async_io.cpp

AsyncOp<void*> async_read_compressed_file( const char* pFileName )
{
  // async file open:
  AsyncOp<FileHandle> openOp = async_open( pFileName );
  
  // when the open is done: read the header:
  openOp.wait(); // ???? 
  FileHandle handle = openOp.result;
  
  FileHeader header;  // automatic storage ??
  
  AsyncOp<size_t> readOp = async_read( handle, 0u, sizeof( header ) );
  readOp.wait(); // ??
  
  //allocate some memory:
  uint8* pResult = (uint8*)malloc( header.uncompressedSize )
  
  // until done: read block+decompress
  uint64 fileOffset = sizeof( header );
  size_t blockSize = ...; // details..
  while( fileOffset < sizeof( header ) + header.compressedSize )
  {
    AsyncOp<size_t> readBlockOp = async_read( handle, pTarget, fileOffset, blockSize );
    readBlockOp.wait();
    AsyncOp<size_t> decompressBlockOp = async_decompress_inplace( pTarget, blockSize );
    decompressBlockOp.wait();
    size_t decompressedSize = decompressBlockOp.result;
    fileOffset += blockSize;
    pTarget += decompressedSize;
  }
  
  return createAsyncOp<void*>( pResult );
}

int main()
{
....
  AsyncOp<void*> readFile0 = async_read_compressed_file( "Test1.dat" );
  AsyncOp<void*> readFile1 = async_read_compressed_file( "Test2.dat" );

  uint doneCount = 0u;
  while( doneCount < 2u )
  {
    if( readFile0.isDone() )
    {
      // do something with the result..
      delete readFile0.result;
      doneCount++;
    }
    if( readFile1.isDone() )
    {
      // do something with the result..
      delete readFile1.result;
      doneCount++;
    }
  }

  // query result:
  
}