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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsISupports.idl"
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(44a200fe-6c2b-4b41-b4e3-63e8c14e7c0d)]
interface nsIStorageStream : nsISupports
{
/**
*
* Initialize the stream, setting up the amount of space that will be
* allocated for the stream's backing-store.
*
* @param segmentSize
* Size of each segment. Must be a power of two.
* @param maxSize
* Maximum total size of this stream. length will always be less
* than or equal to this value. Passing UINT32_MAX is safe.
*/
void init(in uint32_t segmentSize, in uint32_t maxSize);
/**
* 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 int32_t 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 int32_t 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 uint32_t length;
/**
* True, when output stream has not yet been Close'ed
*/
readonly attribute boolean writeInProgress;
};
%{C++
// Factory method
nsresult
NS_NewStorageStream(uint32_t segmentSize, uint32_t maxSize, nsIStorageStream **result);
%}