internal static DryadLinqMetaData Get(DryadLinqContext context, Uri dataSetUri)
{
string scheme = DataPath.GetScheme(dataSetUri);
DataProvider dataProvider = DataProvider.GetDataProvider(scheme);
return(dataProvider.GetMetaData(context, dataSetUri));
}
/// <summary>
/// Reads a specified dataset.
/// </summary>
/// <typeparam name="T">The record type of the dataset.</typeparam>
/// <param name="context">An instance of <see cref="DryadLinqContext"/></param>
/// <param name="dataSetUri">The URI of the dataset.</param>
/// <returns>A sequence of records as IEnumerable{T}.</returns>
public static IEnumerable <T> ReadData <T>(DryadLinqContext context, Uri dataSetUri)
{
string scheme = DataPath.GetScheme(dataSetUri);
DataProvider dataProvider = DataProvider.GetDataProvider(scheme);
dataSetUri = dataProvider.RewriteUri <T>(context, dataSetUri);
return(new DryadLinqQueryEnumerable <T>(context, dataProvider, dataSetUri));
}
/// <summary>
/// Get the dataset specified by a URI.
/// </summary>
/// <typeparam name="T">The record type of the dataset.</typeparam>
/// <param name="context">An instance of <see cref="DryadLinqContext"/></param>
/// <param name="dataSetUri">The URI of the dataset</param>
/// <returns>A query object representing the dsc file set data.</returns>
internal static DryadLinqQuery <T> GetPartitionedTable <T>(DryadLinqContext context, Uri dataSetUri)
{
string scheme = DataPath.GetScheme(dataSetUri);
DataProvider dataProvider = DataProvider.GetDataProvider(scheme);
DryadLinqProvider queryProvider = new DryadLinqProvider(context);
dataSetUri = dataProvider.RewriteUri <T>(context, dataSetUri);
return(new DryadLinqQuery <T>(null, queryProvider, dataProvider, dataSetUri));
}
/// <summary>
/// Reads the dataset specified by a URI.
/// </summary>
/// <typeparam name="T">The record type of the dataset</typeparam>
/// <param name="context">An instance of <see cref="DryadLinqContext"/></param>
/// <param name="dataSetUri">The URI of the dataset</param>
/// <param name="deserializer">A stream-based deserializer</param>
/// <returns>A sequence of records as IEnumerable{T}</returns>
internal static IEnumerable <T> ReadData <T>(DryadLinqContext context,
Uri dataSetUri,
Expression <Func <Stream, IEnumerable <T> > > deserializer)
{
string scheme = DataPath.GetScheme(dataSetUri);
DataProvider dataProvider = DataProvider.GetDataProvider(scheme);
dataSetUri = dataProvider.RewriteUri <T>(context, dataSetUri);
return(new DryadLinqQueryEnumerable <T>(context, dataProvider, dataSetUri, deserializer));
}
/// <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);
}
