1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/io/nsIStorageStream.idl Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,69 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsISupports.idl"
1.10 +
1.11 +interface nsIInputStream;
1.12 +interface nsIOutputStream;
1.13 +
1.14 +/**
1.15 + * The nsIStorageStream interface maintains an internal data buffer that can be
1.16 + * filled using a single output stream. One or more independent input streams
1.17 + * can be created to read the data from the buffer non-destructively.
1.18 + */
1.19 +
1.20 +[scriptable, uuid(44a200fe-6c2b-4b41-b4e3-63e8c14e7c0d)]
1.21 +interface nsIStorageStream : nsISupports
1.22 +{
1.23 + /**
1.24 + *
1.25 + * Initialize the stream, setting up the amount of space that will be
1.26 + * allocated for the stream's backing-store.
1.27 + *
1.28 + * @param segmentSize
1.29 + * Size of each segment. Must be a power of two.
1.30 + * @param maxSize
1.31 + * Maximum total size of this stream. length will always be less
1.32 + * than or equal to this value. Passing UINT32_MAX is safe.
1.33 + */
1.34 + void init(in uint32_t segmentSize, in uint32_t maxSize);
1.35 +
1.36 + /**
1.37 + * Get a reference to the one and only output stream for this instance.
1.38 + * The zero-based startPosition argument is used is used to set the initial
1.39 + * write cursor position. The startPosition cannot be set larger than the
1.40 + * current buffer length. Calling this method has the side-effect of
1.41 + * truncating the internal buffer to startPosition bytes.
1.42 + */
1.43 + nsIOutputStream getOutputStream(in int32_t startPosition);
1.44 +
1.45 + /**
1.46 + * Create a new input stream to read data (written by the singleton output
1.47 + * stream) from the internal buffer. Multiple, independent input streams
1.48 + * can be created.
1.49 + */
1.50 + nsIInputStream newInputStream(in int32_t startPosition);
1.51 +
1.52 + /**
1.53 + * The length attribute indicates the total number of bytes stored in the
1.54 + * nsIStorageStream internal buffer, regardless of any consumption by input
1.55 + * streams. Assigning to the length field can be used to truncate the
1.56 + * buffer data, but can not be used when either the instance's output
1.57 + * stream is in use.
1.58 + *
1.59 + * @See #writeInProgress */
1.60 + attribute uint32_t length;
1.61 +
1.62 + /**
1.63 + * True, when output stream has not yet been Close'ed
1.64 + */
1.65 + readonly attribute boolean writeInProgress;
1.66 +};
1.67 +
1.68 +%{C++
1.69 +// Factory method
1.70 +nsresult
1.71 +NS_NewStorageStream(uint32_t segmentSize, uint32_t maxSize, nsIStorageStream **result);
1.72 +%}
