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 the database with default flags in default mode.
  35    */
  36   const unsigned long OPEN_DEFAULT = 0;
  37
  38   /**
  39    * Open the database with a shared cache. The shared-cache mode
  40    * is more memory-efficient when many connections to the same database
  41    * are expected, though, the connections will contend the cache resource.
  42    * When performance matters, working without a shared-cache will
  43    * improve concurrency.  @see openUnsharedDatabase
  44    */
  45   const unsigned long OPEN_SHARED = 1 << 0;
  46
  47   /**
  48    * Open the underlying database in read-only mode.
  49    */
  50   const unsigned long OPEN_READONLY = 1 << 1;
  51
  52   /**
  53    * Allow simultaneous access to an asynchronous read-only database
  54    * without any file locking.
  55    *
  56    * For synchronous database, the flag has no effect.
  57    *
  58    * Specifying the OPEN_IGNORE_LOCKING_MODE flag will automatically
  59    * turn on the OPEN_READONLY flag.
  60    */
  61   const unsigned long OPEN_IGNORE_LOCKING_MODE = 1 << 2;
  62
  63   /**
  64    * All optional connection object features are off.
  65    */
  66   const unsigned long CONNECTION_DEFAULT = 0;
  67
  68   /**
  69    * Enable Interrupt-method for the synchronous connection object
  70    * returned by openDatabase, openSpecialDatabase, openUnsharedDatabase
  71    * or openDatabaseWithFileURL calls.
  72    *
  73    * When this flag is not set, Interrupt-method of a
  74    * synchronous connection must not be used.
  75    *
  76    * Asynchronous connection is always interruptible and the flag
  77    * does not change anything.
  78    *
  79    * The following are among the potential risks side effects of
  80    * calling the Interrupt-method:
  81    *   - new queries started on a different thread after the
  82    *     interrupt call, but before its completion, are interrupted as if
  83    *     they had been running prior to the interrupt call. Thus thread
  84    *     synchronization is necessary.
  85    *   - calls to close the database will wait until the interruption
  86    *     finishes.
  87    */
  88   const unsigned long CONNECTION_INTERRUPTIBLE = 1 << 0;
  89
  90   /**
  91    * Open an asynchronous connection to a database.
  92    *
  93    * This method MUST be called from the main thread. The connection object
  94    * returned by this function is not threadsafe. You MUST use it only from
  95    * the main thread.
  96    *
  97    * If you have more than one connection to a file, you MUST use the EXACT
  98    * SAME NAME for the file each time, including case. The sqlite code uses
  99    * a simple string compare to see if there is already a connection. Opening
 100    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
 101    *
 102    * @param aDatabaseStore Either a nsIFile representing the file that contains
 103    * the database or a special string to open a special database. The special
 104    * string may be:
 105    * - "memory" to open an in-memory database.
 106    *
 107    * @param [optional] aOpenFlags
 108    *        A set of flags to open the database with optional features.
 109    *        Currently supports OPEN_SHARED, OPEN_READONLY and
 110    *        OPEN_IGNORE_LOCKING_MODE flags.
 111    *        For full details, please refer to the documentation of the flags.
 112    *
 113    * @param [optional] aConnectionFlags
 114    *        A set of flags to enable optional features for the returned
 115    *        asynchronous connection object.
 116    *        Currently supports CONNECTION_INTERRUPTIBLE flag.
 117    *        For full details, please refer to the documentation of the flag.
 118    *
 119    * @param aCallback A callback that will receive the result of the operation.
 120    *  In case of error, it may receive as status:
 121    *  - NS_ERROR_OUT_OF_MEMORY if allocating a new storage object fails.
 122    *  - NS_ERROR_FILE_CORRUPTED if the database file is corrupted.
 123    *  In case of success, it receives as argument the new database
 124    *  connection, as an instance of |mozIStorageAsyncConnection|.
 125    *
 126    * @throws NS_ERROR_INVALID_ARG if |aDatabaseStore| is neither a file nor
 127    *         one of the special strings understood by this method, or if one of
 128    *         the options passed through |aOptions| does not have
 129    *         the right type.
 130    * @throws NS_ERROR_NOT_SAME_THREAD if called from a thread other than the
 131    *         main thread.
 132    */
 133   void openAsyncDatabase(in nsIVariant aDatabaseStore,
 134                          [optional] in unsigned long aOpenFlags,
 135                          [optional] in unsigned long aConnectionFlags,
 136                          in mozIStorageCompletionCallback aCallback);
 137
 138   /**
 139    * Get a connection to a named special database storage.
 140    *
 141    * @param aStorageKey a string key identifying the type of storage
 142    * requested.  Valid values include: "memory".
 143    *
 144    * @param aName an optional string identifying the name of the database.
 145    * If omitted, a filename of ":memory:" will be used which results in a
 146    * private in-memory database specific to this connection, making it
 147    * impossible to clone the in-memory database. If you want to be able to
 148    * clone the connection (or otherwise connect to the in-memory database from
 149    * a connection), then you must pick a name that's sufficiently unique within
 150    * the process to not collide with other mozStorage users.
 151    *
 152    * @param [optional] aConnectionFlags
 153    *        A set of flags to enable optional features for the returned
 154    *        synchronous connection object.
 155    *        Currently supports CONNECTION_INTERRUPTIBLE flag.
 156    *        For full details, please refer to the documentation of the flag.
 157    *
 158    * @see openDatabase for restrictions on how database connections may be
 159    * used. For the profile database, you should only access it from the main
 160    * thread since other callers may also have connections.
 161    *
 162    * @returns a new mozIStorageConnection for the requested
 163    * storage database.
 164    *
 165    * @throws NS_ERROR_INVALID_ARG if aStorageKey is invalid.
 166    */
 167   mozIStorageConnection openSpecialDatabase(
 168       in ACString aStorageKey,
 169       [optional] in ACString aName,
 170       [optional] in unsigned long aConnectionFlags);
 171
 172   /**
 173    * Open a connection to the specified file.
 174    *
 175    * Consumers should check mozIStorageConnection::connectionReady to ensure
 176    * that they can use the database.  If this value is false, it is strongly
 177    * recommended that the database be backed up with
 178    * mozIStorageConnection::backupDB so user data is not lost.
 179    *
 180    * ==========
 181    *   DANGER
 182    * ==========
 183    *
 184    * If you have more than one connection to a file, you MUST use the EXACT
 185    * SAME NAME for the file each time, including case. The sqlite code uses
 186    * a simple string compare to see if there is already a connection. Opening
 187    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
 188    *
 189    * The connection object returned by this function is not threadsafe. You
 190    * must use it only from the thread you created it from.
 191    *
 192    * @param aDatabaseFile
 193    *        A nsIFile that represents the database that is to be opened.
 194    * @param [optional] aConnectionFlags
 195    *        A set of flags to enable optional features for the returned
 196    *        synchronous connection object.
 197    *        Currently supports CONNECTION_INTERRUPTIBLE flag.
 198    *        For full details, please refer to the documentation of the flag.
 199    *
 200    * @returns a mozIStorageConnection for the requested database file.
 201    *
 202    * @throws NS_ERROR_OUT_OF_MEMORY
 203    *         If allocating a new storage object fails.
 204    * @throws NS_ERROR_FILE_CORRUPTED
 205    *         If the database file is corrupted.
 206    */
 207   mozIStorageConnection openDatabase(
 208       in nsIFile aDatabaseFile, [optional] in unsigned long aConnectionFlags);
 209
 210   /**
 211    * Open a connection to the specified file that doesn't share a sqlite cache.
 212    *
 213    * Without a shared-cache, each connection uses its own pages cache, which
 214    * may be memory inefficient with a large number of connections, in such a
 215    * case so you should use openDatabase instead.  On the other side, if cache
 216    * contention may be an issue, for instance when concurrency is important to
 217    * ensure responsiveness, using unshared connections may be a
 218    * performance win.
 219    *
 220    * ==========
 221    *   DANGER
 222    * ==========
 223    *
 224    * If you have more than one connection to a file, you MUST use the EXACT
 225    * SAME NAME for the file each time, including case. The sqlite code uses
 226    * a simple string compare to see if there is already a connection. Opening
 227    * a connection to "Foo.sqlite" and "foo.sqlite" will CORRUPT YOUR DATABASE.
 228    *
 229    * The connection object returned by this function is not threadsafe. You
 230    * must use it only from the thread you created it from.
 231    *
 232    * @param aDatabaseFile
 233    *        A nsIFile that represents the database that is to be opened.
 234    * @param [optional] aConnectionFlags
 235    *        A set of flags to enable optional features for the returned
 236    *        synchronous connection object.
 237    *        Currently supports CONNECTION_INTERRUPTIBLE flag.
 238    *        For full details, please refer to the documentation of the flag.
 239    *
 240    * @returns a mozIStorageConnection for the requested database file.
 241    *
 242    * @throws NS_ERROR_OUT_OF_MEMORY
 243    *         If allocating a new storage object fails.
 244    * @throws NS_ERROR_FILE_CORRUPTED
 245    *         If the database file is corrupted.
 246    */
 247   mozIStorageConnection openUnsharedDatabase(
 248       in nsIFile aDatabaseFile, [optional] in unsigned long aConnectionFlags);
 249
 250   /**
 251    * See openDatabase(). Exactly the same only initialized with a file URL.
 252    * Custom parameters can be passed to SQLite and VFS implementations through
 253    * the query part of the URL.
 254    *
 255    * @param aURL
 256    *        A nsIFileURL that represents the database that is to be opened.
 257    * @param [optional] aTelemetryFilename
 258    *        The name to use for the database in telemetry. Only needed if the
 259    *        actual filename can contain sensitive information.
 260    * @param [optional] aConnectionFlags
 261    *        A set of flags to enable optional features for the returned
 262    *        synchronous connection object.
 263    *        Currently supports CONNECTION_INTERRUPTIBLE flag.
 264    *        For full details, please refer to the documentation of the flag.
 265    */
 266   mozIStorageConnection openDatabaseWithFileURL(
 267       in nsIFileURL aFileURL, [optional] in ACString aTelemetryFilename,
 268       [optional] in unsigned long aConnectionFlags);
 269
 270   /*
 271    * Utilities
 272    */
 273
 274   /**
 275    * Copies the specified database file to the specified parent directory with
 276    * the specified file name.  If the parent directory is not specified, it
 277    * places the backup in the same directory as the current file.  This
 278    * function ensures that the file being created is unique.
 279    *
 280    * @param aDBFile
 281    *        The database file that will be backed up.
 282    * @param aBackupFileName
 283    *        The name of the new backup file to create.
 284    * @param [optional] aBackupParentDirectory
 285    *        The directory you'd like the backup file to be placed.
 286    * @return The nsIFile representing the backup file.
 287    */
 288   nsIFile backupDatabaseFile(in nsIFile aDBFile, in AString aBackupFileName,
 289                              [optional] in nsIFile aBackupParentDirectory);
 290 };
 291
 292 %{C++
 293
 294 constexpr auto kMozStorageMemoryStorageKey = "memory"_ns;
 295
 296 %}