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