workbench/libs/asyncio/src/WriteAsync.c

   1 #include "async.h"
   2
   3
   4 _LIBCALL LONG
   5 WriteAsync( _REG( a0 ) AsyncFile *file, _REG( a1 ) APTR buffer, _REG( d0 ) LONG numBytes )
   6 {
   7 #ifdef ASIO_NOEXTERNALS
   8         struct ExecBase *SysBase = file->af_SysBase;
   9 #endif
  10         LONG totalBytes = 0;
  11
  12         /* this takes care of NIL: */
  13         if( !file->af_Handler )
  14         {
  15                 file->af_Offset         = file->af_Buffers[ 0 ];
  16                 file->af_BytesLeft      = file->af_BufferSize;
  17                 return( numBytes );
  18         }
  19
  20         while( numBytes > file->af_BytesLeft )
  21         {
  22                 if( file->af_BytesLeft )
  23                 {
  24                         CopyMem( buffer, file->af_Offset, file->af_BytesLeft );
  25
  26                         numBytes        -= file->af_BytesLeft;
  27                         buffer          =  ( APTR ) ( ( ULONG ) buffer + file->af_BytesLeft );
  28                         totalBytes      += file->af_BytesLeft;
  29                 }
  30
  31                 if( AS_WaitPacket( file ) < 0 )
  32                 {
  33                         return( -1 );
  34                 }
  35
  36                 /* send the current buffer out to disk */
  37                 AS_SendPacket( file, file->af_Buffers[ file->af_CurrentBuf ] );
  38
  39                 file->af_CurrentBuf     = 1 - file->af_CurrentBuf;
  40                 file->af_Offset         = file->af_Buffers[ file->af_CurrentBuf ];
  41                 file->af_BytesLeft      = file->af_BufferSize;
  42         }
  43
  44         CopyMem( buffer, file->af_Offset, numBytes );
  45         file->af_BytesLeft      -= numBytes;
  46         file->af_Offset         += numBytes;
  47
  48         return ( totalBytes + numBytes );
  49 }