gecko-dev/xpcom/io/nsIOutputStream.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 nsIOutputStream;
interface nsIOutputStreamObserver;
interface nsIInputStream;
%{C++
/**
* The signature for the reader function passed to WriteSegment. This
* specifies where the data should come from that gets written into the buffer.
* Implementers should return the following:
* @return NS_OK and readCount > 0 - if successfully read something
* @return NS_OK and readCount == 0 - if no more to read (EOF)
* @return NS_BASE_STREAM_WOULD_BLOCK - if there is currently no data (in
* a non-blocking mode)
* @return <other-error> - on failure
*/
typedef NS_CALLBACK(nsReadSegmentFun)(nsIOutputStream* out,
void* closure,
char* toRawSegment,
PRUint32 fromOffset,
PRUint32 count,
PRUint32 *readCount);
%}
native nsReadSegmentFun(nsReadSegmentFun);
[scriptable, uuid(0d0acd2a-61b4-11d4-9877-00c04fa0cf4a)]
interface nsIOutputStream : nsISupports
{
/**
* Closes the stream.
*/
void close();
/**
* Flushes the stream.
*/
void flush();
/** Write data into the stream.
* @param aBuf the buffer from which the data is read
* @param aCount the maximum number of bytes to write
* @return aWriteCount out parameter to hold the number of
* bytes written. if an error occurs, the writecount
* is undefined
*/
unsigned long write(in string buf, in unsigned long count);
/**
* Writes data into the stream from an input stream.
* Implementer's note: This method is defined by this interface in order
* to allow the output stream to efficiently copy the data from the input
* stream into its internal buffer (if any). If this method was provide
* as an external facility, a separate char* buffer would need to be used
* in order to call the output stream's other Write method.
* @param fromStream the stream from which the data is read
* @param count the maximun number of bytes to write
* @return aWriteCount out parameter to hold the number of
* bytes written. if an error occurs, the writecount
* is undefined
*/
unsigned long writeFrom(in nsIInputStream inStr,
in unsigned long count);
/**
* Low-level write method that has access to the stream's underlying buffer. The
* reader function may be called multiple times for segmented buffers.
*/
[noscript] unsigned long writeSegments(in nsReadSegmentFun reader,
in voidPtr closure,
in unsigned long count);
/**
* Set this attribute to put the stream in non-blocking mode.
*/
attribute boolean nonBlocking;
/**
* Allows users to set an observer on an output stream to receive notifications
* about the producer writing data into the output stream, or filling the buffer.
* This is necessary for non-blocking streams so that the consumer can suspend
* itself until more data is available.
*/
attribute nsIOutputStreamObserver observer;
};
[scriptable, uuid(12314194-61b4-11d4-9877-00c04fa0cf4a)]
interface nsIOutputStreamObserver : nsISupports
{
/**
* Called when the output stream's producer has written more data into the stream.
*/
void onWrite(in nsIOutputStream inStr,
in unsigned long amount);
/**
* Called when the stream's underlying buffer becomes full.
*/
void onFull(in nsIOutputStream inStr);
};