/// <summary>
/// Queries a given commit point of a store using a SPARQL query
/// </summary>
/// <param name="commitPoint">The store commit point to be queried</param>
/// <param name="queryExpression">The SPARQL query string</param>
/// <param name="resultsMediaType">The media type for the serialization of the SPARQL results</param>
/// <returns>A stream containing the serialized query results</returns>
public Stream ExecuteQueryOnCommitPoint(CommitPointInfo commitPoint, string queryExpression, string resultsMediaType = null)
{
try
{
var resultsFormat = resultsMediaType == null ? SparqlResultsFormat.Xml : SparqlResultsFormat.GetResultsFormat(resultsMediaType);
var pstream = new MemoryStream();
var t = new Task(() => ServerCore.Query(commitPoint.StoreName, commitPoint.Id, queryExpression, resultsFormat, pstream));
t.Start();
t.Wait();
if (t.IsFaulted && t.Exception != null)
{
throw t.Exception;
}
var cStream = new MemoryStream(pstream.GetBuffer(), 0, (int)pstream.Length);
return(cStream);
}
catch (Exception ex)
{
Logging.LogError(BrightstarDB.BrightstarEventId.ServerCoreException, "Error executing query {0}@{1} {2}", commitPoint.StoreName, commitPoint.Id, queryExpression);
throw new BrightstarClientException(
String.Format("Error executing query {0}@{1} {2}. {3}", commitPoint.StoreName, commitPoint.Id,
queryExpression, ex.Message), ex);
}
}
public Stream ExecuteQuery(string storeName, string queryExpression, DateTime?ifNotModifiedSince, string resultsMediaType = null)
{
try {
var resultsFormat = resultsMediaType == null ? SparqlResultsFormat.Xml : SparqlResultsFormat.GetResultsFormat(resultsMediaType);
var pStream = new MemoryStream();
NodeCore.ProcessQuery(storeName, queryExpression, ifNotModifiedSince, resultsFormat, pStream);
var cStream = new MemoryStream(pStream.GetBuffer(), 0, (int)pStream.Length);
return(cStream);
}
catch (AggregateException aggregateException)
{
if (aggregateException.InnerException is BrightstarStoreNotModifiedException)
{
throw new BrightstarClientException("Store not modified", aggregateException.InnerException);
}
throw new BrightstarClientException("Error executing query", aggregateException.InnerException);
}
catch (BrightstarStoreNotModifiedException ex)
{
throw new BrightstarClientException("Store not modified", new ExceptionDetail(ex));
}
catch (Exception ex)
{
Logging.LogError(BrightstarDB.BrightstarEventId.ServerCoreException, "Error Executing Query {0} {1}", storeName,
queryExpression);
throw new BrightstarClientException(
"Error querying store " + storeName + " with expression " + queryExpression + ". " + ex.Message, ex);
}
}
public Stream ExecuteQuery(string storeName, string queryExpression, DateTime?ifNotModifiedSince, string resultsMediaType = null)
{
try
{
var resultsFormat = resultsMediaType == null ? SparqlResultsFormat.Xml : SparqlResultsFormat.GetResultsFormat(resultsMediaType);
/*
* var connStream = new ConnectionStream();
* var cStream = new ConsumerStream(connStream);
* var pStream = new ProducerStream(connStream);
*/
var pStream = new MemoryStream();
ServerCore.Query(storeName, queryExpression, ifNotModifiedSince, resultsFormat, pStream);
//var t = new Task(() => ServerCore.Query(storeName, queryExpression, ifNotModifiedSince, pStream));
//t.Start();
//t.Wait();
//if (t.IsFaulted && t.Exception != null) throw t.Exception;
var cStream = new MemoryStream(pStream.GetBuffer(), 0, (int)pStream.Length);
return(cStream);
}
catch (AggregateException aggregateException)
{
if (aggregateException.InnerException is BrightstarStoreNotModifiedException)
{
throw new BrightstarClientException("Store not modified", aggregateException.InnerException);
}
throw new BrightstarClientException("Error executing query", aggregateException.InnerException);
}
catch (BrightstarStoreNotModifiedException ex)
{
throw new BrightstarClientException("Store not modified", new ExceptionDetail(ex));
}
catch (Exception ex)
{
Logging.LogError(BrightstarDB.BrightstarEventId.ServerCoreException, "Error Executing Query {0} {1}", storeName,
queryExpression);
throw new BrightstarClientException(
"Error querying store " + storeName + " with expression " + queryExpression + ". " + ex.Message, ex);
}
}
public ActionResult Query(string storename, string query)
{
// Determine what results format to return to the client
string bestMimeType = MimeParse.MimeParse.BestMatch(SparqlResultsFormat.AllMediaTypes.ToList(),
Request.Headers["Accept"]);
var callback = Request["callback"];
if (!String.IsNullOrEmpty(callback) && Request.Headers["Accept"].Contains("*/*"))
{
// Workaround for jQuery clients that will send Accept */* for a JSONP request
bestMimeType = SparqlResultsFormat.Json.MediaTypes[0];
}
SparqlResultsFormat resultsFormat = null;
if (!String.IsNullOrEmpty(bestMimeType))
{
resultsFormat = SparqlResultsFormat.GetResultsFormat(bestMimeType);
}
if (resultsFormat == null)
{
throw new HttpException(406, "Not Acceptable");
}
if (query == null && Request.HttpMethod.ToLower().Equals("post") && Request.ContentType.Equals("application/sparql-query"))
{
try
{
string q;
using (var streamReader = new StreamReader(Request.InputStream))
{
q = streamReader.ReadToEnd();
if (string.IsNullOrEmpty(q))
{
throw new HttpException(400, "No query in request body");
}
}
// Execute the query
var client = BrightstarService.GetClient();
var results = client.ExecuteQuery(storename, q, DateTime.MinValue, resultsFormat);
return(new FileStreamResult(results, resultsFormat.ToString()));
}
catch (Exception ex)
{
throw new HttpException(500, "Unable to execute query " + ex.Message, ex);
}
}
if (query != null)
{
try
{
var client = BrightstarService.GetClient();
if (resultsFormat.DefaultExtension.Equals(SparqlResultsFormat.Json.DefaultExtension) && !String.IsNullOrEmpty(callback))
{
// Handle JSONP request
var results = client.ExecuteQuery(storename, query, DateTime.MinValue, resultsFormat);
using (var stringReader = new StreamReader(results))
{
var rawJson = stringReader.ReadToEnd();
return(new ContentResult
{
ContentType = bestMimeType,
Content = callback + "(" + rawJson + ");",
ContentEncoding = Encoding.UTF8
});
}
}
else
{
var results = client.ExecuteQuery(storename, query, DateTime.MinValue, resultsFormat);
return(new FileStreamResult(results, resultsFormat.ToString()));
}
}
catch (Exception ex)
{
throw new HttpException(500, "Unable to execute query " + ex.Message, ex);
}
}
MimeParse.MimeParse.BestMatch(new []
{
"application/xbel+xml",
"text/xml"
}, "text/*;q=0.5,*; q=0.1"); // 'text/xml'
throw new HttpException(400, "Missing parameters or incorrect request format");
}