DataBufferFile.cpp

   1 #include <string.h>
   2 #include "DataBufferFile.hpp"
   3
   4 DataBufferFile::DataBufferFile( FILE* f, int secondaryBufferSize, Mode mode )
   5         : m_file( f )
   6         , m_buf( new char[BufSize] )
   7         , m_buf2( new char[BufSize] )
   8         , m_secBuf( new char[secondaryBufferSize] )
   9         , m_secBufSize( 0 )
  10         , m_mode( mode )
  11         , m_threadRunning( false )
  12 {
  13         if( mode == M_WRITE )
  14         {
  15                 m_offset = 0;
  16         }
  17         else
  18         {
  19                 m_offset = BufSize;
  20         }
  21 }
  22
  23 DataBufferFile::~DataBufferFile()
  24 {
  25         // Dump buffer to disk if needed
  26         if( m_mode == M_WRITE && m_offset != 0 )
  27         {
  28                 SaveBuffer();
  29         }
  30         if( m_threadRunning )
  31         {
  32                 pthread_join( m_thread, NULL );
  33         }
  34
  35         delete[] m_buf;
  36         delete[] m_buf2;
  37         delete[] m_secBuf;
  38
  39         fclose( m_file );
  40 }
  41
  42 int DataBufferFile::Read( void* ptr, int size )
  43 {
  44         int bufSize = m_secBufSize;
  45         m_secBufSize = 0;
  46
  47         memcpy( ptr, m_secBuf, bufSize );
  48
  49         return fread( (char*)ptr + bufSize, 1, size - bufSize, m_file ) + bufSize;
  50 }
  51
  52 int DataBufferFile::Write( void* _ptr, int _size )
  53 {
  54         int size = _size;
  55         char* ptr = (char*)_ptr;
  56
  57         while( size != 0 )
  58         {
  59                 int dataToWrite = std::min( size, BufSize - m_offset );
  60                 memcpy( m_buf + m_offset, ptr, dataToWrite );
  61                 ptr += dataToWrite;
  62                 m_offset += dataToWrite;
  63                 size -= dataToWrite;
  64
  65                 if( m_offset == BufSize )
  66                 {
  67                         SaveBuffer();
  68                 }
  69         }
  70
  71         return _size;
  72 }
  73
  74 void DataBufferFile::Store( void* ptr, int size )
  75 {
  76         memcpy( m_secBuf, ptr, size );
  77         m_secBufSize = size;
  78 }
  79
  80 void DataBufferFile::SaveBuffer()
  81 {
  82         if( m_threadRunning )
  83         {
  84                 pthread_join( m_thread, NULL );
  85         }
  86
  87         m_offsetToWrite = m_offset;
  88         m_offset = 0;
  89         std::swap( m_buf, m_buf2 );
  90
  91         pthread_create( &m_thread, NULL, &DataBufferFile::SaveBuffer, (void*)this );
  92         m_threadRunning = true;
  93 }
  94
  95 void* DataBufferFile::SaveBuffer( void* _ptr )
  96 {
  97         DataBufferFile* ptr = static_cast<DataBufferFile*>( _ptr );
  98
  99         if( ptr->m_offsetToWrite == BufSize )
 100         {
 101                 fwrite( ptr->m_buf2, BufSize, 1, ptr->m_file );
 102         }
 103         else
 104         {
 105                 fwrite( ptr->m_buf2, 1, ptr->m_offsetToWrite, ptr->m_file );
 106         }
 107
 108         return NULL;
 109 }