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 %{C++
   9
  10 #include "nsLiteralString.h"
  11
  12 %}
  13
  14 interface mozIStorageConnection;
  15 interface nsIFile;
  16 interface nsIFileURL;
  17 interface nsIPropertyBag2;
  18 interface nsIVariant;
  19 interface mozIStorageCompletionCallback;
  20
  21 /**
  22  * The mozIStorageService interface is intended to be implemented by
  23  * a service that can create storage connections (mozIStorageConnection)
  24  * to either a well-known profile database or to a specific database file.
  25  *
  26  * This is the only way to open a database connection.
  27  *
  28  * @note The first reference to mozIStorageService must be made on the main
  29  * thread.
  30  */
  31 [scriptable, uuid(07b6b2f5-6d97-47b4-9584-e65bc467fe9e)]
  32 interface mozIStorageService : nsISupports {
  33   /**
  34    * Open an asynchronous connection to a database.
  35    *
  36    * This method MUST be called from the main thread. The connection object
  37    * returned by this function is not threadsafe. You MUST use it only from
  38    * the main thread.
  39    *
  40    * If you have more than one connection to a file, you MUST use the EXACT
  41    * SAME NAME for the file each time, including case. The sqlite code uses
  42    * a simple string compare to see if there is already a connection. Opening
  43    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
  44    *
  45    * @param aDatabaseStore Either a nsIFile representing the file that contains
  46    * the database or a special string to open a special database. The special
  47    * string may be:
  48    * - "memory" to open an in-memory database.
  49    *
  50    * @param aOptions A set of options (may be null). Options may contain:
  51    * - bool shared (defaults to |false|).
  52    *   -- If |true|, opens the database with a shared-cache. The
  53    *     shared-cache mode is more memory-efficient when many
  54    *     connections to the same database are expected, though, the
  55    *     connections will contend the cache resource. In any cases
  56    *     where performance matter, working without a shared-cache will
  57    *     improve concurrency.  @see openUnsharedDatabase
  58    *
  59    * - int growthIncrement (defaults to none).
  60    *   -- Set the growth increment for the main database.  This hints SQLite to
  61    *      grow the database file by a given chunk size and may reduce
  62    *      filesystem fragmentation on large databases.
  63    *      @see mozIStorageConnection::setGrowthIncrement
  64    *
  65    * @param aCallback A callback that will receive the result of the operation.
  66    *  In case of error, it may receive as status:
  67    *  - NS_ERROR_OUT_OF_MEMORY if allocating a new storage object fails.
  68    *  - NS_ERROR_FILE_CORRUPTED if the database file is corrupted.
  69    *  In case of success, it receives as argument the new database
  70    *  connection, as an instance of |mozIStorageAsyncConnection|.
  71    *
  72    * @throws NS_ERROR_INVALID_ARG if |aDatabaseStore| is neither a file nor
  73    *         one of the special strings understood by this method, or if one of
  74    *         the options passed through |aOptions| does not have the right type.
  75    * @throws NS_ERROR_NOT_SAME_THREAD if called from a thread other than the
  76    *         main thread.
  77    */
  78   void openAsyncDatabase(in nsIVariant aDatabaseStore,
  79                          [optional] in nsIPropertyBag2 aOptions,
  80                          in mozIStorageCompletionCallback aCallback);
  81   /**
  82    * Get a connection to a named special database storage.
  83    *
  84    * @param aStorageKey a string key identifying the type of storage
  85    * requested.  Valid values include: "memory".
  86    *
  87    * @param aName an optional string identifying the name of the database.
  88    * If omitted, a filename of ":memory:" will be used which results in a
  89    * private in-memory database specific to this connection, making it
  90    * impossible to clone the in-memory database. If you want to be able to
  91    * clone the connection (or otherwise connect to the in-memory database from
  92    * a connection), then you must pick a name that's sufficiently unique within
  93    * the process to not collide with other mozStorage users.
  94    *
  95    * @see openDatabase for restrictions on how database connections may be
  96    * used. For the profile database, you should only access it from the main
  97    * thread since other callers may also have connections.
  98    *
  99    * @returns a new mozIStorageConnection for the requested
 100    * storage database.
 101    *
 102    * @throws NS_ERROR_INVALID_ARG if aStorageKey is invalid.
 103    */
 104   mozIStorageConnection openSpecialDatabase(in ACString aStorageKey,
 105                                             [optional] in ACString aName);
 106
 107   /**
 108    * Open a connection to the specified file.
 109    *
 110    * Consumers should check mozIStorageConnection::connectionReady to ensure
 111    * that they can use the database.  If this value is false, it is strongly
 112    * recommended that the database be backed up with
 113    * mozIStorageConnection::backupDB so user data is not lost.
 114    *
 115    * ==========
 116    *   DANGER
 117    * ==========
 118    *
 119    * If you have more than one connection to a file, you MUST use the EXACT
 120    * SAME NAME for the file each time, including case. The sqlite code uses
 121    * a simple string compare to see if there is already a connection. Opening
 122    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
 123    *
 124    * The connection object returned by this function is not threadsafe. You must
 125    * use it only from the thread you created it from.
 126    *
 127    * @param aDatabaseFile
 128    *        A nsIFile that represents the database that is to be opened..
 129    *
 130    * @returns a mozIStorageConnection for the requested database file.
 131    *
 132    * @throws NS_ERROR_OUT_OF_MEMORY
 133    *         If allocating a new storage object fails.
 134    * @throws NS_ERROR_FILE_CORRUPTED
 135    *         If the database file is corrupted.
 136    */
 137   mozIStorageConnection openDatabase(in nsIFile aDatabaseFile);
 138
 139   /**
 140    * Open a connection to the specified file that doesn't share a sqlite cache.
 141    *
 142    * Without a shared-cache, each connection uses its own pages cache, which
 143    * may be memory inefficient with a large number of connections, in such a
 144    * case so you should use openDatabase instead.  On the other side, if cache
 145    * contention may be an issue, for instance when concurrency is important to
 146    * ensure responsiveness, using unshared connections may be a performance win.
 147    *
 148    * ==========
 149    *   DANGER
 150    * ==========
 151    *
 152    * If you have more than one connection to a file, you MUST use the EXACT
 153    * SAME NAME for the file each time, including case. The sqlite code uses
 154    * a simple string compare to see if there is already a connection. Opening
 155    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
 156    *
 157    * The connection object returned by this function is not threadsafe. You must
 158    * use it only from the thread you created it from.
 159    *
 160    * @param aDatabaseFile
 161    *        A nsIFile that represents the database that is to be opened.
 162    *
 163    * @returns a mozIStorageConnection for the requested database file.
 164    *
 165    * @throws NS_ERROR_OUT_OF_MEMORY
 166    *         If allocating a new storage object fails.
 167    * @throws NS_ERROR_FILE_CORRUPTED
 168    *         If the database file is corrupted.
 169    */
 170   mozIStorageConnection openUnsharedDatabase(in nsIFile aDatabaseFile);
 171
 172   /**
 173    * See openDatabase(). Exactly the same only initialized with a file URL.
 174    * Custom parameters can be passed to SQLite and VFS implementations through
 175    * the query part of the URL.
 176    *
 177    * @param aURL
 178    *        A nsIFileURL that represents the database that is to be opened.
 179    * @param [optional] aTelemetryFilename
 180    *        The name to use for the database in telemetry. Only needed if the
 181    *        actual filename can contain sensitive information.
 182    */
 183   mozIStorageConnection openDatabaseWithFileURL(in nsIFileURL aFileURL,
 184                                                 [optional] in ACString aTelemetryFilename);
 185
 186   /*
 187    * Utilities
 188    */
 189
 190   /**
 191    * Copies the specified database file to the specified parent directory with
 192    * the specified file name.  If the parent directory is not specified, it
 193    * places the backup in the same directory as the current file.  This function
 194    * ensures that the file being created is unique.
 195    *
 196    * @param aDBFile
 197    *        The database file that will be backed up.
 198    * @param aBackupFileName
 199    *        The name of the new backup file to create.
 200    * @param [optional] aBackupParentDirectory
 201    *        The directory you'd like the backup file to be placed.
 202    * @return The nsIFile representing the backup file.
 203    */
 204   nsIFile backupDatabaseFile(in nsIFile aDBFile, in AString aBackupFileName,
 205                              [optional] in nsIFile aBackupParentDirectory);
 206 };
 207
 208 %{C++
 209
 210 constexpr auto kMozStorageMemoryStorageKey = "memory"_ns;
 211
 212 %}