storage/mozIStorageAsyncConnection.idl
author Nathan Froyd <froydnj@mozilla.com>
Wed, 03 Apr 2019 00:06:04 +0000
changeset 467750 1b9e5f4b0589a636233affb84666a469a4cc4ef5
parent 465883 cfd44c936a9b52dc094321ac20a4422ef5b12282
child 474571 63d2eaf71d022b0fdaca6f12ca8ec4219d46f4c7
permissions -rw-r--r--
Bug 1537643 - update cc crate; r=glandium This update from the official sources brings in the changes that we were using glandium's fork for, as well as changes enabling us to tweak more settings on Windows. Differential Revision: https://phabricator.services.mozilla.com/D25888

/* -*- 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 mozIStorageAggregateFunction;
interface mozIStorageCompletionCallback;
interface mozIStorageFunction;
interface mozIStorageProgressHandler;
interface mozIStorageBaseStatement;
interface mozIStorageStatement;
interface mozIStorageAsyncStatement;
interface mozIStorageStatementCallback;
interface mozIStoragePendingStatement;
interface nsIFile;

/**
 * mozIStorageAsyncConnection represents an asynchronous database
 * connection attached to a specific file or to an in-memory data
 * storage.  It is the primary interface for interacting with a
 * database from the main thread, including creating prepared
 * statements, executing SQL, and examining database errors.
 */
[scriptable, uuid(8bfd34d5-4ddf-4e4b-89dd-9b14f33534c6)]
interface mozIStorageAsyncConnection : nsISupports {
  /**
   * Transaction behavior constants.
   */
  const int32_t TRANSACTION_DEFAULT = -1;
  const int32_t TRANSACTION_DEFERRED = 0;
  const int32_t TRANSACTION_IMMEDIATE = 1;
  const int32_t TRANSACTION_EXCLUSIVE = 2;

  /**
   * The default behavior for all transactions run on this connection. Defaults
   * to `TRANSACTION_DEFERRED`, and can be overridden for individual
   * transactions.
   */
  attribute int32_t defaultTransactionType;

  /**
   * Close this database connection, allowing all pending statements
   * to complete first.
   *
   * @param aCallback [optional]
   *        A callback that will be notified when the close is completed,
   *        with the following arguments:
   *        - status: the status of the call
   *        - value: |null|
   *
   * @throws NS_ERROR_NOT_SAME_THREAD
   *         If called on a thread other than the one that opened it.  The
   *         callback will not be dispatched.
   * @throws NS_ERROR_NOT_INITIALIZED
   *         If called on a connection that has already been closed or was
   *         never properly opened.  The callback will still be dispatched
   *         to the main thread despite the returned error.
   * @note If this call should fail, the callback won't be invoked.
   */
  void asyncClose([optional] in mozIStorageCompletionCallback aCallback);

  /**
   * Forcibly closes a database connection synchronously.
   * This should only be used when it's required to close and replace the
   * database synchronously to return control to the consumer, for example in
   * case of a detected corruption on database opening.
   * Since this spins the events loop, it should be used only in very particular
   * and rare situations, or it may cause unexpected consequences (crashes).
   *
   * @throws NS_ERROR_NOT_SAME_THREAD
   *         If called on a thread other than the one that opened it.
   */
  [noscript] void spinningSynchronousClose();

  /**
   * Clone a database and make the clone read only if needed.
   * SQL Functions and attached on-disk databases are applied to the new clone.
   *
   * @param aReadOnly
   *        If true, the returned database should be put into read-only mode.
   *
   * @param aCallback
   *        A callback that will be notified when the operation is complete,
   *        with the following arguments:
   *        - status: the status of the operation
   *        - value: in case of success, an intance of
   *             mozIStorageAsyncConnection cloned from this one.
   *
   * @throws NS_ERROR_NOT_SAME_THREAD
   *         If is called on a thread other than the one that opened it.
   * @throws NS_ERROR_UNEXPECTED
   *         If this connection is a memory database.
   *
   * @note If your connection is already read-only, you will get a read-only
   *       clone.
   * @note The resulting connection will implement `mozIStorageConnection`, but
   *       all synchronous methods will throw if called from the main thread.
   * @note Due to a bug in SQLite, if you use the shared cache
   *       (see mozIStorageService), you end up with the same privileges as the
   *       first connection opened regardless of what is specified in aReadOnly.
   * @note The following pragmas are copied over to a read-only clone:
   *        - cache_size
   *        - temp_store
   *       The following pragmas are copied over to a writeable clone:
   *        - cache_size
   *        - temp_store
   *        - foreign_keys
   *        - journal_size_limit
   *        - synchronous
   *        - wal_autocheckpoint
   *       All SQL functions are copied over to read-only and writeable clones.
   *       Additionally, all temporary tables, triggers, and views, as well as
   *       any indexes on temporary tables, are copied over to writeable clones.
   *       For temporary tables, only the schemas are copied, not their
   *       contents.
   */
  void asyncClone(in boolean aReadOnly,
                  in mozIStorageCompletionCallback aCallback);

  /**
   * The current database nsIFile.  Null if the database
   * connection refers to an in-memory database.
   */
  readonly attribute nsIFile databaseFile;

  /**
   * Causes any pending database operation to abort and return at the first
   * opportunity.
   * This can only be used on read-only connections that don't implement
   * the mozIStorageConnection interface.
   * @note operations that are nearly complete may still be able to complete.
   * @throws if used on an unsupported connection type, or a closed connection.
   */
  void interrupt();

  //////////////////////////////////////////////////////////////////////////////
  //// Statement creation

  /**
   * Create an asynchronous statement for the given SQL. An
   * asynchronous statement can only be used to dispatch asynchronous
   * requests to the asynchronous execution thread and cannot be used
   * to take any synchronous actions on the database.
   *
   * The expression may use ? to indicate sequential numbered arguments,
   * ?1, ?2 etc. to indicate specific numbered arguments or :name and
   * $var to indicate named arguments.
   *
   * @param aSQLStatement
   *        The SQL statement to execute.
   * @return a new mozIStorageAsyncStatement
   * @note The statement is created lazily on first execution.
   */
  mozIStorageAsyncStatement createAsyncStatement(in AUTF8String aSQLStatement);

  /**
   * Execute an array of statements created with this connection using
   * any currently bound parameters. When the array contains multiple
   * statements, the execution is wrapped in a single
   * transaction. These statements can be reused immediately, and
   * reset does not need to be called.
   *
   * @param aStatements
   *        The array of statements to execute asynchronously, in the order they
   *        are given in the array.
   * @param aNumStatements
   *        The number of statements in aStatements.
   * @param aCallback [optional]
   *        The callback object that will be notified of progress, errors, and
   *        completion.
   * @return an object that can be used to cancel the statements execution.
   *
   * @note If you have any custom defined functions, they must be
   *        re-entrant since they can be called on multiple threads.
   */
  mozIStoragePendingStatement executeAsync(
    [array, size_is(aNumStatements)] in mozIStorageBaseStatement aStatements,
    in unsigned long aNumStatements,
    [optional] in mozIStorageStatementCallback aCallback
  );

  /**
   * Execute asynchronously an SQL expression, expecting no arguments.
   *
   * @param aSQLStatement
   *        The SQL statement to execute
   * @param aCallback [optional]
   *        The callback object that will be notified of progress, errors, and
   *        completion.
   * @return an object that can be used to cancel the statement execution.
   */
  mozIStoragePendingStatement executeSimpleSQLAsync(
    in AUTF8String aSQLStatement,
    [optional] in mozIStorageStatementCallback aCallback);

  //////////////////////////////////////////////////////////////////////////////
  //// Functions

  /**
   * Create a new SQL function.  If you use your connection on multiple threads,
   * your function needs to be threadsafe, or it should only be called on one
   * thread.
   *
   * @param aFunctionName
   *        The name of function to create, as seen in SQL.
   * @param aNumArguments
   *        The number of arguments the function takes. Pass -1 for
   *        variable-argument functions.
   * @param aFunction
   *        The instance of mozIStorageFunction, which implements the function
   *        in question.
   */
  void createFunction(in AUTF8String aFunctionName,
                      in long aNumArguments,
                      in mozIStorageFunction aFunction);

  /**
   * Create a new SQL aggregate function.  If you use your connection on
   * multiple threads, your function needs to be threadsafe, or it should only
   * be called on one thread.
   *
   * @param aFunctionName
   *        The name of aggregate function to create, as seen in SQL.
   * @param aNumArguments
   *        The number of arguments the function takes. Pass -1 for
   *        variable-argument functions.
   * @param aFunction
   *        The instance of mozIStorageAggreagteFunction, which implements the
   *        function in question.
   */
  void createAggregateFunction(in AUTF8String aFunctionName,
                               in long aNumArguments,
                               in mozIStorageAggregateFunction aFunction);
  /**
   * Delete custom SQL function (simple or aggregate one).
   *
   * @param aFunctionName
   *        The name of function to remove.
   */
  void removeFunction(in AUTF8String aFunctionName);

  /**
   * Sets a progress handler. Only one handler can be registered at a time.
   * If you need more than one, you need to chain them yourself.  This progress
   * handler should be threadsafe if you use this connection object on more than
   * one thread.
   *
   * @param aGranularity
   *        The number of SQL virtual machine steps between progress handler
   *        callbacks.
   * @param aHandler
   *        The instance of mozIStorageProgressHandler.
   * @return previous registered handler.
   */
  mozIStorageProgressHandler setProgressHandler(in int32_t aGranularity,
                                                in mozIStorageProgressHandler aHandler);

  /**
   * Remove a progress handler.
   *
   * @return previous registered handler.
   */
  mozIStorageProgressHandler removeProgressHandler();
};