/// <summary>
/// Thread Worker method which writes Graphs to the output
/// </summary>
/// <param name="globalContext">Context for writing the Store</param>
private void SaveGraphs(ThreadedStoreWriterContext globalContext)
{
try
{
Uri u = globalContext.GetNextUri();
while (u != null)
{
//Get the Graph from the Store
if (WriterHelper.IsDefaultGraph(u) && !globalContext.Store.HasGraph(u)) u = null;
IGraph g = globalContext.Store.Graphs[u];
//Generate the Graph Output and add to Stream
NTriplesWriterContext context = new NTriplesWriterContext(g, new System.IO.StringWriter(), globalContext.PrettyPrint, globalContext.HighSpeedModePermitted);
String graphContent = this.GraphToNQuads(globalContext, context);
if (!graphContent.Equals(String.Empty))
{
try
{
Monitor.Enter(globalContext.Output);
globalContext.Output.WriteLine(graphContent);
globalContext.Output.Flush();
}
catch
{
throw;
}
finally
{
Monitor.Exit(globalContext.Output);
}
}
//Get the Next Uri
u = globalContext.GetNextUri();
}
}
catch (ThreadAbortException)
{
//We've been terminated, don't do anything
#if !SILVERLIGHT
Thread.ResetAbort();
#endif
}
catch (Exception ex)
{
throw new RdfStorageException("Error in Threaded Writer in Thread ID " + Thread.CurrentThread.ManagedThreadId, ex);
}
}
/// <summary>
/// Converts a Triple into relevant NQuads Syntax
/// </summary>
/// <param name="context">Writer Context</param>
/// <param name="t">Triple to convert</param>
/// <returns></returns>
private String TripleToNQuads(NTriplesWriterContext context, Triple t)
{
StringBuilder output = new StringBuilder();
output.Append(this.NodeToNTriples(context, t.Subject, TripleSegment.Subject));
output.Append(" ");
output.Append(this.NodeToNTriples(context, t.Predicate, TripleSegment.Predicate));
output.Append(" ");
output.Append(this.NodeToNTriples(context, t.Object, TripleSegment.Object));
if (t.GraphUri != null && !WriterHelper.IsDefaultGraph(t.GraphUri))
{
output.Append(" <");
output.Append(context.UriFormatter.FormatUri(t.GraphUri));
output.Append(">");
}
output.Append(" .");
return output.ToString();
}
/// <summary>
/// Converts a Node into relevant NTriples Syntax
/// </summary>
/// <param name="n">Node to convert</param>
/// <param name="context">Writer Context</param>
/// <param name="segment">Triple Segment being written</param>
/// <returns></returns>
private String NodeToNTriples(NTriplesWriterContext context, INode n, TripleSegment segment)
{
switch (n.NodeType)
{
case NodeType.Blank:
if (segment == TripleSegment.Predicate) throw new RdfOutputException(WriterErrorMessages.BlankPredicatesUnserializable("NQuads"));
break;
case NodeType.Literal:
if (segment == TripleSegment.Subject) throw new RdfOutputException(WriterErrorMessages.LiteralSubjectsUnserializable("NQuads"));
if (segment == TripleSegment.Predicate) throw new RdfOutputException(WriterErrorMessages.LiteralPredicatesUnserializable("NQuads"));
break;
case NodeType.Uri:
break;
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("NQuads"));
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("NQuads"));
}
return context.NodeFormatter.Format(n);
}
private String GraphToNQuads(ThreadedStoreWriterContext globalContext, NTriplesWriterContext context)
{
if (context.Graph.IsEmpty) return String.Empty;
if (context.PrettyPrint && !WriterHelper.IsDefaultGraph(context.Graph.BaseUri))
{
context.Output.WriteLine("# Graph: " + context.Graph.BaseUri.ToString());
}
foreach (Triple t in context.Graph.Triples)
{
context.Output.WriteLine(this.TripleToNQuads(context, t));
}
context.Output.WriteLine();
return context.Output.ToString();
}
/// <summary>
/// Saves a Store in NQuads format
/// </summary>
/// <param name="store">Store to save</param>
/// <param name="parameters">Parameters indicating a Stream to write to</param>
public void Save(ITripleStore store, IStoreParams parameters)
{
ThreadedStoreWriterContext context = null;
if (parameters is StreamParams)
{
//Create a new Writer Context
#if !SILVERLIGHT
((StreamParams)parameters).Encoding = Encoding.ASCII;
#endif
context = new ThreadedStoreWriterContext(store, ((StreamParams)parameters).StreamWriter, this._prettyPrint, false);
}
else if (parameters is TextWriterParams)
{
context = new ThreadedStoreWriterContext(store, ((TextWriterParams)parameters).TextWriter, this._prettyPrint, false);
}
if (context != null)
{
//Check there's something to do
if (context.Store.Graphs.Count == 0)
{
context.Output.Close();
return;
}
try
{
if (this._multiThreaded)
{
//Queue the Graphs to be written
foreach (IGraph g in context.Store.Graphs)
{
if (g.BaseUri == null)
{
context.Add(UriFactory.Create(GraphCollection.DefaultGraphUri));
}
else
{
context.Add(g.BaseUri);
}
}
//Start making the async calls
List<IAsyncResult> results = new List<IAsyncResult>();
SaveGraphsDelegate d = new SaveGraphsDelegate(this.SaveGraphs);
for (int i = 0; i < this._threads; i++)
{
results.Add(d.BeginInvoke(context, null, null));
}
//Wait for all the async calls to complete
WaitHandle.WaitAll(results.Select(r => r.AsyncWaitHandle).ToArray());
RdfThreadedOutputException outputEx = new RdfThreadedOutputException(WriterErrorMessages.ThreadedOutputFailure("TSV"));
foreach (IAsyncResult result in results)
{
try
{
d.EndInvoke(result);
}
catch (Exception ex)
{
outputEx.AddException(ex);
}
}
context.Output.Close();
//If there were any errors we'll throw an RdfThreadedOutputException now
if (outputEx.InnerExceptions.Any()) throw outputEx;
}
else
{
foreach (IGraph g in context.Store.Graphs)
{
NTriplesWriterContext graphContext = new NTriplesWriterContext(g, context.Output);
foreach (Triple t in g.Triples)
{
context.Output.WriteLine(this.TripleToNQuads(graphContext, t));
}
}
context.Output.Close();
}
}
catch
{
try
{
context.Output.Close();
}
catch
{
//Just cleaning up
}
throw;
}
}
else
{
throw new RdfStorageException("Parameters for the NQuadsWriter must be of the type StreamParams/TextWriterParams");
}
}
/// <summary>
/// Converts a Triple into relevant NTriples Syntax
/// </summary>
/// <param name="context">Writer Context</param>
/// <param name="t">Triple to convert</param>
/// <returns></returns>
private String TripleToNTriples(NTriplesWriterContext context, Triple t)
{
StringBuilder output = new StringBuilder();
output.Append(this.NodeToNTriples(context, t.Subject, TripleSegment.Subject));
output.Append(" ");
output.Append(this.NodeToNTriples(context, t.Predicate, TripleSegment.Predicate));
output.Append(" ");
output.Append(this.NodeToNTriples(context, t.Object, TripleSegment.Object));
output.Append(" .");
return output.ToString();
}
/// <summary>
/// Saves the Graph in NTriples Syntax to the given stream
/// </summary>
/// <param name="g">Graph to save</param>
/// <param name="output">Stream to save to</param>
public void Save(IGraph g, TextWriter output)
{
try
{
NTriplesWriterContext context = new NTriplesWriterContext(g, output);
List<Triple> ts = g.Triples.ToList();
if (this._sort) ts.Sort();
foreach (Triple t in ts)
{
output.WriteLine(this.TripleToNTriples(context, t));
}
output.Close();
}
catch
{
//Try and ensure the Stream gets closed
try
{
output.Close();
}
catch
{
//No Catch actions
}
throw;
}
}
