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#include "SkTypes.h"
9
10class SkStream;
11class SkStreamRewindable;
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 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 be unreffed and no longer used directly.
30     *  @param minBufferSize Minimum size of buffer required.
31     *  @return An SkStream that can buffer at least minBufferSize, or
32     *      NULL on failure.
33     */
34    static SkStreamRewindable* Create(SkStream* stream, size_t minBufferSize);
35};
36