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 FrontBufferedStream_DEFINED 9 #define FrontBufferedStream_DEFINED 10 11 #include "include/core/SkStream.h" 12 13 namespace android { 14 namespace skia { 15 /** 16 * Specialized stream that buffers the first X bytes of a stream, 17 * where X is passed in by the user. Note that unlike some buffered 18 * stream APIs, once more bytes than can fit in the buffer are read, 19 * no more buffering is done. This stream is designed for a use case 20 * where the caller knows that rewind will only be called from within 21 * X bytes (inclusive), and the wrapped stream is not necessarily 22 * able to rewind at all. 23 */ 24 class SK_API FrontBufferedStream { 25 public: 26 /** 27 * Creates a new stream that wraps and buffers an SkStream. 28 * @param stream SkStream to buffer. If stream is NULL, NULL is 29 * returned. When this call succeeds (i.e. returns non NULL), 30 * FrontBufferedStream is expected to be the only owner of 31 * stream, so it should no be longer used directly. 32 * FrontBufferedStream will delete stream upon deletion. 33 * @param minBufferSize Minimum size of buffer required. 34 * @return An SkStream that can buffer at least minBufferSize, or 35 * NULL on failure. The caller is required to delete when finished with 36 * this object. 37 */ 38 static std::unique_ptr<SkStreamRewindable> Make(std::unique_ptr<SkStream> stream, 39 size_t minBufferSize); 40 }; 41 } // namespace skia 42 } // namespace android 43 #endif // FrontBufferedStream_DEFINED 44