/// <summary>
/// Open a DSC fileset as a LINQ-to-HPC IQueryable{T}.
/// </summary>
/// <typeparam name="T">The type of the records in the table.</typeparam>
/// <param name="dscFileSetName">The name of the DSC fileset. </param>
/// <returns>An IQueryable{T} representing the data and associated with the HPC LINQ query provider.</returns>
public IQueryable <T> FromDsc <T>(string fileSetName)
{
ThrowIfDisposed();
string fullPath = DataPath.MakeDscStreamUri(_dscService, fileSetName);
try {
DscFileSet fs = _dscService.GetFileSet(fileSetName);
if (!fs.IsSealed())
{
throw new DryadLinqException(HpcLinqErrorCode.FileSetMustBeSealed,
SR.FileSetMustBeSealed);
}
int fileCount = fs.GetFiles().Count();
if (fileCount < 1)
{
throw new DryadLinqException(HpcLinqErrorCode.FileSetMustHaveAtLeastOneFile,
SR.FileSetMustHaveAtLeastOneFile);
}
}
catch (DscException dscEx) {
throw new DryadLinqException(HpcLinqErrorCode.FileSetCouldNotBeOpened,
SR.FileSetCouldNotBeOpened, dscEx);
}
DryadLinqQuery <T> q = DataProvider.GetPartitionedTable <T>(this, fullPath);
q.CheckAndInitialize(); // force the data-info checks.
return(q);
}
public IEnumerator <T> GetEnumerator()
{
List <string[]> filePathList; // a list of dsc files, each of which is represented by an array holding the replica paths
DscCompressionScheme compressionScheme;
try
{
DscFileSet fileSet = m_context.DscService.GetFileSet(m_fileSetName);
filePathList = fileSet.GetFiles().Select(file => file.ReadPaths).ToList();
DryadLinqMetaData metaData = DryadLinqMetaData.FromDscStream(m_context, m_fileSetName);
compressionScheme = metaData.CompressionScheme;
}
catch (Exception e)
{
throw new DryadLinqException(HpcLinqErrorCode.FailedToGetReadPathsForStream,
String.Format(SR.FailedToGetReadPathsForStream, this.m_fileSetName), e);
}
return(new TableEnumerator(m_context, filePathList, m_fileSetName, compressionScheme));
}