Flink writer single file/sorted output options added.

Author: LorenzBuehmann

sansa-inference-flink/src/main/scala/net/sansa_stack/inference/flink/RDFGraphMaterializer.scala

@@ -57,7 +57,7 @@ object RDFGraphMaterializer {
     println(s"|G_inf| = ${inferredGraph.size()}")
 
     // write triples to disk
-    RDFGraphWriter.writeToDisk(inferredGraph, output)
+    RDFGraphWriter.writeToDisk(inferredGraph, output, writeToSingleFile, sortedOutput)
 
 //    println(env.getExecutionPlan())
 

sansa-inference-flink/src/main/scala/net/sansa_stack/inference/flink/data/RDFGraphWriter.scala

@@ -33,7 +33,15 @@ object RDFGraphWriter {
     logger.info("finished writing triples to disk in " + (System.currentTimeMillis()-startTime) + "ms.")
   }
 
-  def writeToDisk(graph: RDFGraph, path: File): Unit = {
+  /**
+    * Write the graph to disk in N-Triple format.
+    *
+    * @param graph the RDF graph
+    * @param path the output  directory
+    * @param singleFile whether to put all data into a single file
+    * @param sorted whether to sort the triples by subject, predicate, object
+    */
+  def writeToDisk(graph: RDFGraph, path: File, singleFile: Boolean = false, sorted: Boolean = false): Unit = {
     logger.info("writing triples to disk...")
     val startTime  = System.currentTimeMillis()