/* ***** 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 * * 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(a5f255ab-4801-4161-8816-277ac92f6ad1)] 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. This * parameter may be null to clear an existing callback. * @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); };