PBufWrapper.h

00001 /*
00002 The MIT License
00003 Copyright (c) 2019 Lehrstuhl Informatik 11 - RWTH Aachen University
00004 Permission is hereby granted, free of charge, to any person obtaining a copy
00005 of this software and associated documentation files (the "Software"), to deal
00006 in the Software without restriction, including without limitation the rights
00007 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008 copies of the Software, and to permit persons to whom the Software is
00009 furnished to do so, subject to the following conditions:
00010 The above copyright notice and this permission notice shall be included in
00011 all copies or substantial portions of the Software.
00012 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00013 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00014 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00015 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00016 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00017 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00018 THE SOFTWARE
00019 
00020 This file is part of embeddedRTPS.
00021 
00022 Author: i11 - Embedded Software, RWTH Aachen University
00023 */
00024 
00025 #ifndef RTPS_PBUFWRAPPER_H
00026 #define RTPS_PBUFWRAPPER_H
00027 
00028 #include "lwip/pbuf.h"
00029 #include "rtps/common/types.h"
00030 
00031 namespace rtps {
00032 
00033 struct PBufWrapper {
00034 
00035   pbuf *firstElement = nullptr;
00036 
00037   PBufWrapper() = default;
00038   explicit PBufWrapper(pbuf *bufferToWrap);
00039   explicit PBufWrapper(DataSize_t length);
00040 
00041   // Shallow Copy. No copying of the underlying pbuf. Just another reference
00042   // like a shared pointer.
00043   PBufWrapper(const PBufWrapper &other);
00044   PBufWrapper &operator=(const PBufWrapper &other);
00045 
00046   PBufWrapper(PBufWrapper &&other) noexcept;
00047   PBufWrapper &operator=(PBufWrapper &&other) noexcept;
00048 
00049   ~PBufWrapper();
00050 
00051   PBufWrapper deepCopy() const;
00052 
00053   bool isValid() const;
00054 
00055   bool append(const uint8_t *data, DataSize_t length);
00056 
00057   /// Note that unused reserved memory is now part of the wrapper. New calls to
00058   /// append(uint8_t*[...]) will continue behind the appended wrapper
00059   void append(PBufWrapper &&other);
00060 
00061   bool reserve(DataSize_t length);
00062 
00063   /// After calling this function, data is added starting from the beginning
00064   /// again. It does not revert reserve.
00065   void reset();
00066 
00067   DataSize_t spaceLeft() const;
00068   DataSize_t spaceUsed() const;
00069 
00070 private:
00071   constexpr static pbuf_layer m_layer = PBUF_TRANSPORT;
00072   constexpr static pbuf_type m_type = PBUF_POOL;
00073 
00074   DataSize_t m_freeSpace = 0;
00075 
00076   bool increaseSizeBy(uint16_t length);
00077 
00078   void copySimpleMembersAndResetBuffer(const PBufWrapper &other);
00079 };
00080 
00081 } // namespace rtps
00082 
00083 #endif // RTPS_PBUFWRAPPER_H