storage/mozIStorageAsyncConnection.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 mozIStorageAggregateFunction;
   9 interface mozIStorageCompletionCallback;
  10 interface mozIStorageFunction;
  11 interface mozIStorageProgressHandler;
  12 interface mozIStorageBaseStatement;
  13 interface mozIStorageStatement;
  14 interface mozIStorageAsyncStatement;
  15 interface mozIStorageStatementCallback;
  16 interface mozIStoragePendingStatement;
  17 interface nsIFile;
  18
  19 /**
  20  * mozIStorageAsyncConnection represents an asynchronous database
  21  * connection attached to a specific file or to an in-memory data
  22  * storage.  It is the primary interface for interacting with a
  23  * database from the main thread, including creating prepared
  24  * statements, executing SQL, and examining database errors.
  25  */
  26 [scriptable, uuid(8bfd34d5-4ddf-4e4b-89dd-9b14f33534c6)]
  27 interface mozIStorageAsyncConnection : nsISupports {
  28   /**
  29    * Transaction behavior constants.
  30    */
  31   const int32_t TRANSACTION_DEFAULT = -1;
  32   const int32_t TRANSACTION_DEFERRED = 0;
  33   const int32_t TRANSACTION_IMMEDIATE = 1;
  34   const int32_t TRANSACTION_EXCLUSIVE = 2;
  35
  36   /**
  37    * The default behavior for all transactions run on this connection. Defaults
  38    * to `TRANSACTION_DEFERRED`, and can be overridden for individual
  39    * transactions.
  40    */
  41   attribute int32_t defaultTransactionType;
  42
  43   /**
  44    * Close this database connection, allowing all pending statements
  45    * to complete first.
  46    *
  47    * @param aCallback [optional]
  48    *        A callback that will be notified when the close is completed,
  49    *        with the following arguments:
  50    *        - status: the status of the call
  51    *        - value: |null|
  52    *
  53    * @throws NS_ERROR_NOT_SAME_THREAD
  54    *         If called on a thread other than the one that opened it.  The
  55    *         callback will not be dispatched.
  56    * @throws NS_ERROR_NOT_INITIALIZED
  57    *         If called on a connection that has already been closed or was
  58    *         never properly opened.  The callback will still be dispatched
  59    *         to the main thread despite the returned error.
  60    * @note If this call should fail, the callback won't be invoked.
  61    */
  62   void asyncClose([optional] in mozIStorageCompletionCallback aCallback);
  63
  64   /**
  65    * Forcibly closes a database connection synchronously.
  66    * This should only be used when it's required to close and replace the
  67    * database synchronously to return control to the consumer, for example in
  68    * case of a detected corruption on database opening.
  69    * Since this spins the events loop, it should be used only in very particular
  70    * and rare situations, or it may cause unexpected consequences (crashes).
  71    *
  72    * @throws NS_ERROR_NOT_SAME_THREAD
  73    *         If called on a thread other than the one that opened it.
  74    */
  75   [noscript] void spinningSynchronousClose();
  76
  77   /**
  78    * Clone a database and make the clone read only if needed.
  79    * SQL Functions and attached on-disk databases are applied to the new clone.
  80    *
  81    * @param aReadOnly
  82    *        If true, the returned database should be put into read-only mode.
  83    *
  84    * @param aCallback
  85    *        A callback that will be notified when the operation is complete,
  86    *        with the following arguments:
  87    *        - status: the status of the operation
  88    *        - value: in case of success, an intance of
  89    *             mozIStorageAsyncConnection cloned from this one.
  90    *
  91    * @throws NS_ERROR_NOT_SAME_THREAD
  92    *         If is called on a thread other than the one that opened it.
  93    * @throws NS_ERROR_UNEXPECTED
  94    *         If this connection is a memory database.
  95    *
  96    * @note If your connection is already read-only, you will get a read-only
  97    *       clone.
  98    * @note The resulting connection will NOT implement mozIStorageConnection,
  99    *       it will only implement mozIStorageAsyncConnection.
 100    * @note Due to a bug in SQLite, if you use the shared cache
 101    *       (see mozIStorageService), you end up with the same privileges as the
 102    *       first connection opened regardless of what is specified in aReadOnly.
 103    * @note The following pragmas are copied over to a read-only clone:
 104    *        - cache_size
 105    *        - temp_store
 106    *       The following pragmas are copied over to a writeable clone:
 107    *        - cache_size
 108    *        - temp_store
 109    *        - foreign_keys
 110    *        - journal_size_limit
 111    *        - synchronous
 112    *        - wal_autocheckpoint
 113    *       All SQL functions are copied over to read-only and writeable clones.
 114    *       Additionally, all temporary tables, triggers, and views, as well as
 115    *       any indexes on temporary tables, are copied over to writeable clones.
 116    *       For temporary tables, only the schemas are copied, not their
 117    *       contents.
 118    */
 119   void asyncClone(in boolean aReadOnly,
 120                   in mozIStorageCompletionCallback aCallback);
 121
 122   /**
 123    * The current database nsIFile.  Null if the database
 124    * connection refers to an in-memory database.
 125    */
 126   readonly attribute nsIFile databaseFile;
 127
 128   /**
 129    * Causes any pending database operation to abort and return at the first
 130    * opportunity.
 131    * This can only be used on read-only connections that don't implement
 132    * the mozIStorageConnection interface.
 133    * @note operations that are nearly complete may still be able to complete.
 134    * @throws if used on an unsupported connection type, or a closed connection.
 135    */
 136   void interrupt();
 137
 138   //////////////////////////////////////////////////////////////////////////////
 139   //// Statement creation
 140
 141   /**
 142    * Create an asynchronous statement for the given SQL. An
 143    * asynchronous statement can only be used to dispatch asynchronous
 144    * requests to the asynchronous execution thread and cannot be used
 145    * to take any synchronous actions on the database.
 146    *
 147    * The expression may use ? to indicate sequential numbered arguments,
 148    * ?1, ?2 etc. to indicate specific numbered arguments or :name and
 149    * $var to indicate named arguments.
 150    *
 151    * @param aSQLStatement
 152    *        The SQL statement to execute.
 153    * @return a new mozIStorageAsyncStatement
 154    * @note The statement is created lazily on first execution.
 155    */
 156   mozIStorageAsyncStatement createAsyncStatement(in AUTF8String aSQLStatement);
 157
 158   /**
 159    * Execute an array of statements created with this connection using
 160    * any currently bound parameters. When the array contains multiple
 161    * statements, the execution is wrapped in a single
 162    * transaction. These statements can be reused immediately, and
 163    * reset does not need to be called.
 164    *
 165    * @param aStatements
 166    *        The array of statements to execute asynchronously, in the order they
 167    *        are given in the array.
 168    * @param aNumStatements
 169    *        The number of statements in aStatements.
 170    * @param aCallback [optional]
 171    *        The callback object that will be notified of progress, errors, and
 172    *        completion.
 173    * @return an object that can be used to cancel the statements execution.
 174    *
 175    * @note If you have any custom defined functions, they must be
 176    *        re-entrant since they can be called on multiple threads.
 177    */
 178   mozIStoragePendingStatement executeAsync(
 179     [array, size_is(aNumStatements)] in mozIStorageBaseStatement aStatements,
 180     in unsigned long aNumStatements,
 181     [optional] in mozIStorageStatementCallback aCallback
 182   );
 183
 184   /**
 185    * Execute asynchronously an SQL expression, expecting no arguments.
 186    *
 187    * @param aSQLStatement
 188    *        The SQL statement to execute
 189    * @param aCallback [optional]
 190    *        The callback object that will be notified of progress, errors, and
 191    *        completion.
 192    * @return an object that can be used to cancel the statement execution.
 193    */
 194   mozIStoragePendingStatement executeSimpleSQLAsync(
 195     in AUTF8String aSQLStatement,
 196     [optional] in mozIStorageStatementCallback aCallback);
 197
 198   //////////////////////////////////////////////////////////////////////////////
 199   //// Functions
 200
 201   /**
 202    * Create a new SQL function.  If you use your connection on multiple threads,
 203    * your function needs to be threadsafe, or it should only be called on one
 204    * thread.
 205    *
 206    * @param aFunctionName
 207    *        The name of function to create, as seen in SQL.
 208    * @param aNumArguments
 209    *        The number of arguments the function takes. Pass -1 for
 210    *        variable-argument functions.
 211    * @param aFunction
 212    *        The instance of mozIStorageFunction, which implements the function
 213    *        in question.
 214    */
 215   void createFunction(in AUTF8String aFunctionName,
 216                       in long aNumArguments,
 217                       in mozIStorageFunction aFunction);
 218
 219   /**
 220    * Create a new SQL aggregate function.  If you use your connection on
 221    * multiple threads, your function needs to be threadsafe, or it should only
 222    * be called on one thread.
 223    *
 224    * @param aFunctionName
 225    *        The name of aggregate function to create, as seen in SQL.
 226    * @param aNumArguments
 227    *        The number of arguments the function takes. Pass -1 for
 228    *        variable-argument functions.
 229    * @param aFunction
 230    *        The instance of mozIStorageAggreagteFunction, which implements the
 231    *        function in question.
 232    */
 233   void createAggregateFunction(in AUTF8String aFunctionName,
 234                                in long aNumArguments,
 235                                in mozIStorageAggregateFunction aFunction);
 236   /**
 237    * Delete custom SQL function (simple or aggregate one).
 238    *
 239    * @param aFunctionName
 240    *        The name of function to remove.
 241    */
 242   void removeFunction(in AUTF8String aFunctionName);
 243
 244   /**
 245    * Sets a progress handler. Only one handler can be registered at a time.
 246    * If you need more than one, you need to chain them yourself.  This progress
 247    * handler should be threadsafe if you use this connection object on more than
 248    * one thread.
 249    *
 250    * @param aGranularity
 251    *        The number of SQL virtual machine steps between progress handler
 252    *        callbacks.
 253    * @param aHandler
 254    *        The instance of mozIStorageProgressHandler.
 255    * @return previous registered handler.
 256    */
 257   mozIStorageProgressHandler setProgressHandler(in int32_t aGranularity,
 258                                                 in mozIStorageProgressHandler aHandler);
 259
 260   /**
 261    * Remove a progress handler.
 262    *
 263    * @return previous registered handler.
 264    */
 265   mozIStorageProgressHandler removeProgressHandler();
 266 };