gecko-dev/storage/public/mozIStorageService.idl

194 строки
7.9 KiB
Plaintext

/* -*- Mode: idl; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsISupports.idl"
interface mozIStorageConnection;
interface nsIFile;
interface nsIFileURL;
interface nsIPropertyBag2;
interface nsIVariant;
interface mozIStorageCompletionCallback;
/**
* The mozIStorageService interface is intended to be implemented by
* a service that can create storage connections (mozIStorageConnection)
* to either a well-known profile database or to a specific database file.
*
* This is the only way to open a database connection.
*
* @note The first reference to mozIStorageService must be made on the main
* thread.
*/
[scriptable, uuid(07b6b2f5-6d97-47b4-9584-e65bc467fe9e)]
interface mozIStorageService : nsISupports {
/**
* Open an asynchronous connection to a database.
*
* This method MUST be called from the main thread. The connection object
* returned by this function is not threadsafe. You MUST use it only from
* the main thread.
*
* If you have more than one connection to a file, you MUST use the EXACT
* SAME NAME for the file each time, including case. The sqlite code uses
* a simple string compare to see if there is already a connection. Opening
* a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
*
* @param aDatabaseStore Either a nsIFile representing the file that contains
* the database or a special string to open a special database. The special
* string may be:
* - "memory" to open an in-memory database.
*
* @param aOptions A set of options (may be null). Options may contain:
* - bool shared (defaults to |false|).
* -- If |true|, opens the database with a shared-cache. The
* shared-cache mode is more memory-efficient when many
* connections to the same database are expected, though, the
* connections will contend the cache resource. In any cases
* where performance matter, working without a shared-cache will
* improve concurrency. @see openUnsharedDatabase
*
* - int growthIncrement (defaults to none).
* -- Set the growth increment for the main database. This hints SQLite to
* grow the database file by a given chunk size and may reduce
* filesystem fragmentation on large databases.
* @see mozIStorageConnection::setGrowthIncrement
*
* @param aCallback A callback that will receive the result of the operation.
* In case of error, it may receive as status:
* - NS_ERROR_OUT_OF_MEMORY if allocating a new storage object fails.
* - NS_ERROR_FILE_CORRUPTED if the database file is corrupted.
* In case of success, it receives as argument the new database
* connection, as an instance of |mozIStorageAsyncConnection|.
*
* @throws NS_ERROR_INVALID_ARG if |aDatabaseStore| is neither a file nor
* one of the special strings understood by this method, or if one of
* the options passed through |aOptions| does not have the right type.
* @throws NS_ERROR_NOT_SAME_THREAD if called from a thread other than the
* main thread.
*/
void openAsyncDatabase(in nsIVariant aDatabaseStore,
[optional] in nsIPropertyBag2 aOptions,
in mozIStorageCompletionCallback aCallback);
/**
* Get a connection to a named special database storage.
*
* @param aStorageKey a string key identifying the type of storage
* requested. Valid values include: "memory".
*
* @see openDatabase for restrictions on how database connections may be
* used. For the profile database, you should only access it from the main
* thread since other callers may also have connections.
*
* @returns a new mozIStorageConnection for the requested
* storage database.
*
* @throws NS_ERROR_INVALID_ARG if aStorageKey is invalid.
*/
mozIStorageConnection openSpecialDatabase(in string aStorageKey);
/**
* Open a connection to the specified file.
*
* Consumers should check mozIStorageConnection::connectionReady to ensure
* that they can use the database. If this value is false, it is strongly
* recommended that the database be backed up with
* mozIStorageConnection::backupDB so user data is not lost.
*
* ==========
* DANGER
* ==========
*
* If you have more than one connection to a file, you MUST use the EXACT
* SAME NAME for the file each time, including case. The sqlite code uses
* a simple string compare to see if there is already a connection. Opening
* a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
*
* The connection object returned by this function is not threadsafe. You must
* use it only from the thread you created it from.
*
* @param aDatabaseFile
* A nsIFile that represents the database that is to be opened..
*
* @returns a mozIStorageConnection for the requested database file.
*
* @throws NS_ERROR_OUT_OF_MEMORY
* If allocating a new storage object fails.
* @throws NS_ERROR_FILE_CORRUPTED
* If the database file is corrupted.
*/
mozIStorageConnection openDatabase(in nsIFile aDatabaseFile);
/**
* Open a connection to the specified file that doesn't share a sqlite cache.
*
* Without a shared-cache, each connection uses its own pages cache, which
* may be memory inefficient with a large number of connections, in such a
* case so you should use openDatabase instead. On the other side, if cache
* contention may be an issue, for instance when concurrency is important to
* ensure responsiveness, using unshared connections may be a performance win.
*
* ==========
* DANGER
* ==========
*
* If you have more than one connection to a file, you MUST use the EXACT
* SAME NAME for the file each time, including case. The sqlite code uses
* a simple string compare to see if there is already a connection. Opening
* a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
*
* The connection object returned by this function is not threadsafe. You must
* use it only from the thread you created it from.
*
* @param aDatabaseFile
* A nsIFile that represents the database that is to be opened.
*
* @returns a mozIStorageConnection for the requested database file.
*
* @throws NS_ERROR_OUT_OF_MEMORY
* If allocating a new storage object fails.
* @throws NS_ERROR_FILE_CORRUPTED
* If the database file is corrupted.
*/
mozIStorageConnection openUnsharedDatabase(in nsIFile aDatabaseFile);
/**
* See openDatabase(). Exactly the same only initialized with a file URL.
* Custom parameters can be passed to SQLite and VFS implementations through
* the query part of the URL.
*
* @param aURL
* A nsIFileURL that represents the database that is to be opened.
*/
mozIStorageConnection openDatabaseWithFileURL(in nsIFileURL aFileURL);
/*
* Utilities
*/
/**
* Copies the specified database file to the specified parent directory with
* the specified file name. If the parent directory is not specified, it
* places the backup in the same directory as the current file. This function
* ensures that the file being created is unique.
*
* @param aDBFile
* The database file that will be backed up.
* @param aBackupFileName
* The name of the new backup file to create.
* @param [optional] aBackupParentDirectory
* The directory you'd like the backup file to be placed.
* @return The nsIFile representing the backup file.
*/
nsIFile backupDatabaseFile(in nsIFile aDBFile, in AString aBackupFileName,
[optional] in nsIFile aBackupParentDirectory);
};
%{C++
#define MOZ_STORAGE_MEMORY_STORAGE_KEY "memory"
%}