gecko-dev/netwerk/base/public/nsIStreamProvider.idl
dougt%netscape.com 128f95aa9b Relanding Necko Changes.
Revising nsIChannel to allow for overlapped i/o. This consists of three parts:

1. Factoring nsIChannel into a protocol specific part, the nsIChannel, and a socket specific, the nsITransport.
2. Derive the nsIChannel from a nsIRequest.
2. Changes the notification system from necko and the URILoader to pass the nsIRequest interface instead of nsIChannel interface.

This goal stems from wanting to be able to have active AsyncRead and AsyncWrite operations on nsSocketTransport.
This is desired because it would greatly simplify the task of maintaining persistent/reusable socket connections
for FTP, HTTP, and Imap (and potentially other protocols). The problem with the existing nsIChannel interface is
that it does not allow one to selectively suspend just one of the read or write operations while keeping the other active.

r=darin@netscape.com
sr=rpotts@netscape.com
2001-02-21 20:38:08 +00:00

101 lines
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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include "nsIStreamObserver.idl"
interface nsIChannel;
interface nsIInputStream;
interface nsIOutputStream;
interface nsIEventQueue;
/**
* The nsIChannel::AsyncWrite notification handler. It provides
* data to the channel, when the channel is ready to accept it.
*/
[scriptable, uuid(d10ef7a9-b728-43d4-9c49-74172186d691)]
interface nsIStreamProvider : nsIStreamObserver
{
/**
* Called when data may be written to the channel.
*
* @param request - the request returned by AsyncWrite
* @param ctxt - opaque parameter passed to AsyncWrite
* @param output - output stream for writing data chunk
* @param offset - current stream position (informational)
* @param count - number of bytes that can be written without blocking
*
* @return NS_OK - if successfully wrote something.
* @return NS_BASE_STREAM_CLOSED - if done writing data. NOTE: this is
* NOT equivalent to writing zero bytes and returning NS_OK.
* @return NS_BASE_STREAM_WOULD_BLOCK - if no data can be written at
* this time. This implicitly calls Suspend on the channel. Call
* Resume on the channel to continue the AsyncWrite when more data
* becomes available.
* @return <other-error> - if failure.
*/
void onDataWritable(in nsIRequest request,
in nsISupports ctxt,
in nsIOutputStream output,
in unsigned long offset,
in unsigned long count);
};
/**
* A stream provider proxy is used to ship data over to another thread specified
* by the thread's event queue. The "true" stream provider's methods are
* invoked on the other thread.
*
* This interface only provides the initialization needed after construction.
* Otherwise, these objects may be used as a nsIStreamProvider.
*/
[scriptable, uuid(5c3b0bac-605a-49ac-880e-5c8b993f7d2b)]
interface nsIStreamProviderProxy : nsIStreamProvider
{
/**
* Initializes an nsIStreamProviderProxy.
*
* @param provider - receives provider notifications on the other thread.
* @param eventQ - may be NULL indicating the calling thread's event queue.
*/
void init(in nsIStreamProvider provider,
in nsIEventQueue eventQ,
in unsigned long bufferSegmentSize,
in unsigned long bufferMaxSize);
};
/**
* A simple stream provider can be used with AsyncWrite to supply data from
* an existing input stream.
*/
[scriptable, uuid(c20bb3b9-0755-4eff-9222-3537f9e89082)]
interface nsISimpleStreamProvider : nsIStreamProvider
{
/**
* Initialize the simple stream provider.
*
* @param - data will be read from this input stream to the channel
* @param - optional stream observer (can be NULL)
*/
void init(in nsIInputStream source,
in nsIStreamObserver observer);
};