1/*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkFrontBufferedStream_DEFINED
9#define SkFrontBufferedStream_DEFINED
10
11#include "include/core/SkStream.h"
12
13/**
14 * Specialized stream that buffers the first X bytes of a stream,
15 * where X is passed in by the user. Note that unlike some buffered
16 * stream APIs, once more bytes than can fit in the buffer are read,
17 * no more buffering is done. This stream is designed for a use case
18 * where the caller knows that rewind will only be called from within
19 * X bytes (inclusive), and the wrapped stream is not necessarily
20 * able to rewind at all.
21 */
22class SK_API SkFrontBufferedStream {
23public:
24 /**
25 * Creates a new stream that wraps and buffers an SkStream.
26 * @param stream SkStream to buffer. If stream is NULL, NULL is
27 * returned. When this call succeeds (i.e. returns non NULL),
28 * SkFrontBufferedStream is expected to be the only owner of
29 * stream, so it should no be longer used directly.
30 * SkFrontBufferedStream will delete stream upon deletion.
31 * @param minBufferSize Minimum size of buffer required.
32 * @return An SkStream that can buffer at least minBufferSize, or
33 * NULL on failure. The caller is required to delete when finished with
34 * this object.
35 */
36 static std::unique_ptr<SkStreamRewindable> Make(std::unique_ptr<SkStream> stream,
37 size_t minBufferSize);
38};
39#endif // SkFrontBufferedStream_DEFINED
40