/// <summary>
/// Stores an IEnumerable{T} at a specified location.
/// </summary>
/// <typeparam name="T">The record type of the data.</typeparam>
/// <param name="context">An instance of <see cref="DryadLinqContext"/></param>
/// <param name="source">The data to store.</param>
/// <param name="dataSetUri">The URI of the store location.</param>
/// <param name="metaData">The metadata of the data.</param>
/// <param name="outputScheme">The compression scheme.</param>
/// <param name="isTemp">true if the data is only stored temporarily.</param>
/// <returns>An instance of IQueryable{T} for the data.</returns>
internal static DryadLinqQuery <T> StoreData <T>(DryadLinqContext context,
IEnumerable <T> source,
Uri dataSetUri,
DryadLinqMetaData metaData,
CompressionScheme outputScheme,
bool isTemp = false)
{
string scheme = DataPath.GetScheme(dataSetUri);
DataProvider dataProvider = DataProvider.GetDataProvider(scheme);
dataSetUri = dataProvider.RewriteUri <T>(context, dataSetUri);
dataProvider.Ingress(context, source, dataSetUri, metaData, outputScheme, isTemp);
return(DataProvider.GetPartitionedTable <T>(context, dataSetUri));
}
/// <summary>
/// Stores an IEnumerable{T} at a specified location.
/// </summary>
/// <typeparam name="T">The record type of the data.</typeparam>
/// <param name="context">An instance of <see cref="DryadLinqContext"/></param>
/// <param name="source">The data to store.</param>
/// <param name="dataSetUri">The URI of the store location.</param>
/// <param name="metaData">The metadata of the data.</param>
/// <param name="outputScheme">The compression scheme.</param>
/// <param name="isTemp">true if the data is only stored temporarily.</param>
/// <param name="serializer">A stream-based serializer</param>
/// <param name="deserializer">A stream-based deserializer</param>
/// <returns>An instance of IQueryable{T} for the data.</returns>
internal static DryadLinqQuery <T> StoreData <T>(DryadLinqContext context,
IEnumerable <T> source,
Uri dataSetUri,
DryadLinqMetaData metaData,
CompressionScheme outputScheme,
bool isTemp,
Expression <Action <IEnumerable <T>, Stream> > serializer,
Expression <Func <Stream, IEnumerable <T> > > deserializer)
{
string scheme = DataPath.GetScheme(dataSetUri);
DataProvider dataProvider = DataProvider.GetDataProvider(scheme);
dataSetUri = dataProvider.RewriteUri <T>(context, dataSetUri);
dataProvider.Ingress(context, source, dataSetUri, metaData, outputScheme, isTemp, serializer);
DryadLinqQuery <T> res = DataProvider.GetPartitionedTable <T>(context, dataSetUri, deserializer);
res.CheckAndInitialize(); // must initialize
return(res);
}
// create DryadLinqMetaData from a query OutputNode
internal static DryadLinqMetaData FromOutputNode(HpcLinqContext context, DryadOutputNode node)
{
DryadLinqMetaData metaData = new DryadLinqMetaData();
if (!(DataPath.IsDsc(node.MetaDataUri) || DataPath.IsHdfs(node.MetaDataUri)))
{
throw new InvalidOperationException();
}
metaData.m_context = context;
metaData.m_dscStreamName = node.MetaDataUri;
metaData.m_elemType = node.OutputTypes[0];
metaData.m_compressionScheme = node.OutputCompressionScheme;
//metaData.m_version = context.ClientVersion;
//metaData.InitializeFlags();
//metaData.m_fp = 0UL;
//metaData.m_dataSetInfo = node.OutputDataSetInfo;
return(metaData);
}
// create DryadLinqMetaData from a query OutputNode
internal static DryadLinqMetaData Get(DryadLinqContext context, DLinqOutputNode node)
{
DryadLinqMetaData metaData = new DryadLinqMetaData();
if (!DataPath.IsValidDataPath(node.OutputUri))
{
throw new InvalidOperationException();
}
metaData.m_context = context;
metaData.m_dataSetUri = node.OutputUri;
metaData.m_elemType = node.OutputTypes[0];
metaData.m_compressionScheme = node.OutputCompressionScheme;
//metaData.m_version = context.ClientVersion();
//metaData.InitializeFlags();
//metaData.m_fp = 0UL;
//metaData.m_dataSetInfo = node.OutputDataSetInfo;
return(metaData);
}
//* streams plain enumerable data directly to DSC
internal static DryadLinqQuery <T> IngressDataDirectlyToDsc <T>(HpcLinqContext context,
IEnumerable <T> source,
string dscFileSetName,
DryadLinqMetaData metaData,
DscCompressionScheme outputScheme)
{
try
{
string dscFileSetUri = DataPath.MakeDscStreamUri(context.DscService.HostName, dscFileSetName);
if (source.Take(1).Count() == 0)
{
//there is no data.. we must create a FileSet with an empty file
//(the factory/stream approach opens files lazily and thus never opens a file if there is no data)
if (context.DscService.FileSetExists(dscFileSetName))
{
context.DscService.DeleteFileSet(dscFileSetName);
}
DscFileSet fileSet = context.DscService.CreateFileSet(dscFileSetName, outputScheme);
DscFile file = fileSet.AddNewFile(0);
string writePath = file.WritePath;
if (outputScheme == DscCompressionScheme.Gzip)
{
//even zero-byte file must go through the gzip-compressor (for headers etc).
using (Stream s = new FileStream(writePath, FileMode.Create))
{
var gzipStream = new GZipStream(s, CompressionMode.Compress);
gzipStream.Close();
}
}
else
{
StreamWriter sw = new StreamWriter(writePath, false);
sw.Close();
}
fileSet.Seal();
}
else
{
HpcLinqFactory <T> factory = (HpcLinqFactory <T>)HpcLinqCodeGen.GetFactory(context, typeof(T));
// new DscBlockStream(uri,Create,Write,compress) provides a DSC stream with one partition.
NativeBlockStream nativeStream = new DscBlockStream(dscFileSetUri, FileMode.Create, FileAccess.Write, outputScheme);
HpcRecordWriter <T> writer = factory.MakeWriter(nativeStream);
try
{
if (context.Configuration.AllowConcurrentUserDelegatesInSingleProcess)
{
foreach (T item in source)
{
writer.WriteRecordAsync(item);
}
}
else
{
foreach (T item in source)
{
writer.WriteRecordSync(item);
}
}
}
finally
{
writer.Close(); // closes the NativeBlockStream, which seals the dsc stream.
}
}
if (metaData != null)
{
DscFileSet fileSet = context.DscService.GetFileSet(dscFileSetName);
fileSet.SetMetadata(DryadLinqMetaData.RECORD_TYPE_NAME, Encoding.UTF8.GetBytes(metaData.ElemType.AssemblyQualifiedName));
}
return(DataProvider.GetPartitionedTable <T>(context, dscFileSetUri));
}
catch
{
// if we had a problem creating the empty fileset, try to delete it to avoid cruft being left in DSC.
try
{
context.DscService.DeleteFileSet(dscFileSetName);
}
catch
{
// suppress error during delete
}
throw; // rethrow the original exception.
}
}
internal static string MakeUniqueTemporaryHdfsFileSetUri(HpcLinqContext context)
{
string uri = DataPath.MakeHdfsStreamUri(context.Configuration.HdfsNameNode, MakeUniqueTemporaryDscFileSetName());
return(uri);
}
internal static string MakeUniqueTemporaryDscFileSetUri(HpcLinqContext context)
{
string uri = DataPath.MakeDscStreamUri(context.DscService.HostName, MakeUniqueTemporaryDscFileSetName());
return(uri);
}
