gecko-dev/xpcom/io/nsIStorageStream.idl
fur%netscape.com 79b25969d2 Bug #8305, r: valeski, rickg
The storage stream provides an internal buffer that
can be filled by a client using a single output
stream.  One or more independent input streams can
be created to read the data out non-destructively.
The implementation uses a segmented buffer
internally to avoid realloc'ing of large buffers.
1999-11-16 19:14:08 +00:00

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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 Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998-1999 Netscape Communications Corporation. All
* Rights Reserved.
*
*/
#include "nsISupports.idl"
#include "nsrootidl.idl"
interface nsIAllocator;
interface nsIInputStream;
interface nsIOutputStream;
/**
* The nsIStorageStream interface maintains an internal data buffer that can be
* filled using a single output stream. One or more independent input streams
* can be created to read the data from the buffer non-destructively.
*/
[scriptable, uuid(604ad9d0-753e-11d3-90ca-0040056a906e)]
interface nsIStorageStream : nsISupports
{
/**
* Get a reference to the one and only output stream for this instance.
* The zero-based startPosition argument is used is used to set the initial
* write cursor position. The startPosition cannot be set larger than the
* current buffer length. Calling this method has the side-effect of
* truncating the internal buffer to startPosition bytes.
*/
nsIOutputStream getOutputStream(in PRInt32 startPosition);
/**
* Create a new input stream to read data (written by the singleton output
* stream) from the internal buffer. Multiple, independent input streams
* can be created.
*/
nsIInputStream newInputStream(in PRInt32 startPosition);
/**
* The length attribute indicates the total number of bytes stored in the
* nsIStorageStream internal buffer, regardless of any consumption by input
* streams. Assigning to the length field can be used to truncate the
* buffer data, but can not be used when either the instance's output
* stream is in use.
*
* @See #writeInProgress */
attribute PRUint32 length;
/**
* True, when output stream has not yet been Close'ed
*/
readonly attribute boolean writeInProgress;
};
%{C++
// Factory method
NS_COM nsresult
NS_NewStorageStream(PRUint32 segmentSize, PRUint32 maxSize, nsIStorageStream **result);
%}