1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef LIBRARIES_NACL_IO_FIFO_CHAR_H_ 6 #define LIBRARIES_NACL_IO_FIFO_CHAR_H_ 7 8 #include <vector> 9 10 #include "nacl_io/fifo_interface.h" 11 12 #include "sdk_util/macros.h" 13 14 namespace nacl_io { 15 16 // FIFOChar 17 // 18 // A FIFOChar is a circular buffer, signalling FULL and EMPTY as appropriate. 19 class FIFOChar : public FIFOInterface { 20 public: 21 explicit FIFOChar(size_t size); 22 virtual ~FIFOChar(); 23 24 virtual bool IsEmpty(); 25 virtual bool IsFull(); 26 virtual bool Resize(size_t len); 27 28 virtual size_t ReadAvailable(); 29 virtual size_t WriteAvailable(); 30 31 // Reads out no more than the requested len without updating the tail. 32 // Returns actual amount read. 33 size_t Peek(void* buf, size_t len); 34 35 // Reads out the data making room in the FIFO. Returns actual amount 36 // read. 37 size_t Read(void* buf, size_t len); 38 39 // Writes into the FIFO no more than len bytes, returns actual amount 40 // written. 41 size_t Write(const void* buf, size_t len); 42 43 private: 44 char* buffer_; 45 size_t size_; // Size of the FIFO 46 size_t avail_; // How much data is currently available 47 size_t tail_; // Next read location 48 49 DISALLOW_COPY_AND_ASSIGN(FIFOChar); 50 }; 51 52 } // namespace nacl_io 53 54 #endif // LIBRARIES_NACL_IO_FIFO_CHAR_H_ 55
