storage/mozIStorageService.idl

   1 /* -*- Mode: idl; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsISupports.idl"
   7
   8 interface mozIStorageConnection;
   9 interface nsIFile;
  10 interface nsIFileURL;
  11 interface nsIPropertyBag2;
  12 interface nsIVariant;
  13 interface mozIStorageCompletionCallback;
  14
  15 /**
  16  * The mozIStorageService interface is intended to be implemented by
  17  * a service that can create storage connections (mozIStorageConnection)
  18  * to either a well-known profile database or to a specific database file.
  19  *
  20  * This is the only way to open a database connection.
  21  *
  22  * @note The first reference to mozIStorageService must be made on the main
  23  * thread.
  24  */
  25 [scriptable, uuid(07b6b2f5-6d97-47b4-9584-e65bc467fe9e)]
  26 interface mozIStorageService : nsISupports {
  27   /**
  28    * Open an asynchronous connection to a database.
  29    *
  30    * This method MUST be called from the main thread. The connection object
  31    * returned by this function is not threadsafe. You MUST use it only from
  32    * the main thread.
  33    *
  34    * If you have more than one connection to a file, you MUST use the EXACT
  35    * SAME NAME for the file each time, including case. The sqlite code uses
  36    * a simple string compare to see if there is already a connection. Opening
  37    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
  38    *
  39    * @param aDatabaseStore Either a nsIFile representing the file that contains
  40    * the database or a special string to open a special database. The special
  41    * string may be:
  42    * - "memory" to open an in-memory database.
  43    *
  44    * @param aOptions A set of options (may be null). Options may contain:
  45    * - bool shared (defaults to |false|).
  46    *   -- If |true|, opens the database with a shared-cache. The
  47    *     shared-cache mode is more memory-efficient when many
  48    *     connections to the same database are expected, though, the
  49    *     connections will contend the cache resource. In any cases
  50    *     where performance matter, working without a shared-cache will
  51    *     improve concurrency.  @see openUnsharedDatabase
  52    *
  53    * - int growthIncrement (defaults to none).
  54    *   -- Set the growth increment for the main database.  This hints SQLite to
  55    *      grow the database file by a given chunk size and may reduce
  56    *      filesystem fragmentation on large databases.
  57    *      @see mozIStorageConnection::setGrowthIncrement
  58    *
  59    * @param aCallback A callback that will receive the result of the operation.
  60    *  In case of error, it may receive as status:
  61    *  - NS_ERROR_OUT_OF_MEMORY if allocating a new storage object fails.
  62    *  - NS_ERROR_FILE_CORRUPTED if the database file is corrupted.
  63    *  In case of success, it receives as argument the new database
  64    *  connection, as an instance of |mozIStorageAsyncConnection|.
  65    *
  66    * @throws NS_ERROR_INVALID_ARG if |aDatabaseStore| is neither a file nor
  67    *         one of the special strings understood by this method, or if one of
  68    *         the options passed through |aOptions| does not have the right type.
  69    * @throws NS_ERROR_NOT_SAME_THREAD if called from a thread other than the
  70    *         main thread.
  71    */
  72   void openAsyncDatabase(in nsIVariant aDatabaseStore,
  73                          [optional] in nsIPropertyBag2 aOptions,
  74                          in mozIStorageCompletionCallback aCallback);
  75   /**
  76    * Get a connection to a named special database storage.
  77    *
  78    * @param aStorageKey a string key identifying the type of storage
  79    * requested.  Valid values include: "memory".
  80    *
  81    * @see openDatabase for restrictions on how database connections may be
  82    * used. For the profile database, you should only access it from the main
  83    * thread since other callers may also have connections.
  84    *
  85    * @returns a new mozIStorageConnection for the requested
  86    * storage database.
  87    *
  88    * @throws NS_ERROR_INVALID_ARG if aStorageKey is invalid.
  89    */
  90   mozIStorageConnection openSpecialDatabase(in string aStorageKey);
  91
  92   /**
  93    * Open a connection to the specified file.
  94    *
  95    * Consumers should check mozIStorageConnection::connectionReady to ensure
  96    * that they can use the database.  If this value is false, it is strongly
  97    * recommended that the database be backed up with
  98    * mozIStorageConnection::backupDB so user data is not lost.
  99    *
 100    * ==========
 101    *   DANGER
 102    * ==========
 103    *
 104    * If you have more than one connection to a file, you MUST use the EXACT
 105    * SAME NAME for the file each time, including case. The sqlite code uses
 106    * a simple string compare to see if there is already a connection. Opening
 107    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
 108    *
 109    * The connection object returned by this function is not threadsafe. You must
 110    * use it only from the thread you created it from.
 111    *
 112    * @param aDatabaseFile
 113    *        A nsIFile that represents the database that is to be opened..
 114    *
 115    * @returns a mozIStorageConnection for the requested database file.
 116    *
 117    * @throws NS_ERROR_OUT_OF_MEMORY
 118    *         If allocating a new storage object fails.
 119    * @throws NS_ERROR_FILE_CORRUPTED
 120    *         If the database file is corrupted.
 121    */
 122   mozIStorageConnection openDatabase(in nsIFile aDatabaseFile);
 123
 124   /**
 125    * Open a connection to the specified file that doesn't share a sqlite cache.
 126    *
 127    * Without a shared-cache, each connection uses its own pages cache, which
 128    * may be memory inefficient with a large number of connections, in such a
 129    * case so you should use openDatabase instead.  On the other side, if cache
 130    * contention may be an issue, for instance when concurrency is important to
 131    * ensure responsiveness, using unshared connections may be a performance win.
 132    *
 133    * ==========
 134    *   DANGER
 135    * ==========
 136    *
 137    * If you have more than one connection to a file, you MUST use the EXACT
 138    * SAME NAME for the file each time, including case. The sqlite code uses
 139    * a simple string compare to see if there is already a connection. Opening
 140    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
 141    *
 142    * The connection object returned by this function is not threadsafe. You must
 143    * use it only from the thread you created it from.
 144    *
 145    * @param aDatabaseFile
 146    *        A nsIFile that represents the database that is to be opened.
 147    *
 148    * @returns a mozIStorageConnection for the requested database file.
 149    *
 150    * @throws NS_ERROR_OUT_OF_MEMORY
 151    *         If allocating a new storage object fails.
 152    * @throws NS_ERROR_FILE_CORRUPTED
 153    *         If the database file is corrupted.
 154    */
 155   mozIStorageConnection openUnsharedDatabase(in nsIFile aDatabaseFile);
 156
 157   /**
 158    * See openDatabase(). Exactly the same only initialized with a file URL.
 159    * Custom parameters can be passed to SQLite and VFS implementations through
 160    * the query part of the URL.
 161    *
 162    * @param aURL
 163    *        A nsIFileURL that represents the database that is to be opened.
 164    */
 165   mozIStorageConnection openDatabaseWithFileURL(in nsIFileURL aFileURL);
 166
 167   /*
 168    * Utilities
 169    */
 170
 171   /**
 172    * Copies the specified database file to the specified parent directory with
 173    * the specified file name.  If the parent directory is not specified, it
 174    * places the backup in the same directory as the current file.  This function
 175    * ensures that the file being created is unique.
 176    *
 177    * @param aDBFile
 178    *        The database file that will be backed up.
 179    * @param aBackupFileName
 180    *        The name of the new backup file to create.
 181    * @param [optional] aBackupParentDirectory
 182    *        The directory you'd like the backup file to be placed.
 183    * @return The nsIFile representing the backup file.
 184    */
 185   nsIFile backupDatabaseFile(in nsIFile aDBFile, in AString aBackupFileName,
 186                              [optional] in nsIFile aBackupParentDirectory);
 187 };
 188
 189 %{C++
 190
 191 #define MOZ_STORAGE_MEMORY_STORAGE_KEY    "memory"
 192
 193 %}