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- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 2002
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- * Darin Fisher <darin@netscape.com>
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
- #include "nsIInputStream.idl"
-
- interface nsIInputStreamCallback;
- interface nsIEventTarget;
-
- /**
- * If an input stream is non-blocking, it may return NS_BASE_STREAM_WOULD_BLOCK
- * when read. The caller must then wait for the stream to have some data to
- * read. If the stream implements nsIAsyncInputStream, then the caller can use
- * this interface to request an asynchronous notification when the stream
- * becomes readable or closed (via the AsyncWait method).
- *
- * While this interface is almost exclusively used with non-blocking streams, it
- * is not necessary that nsIInputStream::isNonBlocking return true. Nor is it
- * necessary that a non-blocking nsIInputStream implementation also implement
- * nsIAsyncInputStream.
- */
- [scriptable, uuid(15a15329-00de-44e8-ab06-0d0b0d43dc5b)]
- interface nsIAsyncInputStream : nsIInputStream
- {
- /**
- * This method closes the stream and sets its internal status. If the
- * stream is already closed, then this method is ignored. Once the stream
- * is closed, the stream's status cannot be changed. Any successful status
- * code passed to this method is treated as NS_BASE_STREAM_CLOSED, which
- * has an effect equivalent to nsIInputStream::close.
- *
- * NOTE: this method exists in part to support pipes, which have both an
- * input end and an output end. If the input end of a pipe is closed, then
- * writes to the output end of the pipe will fail. The error code returned
- * when an attempt is made to write to a "broken" pipe corresponds to the
- * status code passed in when the input end of the pipe was closed, which
- * greatly simplifies working with pipes in some cases.
- *
- * @param aStatus
- * The error that will be reported if this stream is accessed after
- * it has been closed.
- */
- void closeWithStatus(in nsresult aStatus);
-
- /**
- * Asynchronously wait for the stream to be readable or closed. The
- * notification is one-shot, meaning that each asyncWait call will result
- * in exactly one notification callback. After the OnInputStreamReady event
- * is dispatched, the stream releases its reference to the
- * nsIInputStreamCallback object. It is safe to call asyncWait again from the
- * notification handler.
- *
- * This method may be called at any time (even if read has not been called).
- * In other words, this method may be called when the stream already has
- * data to read. It may also be called when the stream is closed. If the
- * stream is already readable or closed when AsyncWait is called, then the
- * OnInputStreamReady event will be dispatched immediately. Otherwise, the
- * event will be dispatched when the stream becomes readable or closed.
- *
- * @param aCallback
- * This object is notified when the stream becomes ready.
- * @param aFlags
- * This parameter specifies optional flags passed in to configure
- * the behavior of this method. Pass zero to specify no flags.
- * @param aRequestedCount
- * Wait until at least this many bytes can be read. This is only
- * a suggestion to the underlying stream; it may be ignored. The
- * caller may pass zero to indicate no preference.
- * @param aEventTarget
- * Specify NULL to receive notification on ANY thread (possibly even
- * recursively on the calling thread -- i.e., synchronously), or
- * specify that the notification be delivered to a specific event
- * target.
- */
- void asyncWait(in nsIInputStreamCallback aCallback,
- in unsigned long aFlags,
- in unsigned long aRequestedCount,
- in nsIEventTarget aEventTarget);
-
- /**
- * If passed to asyncWait, this flag overrides the default behavior,
- * causing the OnInputStreamReady notification to be suppressed until the
- * stream becomes closed (either as a result of closeWithStatus/close being
- * called on the stream or possibly due to some error in the underlying
- * stream).
- */
- const unsigned long WAIT_CLOSURE_ONLY = (1<<0);
- };
-
- /**
- * This is a companion interface for nsIAsyncInputStream::asyncWait.
- */
- [scriptable, uuid(d1f28e94-3a6e-4050-a5f5-2e81b1fc2a43)]
- interface nsIInputStreamCallback : nsISupports
- {
- /**
- * Called to indicate that the stream is either readable or closed.
- *
- * @param aStream
- * The stream whose asyncWait method was called.
- */
- void onInputStreamReady(in nsIAsyncInputStream aStream);
- };
-