michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkTypes.h"
michael@0: 
michael@0: class SkStream;
michael@0: class SkStreamRewindable;
michael@0: 
michael@0: /**
michael@0:  *  Specialized stream that buffers the first X bytes of a stream,
michael@0:  *  where X is passed in by the user. Note that unlike some buffered
michael@0:  *  stream APIs, once more bytes than can fit in the buffer are read,
michael@0:  *  no more buffering is done. This stream is designed for a use case
michael@0:  *  where the caller knows that rewind will only be called from within
michael@0:  *  X bytes (inclusive), and the wrapped stream is not necessarily
michael@0:  *  able to rewind at all.
michael@0:  */
michael@0: class SkFrontBufferedStream {
michael@0: public:
michael@0:     /**
michael@0:      *  Creates a new stream that wraps and buffers an SkStream.
michael@0:      *  @param stream SkStream to buffer. If stream is NULL, NULL is
michael@0:      *      returned. When this call succeeds (i.e. returns non NULL),
michael@0:      *      SkFrontBufferedStream is expected to be the only owner of
michael@0:      *      stream, so it should be unreffed and no longer used directly.
michael@0:      *  @param minBufferSize Minimum size of buffer required.
michael@0:      *  @return An SkStream that can buffer at least minBufferSize, or
michael@0:      *      NULL on failure.
michael@0:      */
michael@0:     static SkStreamRewindable* Create(SkStream* stream, size_t minBufferSize);
michael@0: };