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 "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 */ 22 class SK_API SkFrontBufferedStream { 23 public: 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