return;
}
nsCOMPtr<nsIEventTarget> target = do_GetInterface(mMainConn);
if (target) {
(void)target->Dispatch(aEvent, NS_DISPATCH_NORMAL);
}
}
//////////////////////////////////////////////////////////////////////////////
//// Statements Getters.
/**
* Gets a cached synchronous statement.
*
* @param aQuery
* SQL query literal.
* @return The cached statement.
* @note Always null check the result.
* @note Always use a scoper to reset the statement.
*/
template<int N>
already_AddRefed<mozIStorageStatement>
GetStatement(const char (&aQuery)[N]) const
{
nsDependentCString query(aQuery, N - 1);
return GetStatement(query);
}
/**
* Gets a cached synchronous statement.
*
* @param aQuery
* nsCString of SQL query.
* @return The cached statement.
* @note Always null check the result.
* @note Always use a scoper to reset the statement.
*/
already_AddRefed<mozIStorageStatement> GetStatement(const nsACString& aQuery) const;
/**
* Gets a cached asynchronous statement.
*
* @param aQuery
* SQL query literal.
* @return The cached statement.
* @note Always null check the result.
* @note AsyncStatements are automatically reset on execution.
*/
template<int N>
already_AddRefed<mozIStorageAsyncStatement>
GetAsyncStatement(const char (&aQuery)[N]) const
{
nsDependentCString query(aQuery, N - 1);
return GetAsyncStatement(query);
}
/**
* Gets a cached asynchronous statement.
*
* @param aQuery
* nsCString of SQL query.
* @return The cached statement.
* @note Always null check the result.
* @note AsyncStatements are automatically reset on execution.
*/
already_AddRefed<mozIStorageAsyncStatement> GetAsyncStatement(const nsACString& aQuery) const;
protected:
/**
* Finalizes the cached statements and closes the database connection.
* A TOPIC_PLACES_CONNECTION_CLOSED notification is fired when done.
*/
void Shutdown();
bool IsShutdownStarted() const;
/**
* Initializes the database file. If the database does not exist or is
* corrupt, a new one is created. In case of corruption it also creates a
* backup copy of the database.
*
* @param aStorage
* mozStorage service instance.
* @param aNewDatabaseCreated
* whether a new database file has been created.
*/
nsresult InitDatabaseFile(nsCOMPtr<mozIStorageService>& aStorage,
bool* aNewDatabaseCreated);
/**
* Creates a database backup and replaces the original file with a new
* one.
*
* @param aStorage
* mozStorage service instance.
*/
nsresult BackupAndReplaceDatabaseFile(nsCOMPtr<mozIStorageService>& aStorage);
/**
* Initializes the database. This performs any necessary migrations for the
* database. All migration is done inside a transaction that is rolled back
* if any error occurs.
* @param aDatabaseMigrated
* Whether a schema upgrade happened.
*/
nsresult InitSchema(bool* aDatabaseMigrated);
/**
* Creates bookmark roots in a new DB.
*/
nsresult CreateBookmarkRoots();
/**
* Initializes additionale SQLite functions, defined in SQLFunctions.h
*/
nsresult InitFunctions();
/**
* Initializes triggers defined in nsPlacesTriggers.h
*/
nsresult InitTempTriggers();
/**
* Helpers used by schema upgrades.
*/
nsresult MigrateV13Up();
nsresult MigrateV15Up();
nsresult MigrateV17Up();
nsresult MigrateV18Up();
nsresult MigrateV19Up();
nsresult MigrateV20Up();
nsresult MigrateV21Up();
nsresult MigrateV22Up();
nsresult MigrateV23Up();
nsresult MigrateV24Up();
nsresult MigrateV25Up();
nsresult MigrateV26Up();
nsresult MigrateV27Up();
nsresult MigrateV28Up();
nsresult MigrateV30Up();
nsresult UpdateBookmarkRootTitles();
friend class DatabaseShutdown;
private:
~Database();
/**
* Singleton getter, invoked by class instantiation.
*/
static already_AddRefed<Database> GetSingleton();
static Database* gDatabase;
nsCOMPtr<mozIStorageConnection> mMainConn;
mutable StatementCache mMainThreadStatements;
mutable AsyncStatementCache mMainThreadAsyncStatements;
mutable StatementCache mAsyncThreadStatements;
int32_t mDBPageSize;
uint16_t mDatabaseStatus;
bool mClosed;
/**
* Determine at which shutdown phase we need to start shutting down
* the Database.
*/
already_AddRefed<nsIAsyncShutdownClient> GetShutdownPhase();
/**
* A companion object in charge of shutting down the mozStorage
* connection once all clients have disconnected.
*
* Cycles between `this` and `mConnectionShutdown` are broken
* in `Shutdown()`.
*/
nsRefPtr<DatabaseShutdown> mConnectionShutdown;
};
} // namespace places
} // namespace mozilla
#endif // mozilla_places_Database_h_