Load `nweight-user-features` as resource file

[jnsrnhld]

Hi,

I wondered why the sparkbench/graph resource nweight-user-features is not loaded as a resource. The resource is packaged together with the .jar anyway, so I'd propose something like this:

NWeightDataGenerator.scala

[...]
def loadModel(modelPath: String, sc: SparkContext, partitions: Int): MatrixFactorizationModel = {
    getClass.getResourceAsStream(modelPath) match {
      case null => throw new FileNotFoundException(modelPath)
      case stream =>
        val in = new DataInputStream(stream)
        val weights = new Array[(Int, Double)](MAX_ID)
        for (i <- weights.indices) {
          val w = in.readFloat()
          weights(i) = (i, w)
        }
        in.close()

        val userFeatures = sc.parallelize(weights, math.max(400, partitions)).map { case (i, w) =>
          (i, Array(w))
        }
        val userFeaturesPartitioned = userFeatures.partitionBy(new HashPartitioner(partitions))
        userFeaturesPartitioned.cache()
        // Model matrix is symmetric, so productFeatures is the same with userFeatures
        new MatrixFactorizationModel(1, userFeaturesPartitioned, userFeaturesPartitioned)
    }
 }
[...]

and the workload config:

nweight.conf

[...]
hibench.nweight.model_path	            /nweight-user-features
[...]

This could be beneficial in cases where the execution environment does not contain the hibench directory itself.