pjs/xpcom/io/nsIInputStream.idl

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/* -*- Mode: C++; tab-width: 2; 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 "nsISupports.idl"
interface nsIInputStream;
interface nsIInputStreamObserver;
%{C++
/**
* The signature of the writer function passed to ReadSegments. This
* specifies where the data should go that gets read from the buffer.
* Implementers should return the following:
* @return NS_OK and writeCount - if successfully wrote something
* @return NS_BASE_STREAM_CLOSED - if no more can be written
* @return NS_BASE_STREAM_WOULD_BLOCK - if there is currently space to write (in
* a non-blocking mode)
* @return <other-error> - on failure
*/
typedef NS_CALLBACK(nsWriteSegmentFun)(nsIInputStream* in,
void* closure,
const char* fromRawSegment,
PRUint32 toOffset,
PRUint32 count,
PRUint32 *writeCount);
%}
native nsWriteSegmentFun(nsWriteSegmentFun);
[scriptable, uuid(fa9c7f6c-61b3-11d4-9877-00c04fa0cf4a)]
interface nsIInputStream : nsISupports
{
/**
* Closes the stream.
*/
void close();
/**
* Return the number of bytes currently available in the stream
* @param aLength out parameter to hold the number of bytes
* if an error occurs, the parameter will be undefined
* @return error status
*/
unsigned long available();
/**
* Read data from the stream.
* @param aBuf the buffer into which the data is read
* @param aCount the maximum number of bytes to read
* @return aReadCount out parameter to hold the number of
* bytes read, eof if 0. if an error occurs, the
* read count will be undefined
*/
[noscript] unsigned long read(in charPtr buf, in unsigned long count);
/**
* Low-level read method that has access to the stream's underlying buffer. The
* writer function may be called multiple times for segmented buffers.
*/
[noscript] unsigned long readSegments(in nsWriteSegmentFun writer,
in voidPtr closure,
in unsigned long count);
/**
* Set this attribute to put the stream in non-blocking mode.
*/
readonly attribute boolean nonBlocking;
/**
* Allows users to set an observer on an input stream to receive notifications
* about the consumer emptying the input stream's underlying buffer, or closing the
* stream. This is necessary for non-blocking streams so that the producer can suspend
* itself until more data can be written.
*/
attribute nsIInputStreamObserver observer;
};
[scriptable, uuid(019d67cc-61b4-11d4-9877-00c04fa0cf4a)]
interface nsIInputStreamObserver : nsISupports
{
/**
* Called when the input stream's consumer has read all the existing data from the stream.
*/
void onEmpty(in nsIInputStream outStr);
/**
* Called when the consumer closes its end of the stream.
*/
void onClose(in nsIInputStream outStr);
};