public void SparqlUpdateCreateDrop()
{
TripleStore store = new TripleStore();
Console.WriteLine("Store has " + store.Graphs.Count + " Graphs");
//Create a couple of Graphs using Create Commands
CreateCommand create1 = new CreateCommand(new Uri("http://example.org/1"));
CreateCommand create2 = new CreateCommand(new Uri("http://example.org/2"));
store.ExecuteUpdate(create1);
store.ExecuteUpdate(create2);
Assert.AreEqual(3, store.Graphs.Count, "Store should have now had three Graphs");
Assert.AreEqual(0, store.Triples.Count(), "Store should have no triples at this point");
//Trying the same Create again should cause an error
try
{
store.ExecuteUpdate(create1);
Assert.Fail("Executing a CREATE command twice without the SILENT modifier should error");
}
catch (SparqlUpdateException)
{
Console.WriteLine("Executing a CREATE command twice without the SILENT modifier errored as expected");
}
//Equivalent Create with SILENT should not error
CreateCommand create3 = new CreateCommand(new Uri("http://example.org/1"), true);
try
{
store.ExecuteUpdate(create3);
Console.WriteLine("Executing a CREATE for an existing Graph with the SILENT modifier suppressed the error as expected");
}
catch (SparqlUpdateException)
{
Assert.Fail("Executing a CREATE for an existing Graph with the SILENT modifier should not error");
}
DropCommand drop1 = new DropCommand(new Uri("http://example.org/1"));
store.ExecuteUpdate(drop1);
Assert.AreEqual(2, store.Graphs.Count, "Store should have only 2 Graphs after we executed the DROP command");
try
{
store.ExecuteUpdate(drop1);
Assert.Fail("Trying to DROP a non-existent Graph should error");
}
catch (SparqlUpdateException)
{
Console.WriteLine("Trying to DROP a non-existent Graph produced an error as expected");
}
DropCommand drop2 = new DropCommand(new Uri("http://example.org/1"), ClearMode.Graph, true);
try
{
store.ExecuteUpdate(drop2);
Console.WriteLine("Trying to DROP a non-existent Graph with the SILENT modifier suppressed the error as expected");
}
catch (SparqlUpdateException)
{
Assert.Fail("Trying to DROP a non-existent Graph with the SILENT modifier should suppress the error");
}
}
/// <summary>
/// Processes a DROP command
/// </summary>
/// <param name="cmd">Drop Command</param>
public void ProcessDropCommand(DropCommand cmd)
{
this.ProcessCommand(cmd);
}
/// <summary>
/// Processes a DROP command
/// </summary>
/// <param name="cmd">Drop Command</param>
public void ProcessDropCommand(DropCommand cmd)
{
if (this._manager is IUpdateableGenericIOManager)
{
((IUpdateableGenericIOManager)this._manager).Update(cmd.ToString());
}
else
{
try
{
Graph g;
switch (cmd.Mode)
{
case ClearMode.Graph:
case ClearMode.Default:
if (this._manager.DeleteSupported)
{
//If available use DeleteGraph()
this._manager.DeleteGraph(cmd.TargetUri);
}
else if ((cmd.TargetUri == null && (this._manager.IOBehaviour & IOBehaviour.OverwriteDefault) != 0) || (cmd.TargetUri != null && (this._manager.IOBehaviour & IOBehaviour.OverwriteNamed) != 0))
{
//Can approximate by saving an empty Graph over the existing Graph
g = new Graph();
g.BaseUri = cmd.TargetUri;
this._manager.SaveGraph(g);
}
else if (this._manager.UpdateSupported && (this._manager.IOBehaviour & IOBehaviour.CanUpdateDeleteTriples) != 0)
{
//Can approximate by loading the Graph and then deleting all Triples from it
g = new NonIndexedGraph();
this._manager.LoadGraph(g, cmd.TargetUri);
this._manager.UpdateGraph(cmd.TargetUri, null, g.Triples);
}
else
{
throw new SparqlUpdateException("Unable to evaluate a DROP command as the underlying store does not provide appropriate IO Behaviour to approximate this command");
}
break;
case ClearMode.All:
case ClearMode.Named:
if (this._manager.ListGraphsSupported)
{
List<Uri> graphs = this._manager.ListGraphs().ToList();
foreach (Uri u in graphs)
{
if (this._manager.DeleteSupported)
{
//If available use DeleteGraph()
this._manager.DeleteGraph(u);
}
else if ((u == null && (this._manager.IOBehaviour & IOBehaviour.OverwriteDefault) != 0) || (u != null && (this._manager.IOBehaviour & IOBehaviour.OverwriteNamed) != 0))
{
//Can approximate by saving an empty Graph over the existing Graph
g = new Graph();
g.BaseUri = u;
this._manager.SaveGraph(g);
}
else if (this._manager.UpdateSupported && (this._manager.IOBehaviour & IOBehaviour.CanUpdateDeleteTriples) != 0)
{
//Can approximate by loading the Graph and then deleting all Triples from it
g = new NonIndexedGraph();
this._manager.LoadGraph(g, u);
this._manager.UpdateGraph(u, null, g.Triples);
}
else
{
throw new SparqlUpdateException("Unable to evaluate a DROP command as the underlying store does not provide appropriate IO Behaviour to approximate this command");
}
}
}
else
{
throw new NotSupportedException("The Generic Update processor does not support this form of the DROP command");
}
break;
}
}
catch
{
if (!cmd.Silent) throw;
}
}
}
/// <summary>
/// Processes a DROP command
/// </summary>
/// <param name="cmd">Drop Command</param>
public void ProcessDropCommand(DropCommand cmd)
{
if (this._manager is IUpdateableGenericIOManager)
{
((IUpdateableGenericIOManager)this._manager).Update(cmd.ToString());
}
else
{
try
{
Graph g;
switch (cmd.Mode)
{
case ClearMode.Graph:
case ClearMode.Default:
g = new Graph();
g.BaseUri = cmd.TargetUri;
this._manager.SaveGraph(g);
break;
case ClearMode.All:
case ClearMode.Named:
if (this._manager.ListGraphsSupported)
{
List<Uri> graphs = this._manager.ListGraphs().ToList();
foreach (Uri u in graphs)
{
g = new Graph();
g.BaseUri = u;
this._manager.SaveGraph(g);
}
}
else
{
throw new NotSupportedException("The Generic Update processor does not support this form of the DROP command");
}
break;
}
}
catch
{
if (!cmd.Silent) throw;
}
}
}
/// <summary>
/// Processes a DROP command
/// </summary>
/// <param name="cmd">Drop Command</param>
/// <param name="context">SPARQL Update Evaluation Context</param>
protected virtual void ProcessDropCommandInternal(DropCommand cmd, SparqlUpdateEvaluationContext context)
{
cmd.Evaluate(context);
}
/// <summary>
/// Processes a DROP command
/// </summary>
/// <param name="cmd">Drop Command</param>
public void ProcessDropCommand(DropCommand cmd)
{
this.ProcessDropCommandInternal(cmd, this.GetContext());
}
private void TryParseDropCommand(SparqlUpdateParserContext context)
{
bool silent = false;
//May possibly have a SILENT Keyword
IToken next = context.Tokens.Dequeue();
if (next.TokenType == Token.SILENT)
{
silent = true;
next = context.Tokens.Dequeue();
}
//Then expect a GRAPH followed by a URI or one of the DEFAULT/NAMED/ALL keywords
if (next.TokenType == Token.GRAPH)
{
Uri u = this.TryParseGraphRef(context);
DropCommand cmd = new DropCommand(u, ClearMode.Graph, silent);
context.CommandSet.AddCommand(cmd);
}
else if (next.TokenType == Token.DEFAULT)
{
context.CommandSet.AddCommand(new DropCommand(ClearMode.Default, silent));
}
else if (next.TokenType == Token.NAMED)
{
context.CommandSet.AddCommand(new DropCommand(ClearMode.Named, silent));
}
else if (next.TokenType == Token.ALLWORD)
{
context.CommandSet.AddCommand(new DropCommand(ClearMode.All, silent));
}
else
{
throw ParserHelper.Error("Unexpected Token '" + next.GetType().ToString() + "' encountered, expected a GRAPH <URI> to specify the Graph to DROP or one of the DEFAULT/NAMED/ALL keywords", next);
}
}
