Line data    Source code

       1             : /* Copyright (C) 2021 Wildfire Games.
       2             :  *
       3             :  * Permission is hereby granted, free of charge, to any person obtaining
       4             :  * a copy of this software and associated documentation files (the
       5             :  * "Software"), to deal in the Software without restriction, including
       6             :  * without limitation the rights to use, copy, modify, merge, publish,
       7             :  * distribute, sublicense, and/or sell copies of the Software, and to
       8             :  * permit persons to whom the Software is furnished to do so, subject to
       9             :  * the following conditions:
      10             :  *
      11             :  * The above copyright notice and this permission notice shall be included
      12             :  * in all copies or substantial portions of the Software.
      13             :  *
      14             :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
      15             :  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
      16             :  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
      17             :  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
      18             :  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
      19             :  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
      20             :  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
      21             :  */
      22             : 
      23             : #ifndef INCLUDED_WRITE_BUFFER
      24             : #define INCLUDED_WRITE_BUFFER
      25             : 
      26             : #include "lib/file/file.h"
      27             : 
      28         116 : class WriteBuffer
      29             : {
      30             : public:
      31             :     WriteBuffer();
      32             : 
      33             :     void Append(const void* data, size_t size);
      34             :     void Reserve(size_t size);
      35             :     void Overwrite(const void* data, size_t size, size_t offset);
      36             : 
      37         115 :     std::shared_ptr<u8> Data() const
      38             :     {
      39         115 :         return m_data;
      40             :     }
      41             : 
      42        2392 :     size_t Size() const
      43             :     {
      44        2392 :         return m_size;
      45             :     }
      46             : 
      47             : private:
      48             :     void EnsureSufficientCapacity(size_t size);
      49             : 
      50             :     size_t m_capacity;  // must come first (init order)
      51             : 
      52             :     std::shared_ptr<u8> m_data;
      53             :     size_t m_size;
      54             : };
      55             : 
      56             : 
      57             : class UnalignedWriter
      58             : {
      59             :     NONCOPYABLE(UnalignedWriter);
      60             : public:
      61             :     UnalignedWriter(const PFile& file, off_t ofs);
      62             :     ~UnalignedWriter();
      63             : 
      64             :     /**
      65             :      * add data to the align buffer, writing it out to disk if full.
      66             :      **/
      67             :     Status Append(const u8* data, size_t size) const;
      68             : 
      69             :     /**
      70             :      * zero-initialize any remaining space in the align buffer and write
      71             :      * it to the file. this is called by the destructor.
      72             :      **/
      73             :     void Flush() const;
      74             : 
      75             : private:
      76             :     Status WriteBlock() const;
      77             : 
      78             :     PFile m_file;
      79             :     std::shared_ptr<u8> m_alignedBuf;
      80             :     mutable off_t m_alignedOfs;
      81             :     mutable size_t m_bytesUsed;
      82             : };
      83             : 
      84             : typedef std::shared_ptr<UnalignedWriter> PUnalignedWriter;
      85             : 
      86             : #endif  // #ifndef INCLUDED_WRITE_BUFFER