/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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"
/**
* This interface provides a mechanism to control an output stream
* that takes care not to overwrite an existing target until it is known
* that all writes to the destination succeeded.
*
* An object that supports this interface is intended to also support
* nsIOutputStream.
*
* For example, a file output stream that supports this interface writes to
* a temporary file, and moves it over the original file when |finish| is
* called only if the stream can be successfully closed and all writes
* succeeded. If |finish| is called but something went wrong during
* writing, it will delete the temporary file and not touch the original.
* If the stream is closed by calling |close| directly, or the stream
* goes away, the original file will not be overwritten, and the temporary
* file will be deleted.
*
* Currently, this interface is implemented only for file output streams.
*/
[scriptable, uuid(5f914307-5c34-4e1f-8e32-ec749d25b27a)]
interface nsISafeOutputStream : nsISupports
{
/**
* Call this method to close the stream and cause the original target
* to be overwritten. Note: if any call to |write| failed to write out
* all of the data given to it, then calling this method will |close| the
* stream and return failure. Further, if closing the stream fails, this
* method will return failure. The original target will be overwritten only
* if all calls to |write| succeeded and the stream was successfully closed.
*/
void finish();
};
