revise current API

dmlc-core

@@ -1 +1 @@
-Subproject commit 969fb6455ae41d5d2f7c4ba8921f4885e9aa63c8
+Subproject commit 4e6459b0bc15e6cf9b315cc75e2e5495c03cd417

jvm-packages/xgboost4j-example/src/main/scala/ml/dmlc/xgboost4j/scala/spark/example/DistTrainWithSpark.scala

@@ -38,8 +38,8 @@ object DistTrainWithSpark {
       "eta" -> 0.1f,
       "max_depth" -> 2,
       "objective" -> "binary:logistic").toMap
-    val model = XGBoost.train(trainRDD, paramMap, numRound)
+    val xgboostModel = XGBoost.train(trainRDD, paramMap, numRound)
     // save model to HDFS path
-    model.saveModelToHadoop(outputModelPath)
+    xgboostModel.saveModelToHadoop(outputModelPath)
   }
 }

jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoost.scala

@@ -19,23 +19,21 @@ package ml.dmlc.xgboost4j.scala.spark
 import scala.collection.mutable
 import scala.collection.JavaConverters._
 
-
-import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.{Path, FileSystem}
 
 import org.apache.commons.logging.LogFactory
-import org.apache.spark.TaskContext
+import org.apache.spark.{SparkContext, TaskContext}
 import org.apache.spark.mllib.regression.LabeledPoint
 import org.apache.spark.rdd.RDD
 
-import ml.dmlc.xgboost4j.java.{DMatrix => JDMatrix, Rabit, RabitTracker}
+import ml.dmlc.xgboost4j.java.{DMatrix => JDMatrix, XGBoostError, Rabit, RabitTracker}
 import ml.dmlc.xgboost4j.scala.{XGBoost => SXGBoost, _}
 
 object XGBoost extends Serializable {
-  var boosters: RDD[Booster] = null
   private val logger = LogFactory.getLog("XGBoostSpark")
 
-  implicit def convertBoosterToXGBoostModel(booster: Booster): XGBoostModel = {
+  private implicit def convertBoosterToXGBoostModel(booster: Booster)
+      (implicit sc: SparkContext): XGBoostModel = {
     new XGBoostModel(booster)
   }
 
@@ -57,27 +55,36 @@ object XGBoost extends Serializable {
     }.cache()
   }
 
+  /**
+   *
+   * @param trainingData the trainingset represented as RDD
+   * @param configMap Map containing the configuration entries
+   * @param round the number of iterations
+   * @param obj the user-defined objective function, null by default
+   * @param eval the user-defined evaluation function, null by default
+   * @throws ml.dmlc.xgboost4j.java.XGBoostError when the model training is failed
+   * @return XGBoostModel when successful training
+   */
+  @throws(classOf[XGBoostError])
   def train(trainingData: RDD[LabeledPoint], configMap: Map[String, Any], round: Int,
        obj: ObjectiveTrait = null, eval: EvalTrait = null): XGBoostModel = {
     val numWorkers = trainingData.partitions.length
-    val sc = trainingData.sparkContext
+    implicit val sc = trainingData.sparkContext
     val tracker = new RabitTracker(numWorkers)
     require(tracker.start(), "FAULT: Failed to start tracker")
     val boosters = buildDistributedBoosters(trainingData, configMap,
       tracker.getWorkerEnvs.asScala, numWorkers, round, obj, eval)
-    @volatile var booster: Booster = null
     val sparkJobThread = new Thread() {
       override def run() {
         // force the job
-        boosters.foreachPartition(_ => ())
+        boosters.foreachPartition(() => _)
       }
     }
     sparkJobThread.start()
     val returnVal = tracker.waitFor()
     logger.info(s"Rabit returns with exit code $returnVal")
     if (returnVal == 0) {
-      booster = boosters.first()
+      boosters.first()
-      Some(booster).get
     } else {
       try {
         if (sparkJobThread.isAlive) {
@@ -87,21 +94,20 @@ object XGBoost extends Serializable {
         case ie: InterruptedException =>
           logger.info("spark job thread is interrupted")
       }
-      null
+      throw new XGBoostError("XGBoostModel training failed")
     }
   }
 
   /**
-    * Load XGBoost model from path, using Hadoop Filesystem API.
+   * Load XGBoost model from path in HDFS-compatible file system
-    *
+   *
-    * @param modelPath The path that is accessible by hadoop filesystem API.
+   * @param modelPath The path of the file representing the model
-    * @return The loaded model
+   * @return The loaded model
-    */
+   */
-  def loadModelFromHadoop(modelPath: String) : XGBoostModel = {
+  def loadModelFromHadoop(modelPath: String)(implicit sparkContext: SparkContext): XGBoostModel = {
-    new XGBoostModel(
+    val dataInStream = FileSystem.get(sparkContext.hadoopConfiguration).open(new Path(modelPath))
-      SXGBoost.loadModel(
+    val xgBoostModel = new XGBoostModel(SXGBoost.loadModel(dataInStream))
-        FileSystem
+    dataInStream.close()
-          .get(new Configuration)
+    xgBoostModel
-          .open(new Path(modelPath))))
   }
 }

jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostModel.scala

@@ -16,18 +16,17 @@
 
 package ml.dmlc.xgboost4j.scala.spark
 
-import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.{Path, FileSystem}
+import org.apache.spark.SparkContext
 import org.apache.spark.mllib.linalg.Vector
 import org.apache.spark.rdd.RDD
 import ml.dmlc.xgboost4j.java.{DMatrix => JDMatrix}
 import ml.dmlc.xgboost4j.scala.{DMatrix, Booster}
 
-class XGBoostModel(booster: Booster) extends Serializable {
+class XGBoostModel(booster: Booster)(implicit val sc: SparkContext) extends Serializable {
+
   /**
-    * Predict result given testRDD
+    * Predict result with the given testset (represented as RDD)
-    * @param testSet the testSet of Data vectors
-    * @return The predicted RDD
     */
   def predict(testSet: RDD[Vector]): RDD[Array[Array[Float]]] = {
     import DataUtils._
@@ -39,18 +38,21 @@ class XGBoostModel(booster: Booster) extends Serializable {
     }
   }
 
+  /**
+   * predict result given the test data (represented as DMatrix)
+   */
   def predict(testSet: DMatrix): Array[Array[Float]] = {
-    booster.predict(testSet)
+    booster.predict(testSet, true, 0)
   }
 
   /**
-    * Save the model as a Hadoop filesystem file.
+    * Save the model as to HDFS-compatible file system.
-    *
+ *
     * @param modelPath The model path as in Hadoop path.
     */
   def saveModelToHadoop(modelPath: String): Unit = {
-    booster.saveModel(FileSystem
+    val outputStream = FileSystem.get(sc.hadoopConfiguration).create(new Path(modelPath))
-      .get(new Configuration)
+    booster.saveModel(outputStream)
-      .create(new Path(modelPath)))
+    outputStream.close()
   }
 }

jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostSuite.scala

@@ -17,13 +17,11 @@
 package ml.dmlc.xgboost4j.scala.spark
 
 import java.io.File
+import java.nio.file.Files
 
 import scala.collection.mutable.ListBuffer
 import scala.io.Source
-import scala.tools.reflect.Eval
 
-import ml.dmlc.xgboost4j.java.{DMatrix => JDMatrix, XGBoostError}
-import ml.dmlc.xgboost4j.scala.{DMatrix, EvalTrait}
 import org.apache.commons.logging.LogFactory
 import org.apache.spark.mllib.linalg.DenseVector
 import org.apache.spark.mllib.regression.LabeledPoint
@@ -31,10 +29,13 @@ import org.apache.spark.rdd.RDD
 import org.apache.spark.{SparkConf, SparkContext}
 import org.scalatest.{BeforeAndAfterAll, FunSuite}
 
+import ml.dmlc.xgboost4j.java.{DMatrix => JDMatrix, XGBoostError}
+import ml.dmlc.xgboost4j.scala.{DMatrix, EvalTrait}
+
 class XGBoostSuite extends FunSuite with BeforeAndAfterAll {
 
-  private var sc: SparkContext = null
+  private implicit var sc: SparkContext = null
-  private val numWorker = 4
+  private val numWorker = 2
 
   private class EvalError extends EvalTrait {
 
@@ -111,14 +112,9 @@ class XGBoostSuite extends FunSuite with BeforeAndAfterAll {
     sampleList.toList
   }
 
-  private def buildRDD(filePath: String): RDD[LabeledPoint] = {
-    val sampleList = readFile(filePath)
-    sc.parallelize(sampleList, numWorker)
-  }
-
   private def buildTrainingRDD(): RDD[LabeledPoint] = {
-    val trainRDD = buildRDD(getClass.getResource("/agaricus.txt.train").getFile)
+    val sampleList = readFile(getClass.getResource("/agaricus.txt.train").getFile)
-    trainRDD
+    sc.parallelize(sampleList, numWorker)
   }
 
   test("build RDD containing boosters") {
@@ -140,4 +136,23 @@ class XGBoostSuite extends FunSuite with BeforeAndAfterAll {
       assert(new EvalError().eval(predicts, testSetDMatrix) < 0.1)
     }
   }
+
+
+  test("save and load model") {
+    val eval = new EvalError()
+    val trainingRDD = buildTrainingRDD()
+    val testSet = readFile(getClass.getResource("/agaricus.txt.test").getFile).iterator
+    import DataUtils._
+    val testSetDMatrix = new DMatrix(new JDMatrix(testSet, null))
+    val tempDir = Files.createTempDirectory("xgboosttest-")
+    val tempFile = Files.createTempFile(tempDir, "", "")
+    val paramMap = List("eta" -> "1", "max_depth" -> "2", "silent" -> "0",
+      "objective" -> "binary:logistic").toMap
+    val xgBoostModel = XGBoost.train(trainingRDD, paramMap, 5)
+    assert(eval.eval(xgBoostModel.predict(testSetDMatrix), testSetDMatrix) < 0.1)
+    xgBoostModel.saveModelToHadoop(tempFile.toFile.getAbsolutePath)
+    val loadedXGBooostModel = XGBoost.loadModelFromHadoop(tempFile.toFile.getAbsolutePath)
+    val predicts = loadedXGBooostModel.predict(testSetDMatrix)
+    assert(eval.eval(predicts, testSetDMatrix) < 0.1)
+  }
 }

jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/RabitTracker.java

@@ -129,6 +129,7 @@ public class RabitTracker {
   public boolean start() {
     if (startTrackerProcess()) {
       logger.debug("Tracker started, with env=" + envs.toString());
+      System.out.println("Tracker started, with env=" + envs.toString());
       // also start a tracker logger
       Thread logger_thread = new Thread(new TrackerProcessLogger());
       logger_thread.setDaemon(true);

jvm-packages/xgboost4j/src/main/scala/ml/dmlc/xgboost4j/scala/Booster.scala

@@ -119,7 +119,7 @@ class Booster private[xgboost4j](booster: JBooster) extends Serializable {
    */
   @throws(classOf[XGBoostError])
   def predict(data: DMatrix, outPutMargin: Boolean = false, treeLimit: Int = 0)
-    : Array[Array[Float]] = {
+      : Array[Array[Float]] = {
     booster.predict(data.jDMatrix, outPutMargin, treeLimit)
   }
 
@@ -178,6 +178,10 @@ class Booster private[xgboost4j](booster: JBooster) extends Serializable {
     booster.getFeatureScore(featureMap).asScala
   }
 
+  def toByteArray: Array[Byte] = {
+    booster.toByteArray
+  }
+
   /**
     *  Dispose the booster when it is no longer needed
     */

jvm-packages/xgboost4j/src/test/java/ml/dmlc/xgboost4j/java/BoosterImplTest.java

@@ -17,7 +17,10 @@ package ml.dmlc.xgboost4j.java;
 
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
@@ -70,11 +73,7 @@ public class BoosterImplTest {
     }
   }
 
-  @Test
+  private Booster trainBooster(DMatrix trainMat, DMatrix testMat) throws XGBoostError {
-  public void testBoosterBasic() throws XGBoostError, IOException {
-    DMatrix trainMat = new DMatrix("../../demo/data/agaricus.txt.train");
-    DMatrix testMat = new DMatrix("../../demo/data/agaricus.txt.test");
-
     //set params
     Map<String, Object> paramMap = new HashMap<String, Object>() {
       {
@@ -92,10 +91,19 @@ public class BoosterImplTest {
     watches.put("test", testMat);
 
     //set round
-    int round = 2;
+    int round = 5;
 
     //train a boost model
-    Booster booster = XGBoost.train(paramMap, trainMat, round, watches, null, null);
+    return XGBoost.train(paramMap, trainMat, round, watches, null, null);
+  }
+
+  @Test
+  public void testBoosterBasic() throws XGBoostError, IOException {
+
+    DMatrix trainMat = new DMatrix("../../demo/data/agaricus.txt.train");
+    DMatrix testMat = new DMatrix("../../demo/data/agaricus.txt.test");
+
+    Booster booster = trainBooster(trainMat, testMat);
 
     //predict raw output
     float[][] predicts = booster.predict(testMat, true, 0);
@@ -104,14 +112,43 @@ public class BoosterImplTest {
     IEvaluation eval = new EvalError();
     //error must be less than 0.1
     TestCase.assertTrue(eval.eval(predicts, testMat) < 0.1f);
+  }
 
+  @Test
+  public void saveLoadModelWithPath() throws XGBoostError, IOException {
+    DMatrix trainMat = new DMatrix("../../demo/data/agaricus.txt.train");
+    DMatrix testMat = new DMatrix("../../demo/data/agaricus.txt.test");
+    IEvaluation eval = new EvalError();
+
+    Booster booster = trainBooster(trainMat, testMat);
     // save and load
     File temp = File.createTempFile("temp", "model");
     temp.deleteOnExit();
     booster.saveModel(temp.getAbsolutePath());
 
-    Booster bst2 = XGBoost.loadModel(new FileInputStream(temp.getAbsolutePath()));
+    Booster bst2 = XGBoost.loadModel(temp.getAbsolutePath());
     assert (Arrays.equals(bst2.toByteArray(), booster.toByteArray()));
+    float[][] predicts2 = bst2.predict(testMat, true, 0);
+    TestCase.assertTrue(eval.eval(predicts2, testMat) < 0.1f);
+  }
+
+  @Test
+  public void saveLoadModelWithStream() throws XGBoostError, IOException {
+    DMatrix trainMat = new DMatrix("../../demo/data/agaricus.txt.train");
+    DMatrix testMat = new DMatrix("../../demo/data/agaricus.txt.test");
+
+    Booster booster = trainBooster(trainMat, testMat);
+
+    Path tempDir = Files.createTempDirectory("boosterTest-");
+    File tempFile = Files.createTempFile("", "").toFile();
+    booster.saveModel(new FileOutputStream(tempFile));
+    IEvaluation eval = new EvalError();
+    Booster loadedBooster = XGBoost.loadModel(new FileInputStream(tempFile));
+    float originalPredictError = eval.eval(booster.predict(testMat, true), testMat);
+    TestCase.assertTrue("originalPredictErr:" + originalPredictError,
+            originalPredictError < 0.1f);
+    float loadedPredictError = eval.eval(loadedBooster.predict(testMat, true), testMat);
+    TestCase.assertTrue("loadedPredictErr:" + loadedPredictError, loadedPredictError < 0.1f);
   }
 
   /**

jvm-packages/xgboost4j/src/test/scala/ml/dmlc/xgboost4j/scala/ScalaBoosterImplSuite.scala

@@ -16,10 +16,14 @@
 
 package ml.dmlc.xgboost4j.scala
 
-import ml.dmlc.xgboost4j.java.XGBoostError
+import java.io.{FileOutputStream, FileInputStream, File}
+
+import junit.framework.TestCase
 import org.apache.commons.logging.LogFactory
 import org.scalatest.FunSuite
 
+import ml.dmlc.xgboost4j.java.XGBoostError
+
 class ScalaBoosterImplSuite extends FunSuite {
 
   private class EvalError extends EvalTrait {
@@ -64,21 +68,58 @@ class ScalaBoosterImplSuite extends FunSuite {
     }
   }
 
-  test("basic operation of booster") {
+  private def trainBooster(trainMat: DMatrix, testMat: DMatrix): Booster = {
-    val trainMat = new DMatrix("../../demo/data/agaricus.txt.train")
-    val testMat = new DMatrix("../../demo/data/agaricus.txt.test")
-
     val paramMap = List("eta" -> "1", "max_depth" -> "2", "silent" -> "1",
       "objective" -> "binary:logistic").toMap
     val watches = List("train" -> trainMat, "test" -> testMat).toMap
 
     val round = 2
-    val booster = XGBoost.train(paramMap, trainMat, round, watches, null, null)
+    XGBoost.train(paramMap, trainMat, round, watches, null, null)
+  }
+
+  test("basic operation of booster") {
+    val trainMat = new DMatrix("../../demo/data/agaricus.txt.train")
+    val testMat = new DMatrix("../../demo/data/agaricus.txt.test")
+
+    val booster = trainBooster(trainMat, testMat)
     val predicts = booster.predict(testMat, true)
     val eval = new EvalError
     assert(eval.eval(predicts, testMat) < 0.1)
   }
 
+  test("save/load model with path") {
+
+    val trainMat = new DMatrix("../../demo/data/agaricus.txt.train")
+    val testMat = new DMatrix("../../demo/data/agaricus.txt.test")
+    val eval = new EvalError
+    val booster = trainBooster(trainMat, testMat)
+    // save and load
+    val temp: File = File.createTempFile("temp", "model")
+    temp.deleteOnExit()
+    booster.saveModel(temp.getAbsolutePath)
+
+    val bst2: Booster = XGBoost.loadModel(temp.getAbsolutePath)
+    assert(java.util.Arrays.equals(bst2.toByteArray, booster.toByteArray))
+    val predicts2: Array[Array[Float]] = bst2.predict(testMat, true, 0)
+    TestCase.assertTrue(eval.eval(predicts2, testMat) < 0.1f)
+  }
+
+  test("save/load model with stream") {
+    val trainMat = new DMatrix("../../demo/data/agaricus.txt.train")
+    val testMat = new DMatrix("../../demo/data/agaricus.txt.test")
+    val eval = new EvalError
+    val booster = trainBooster(trainMat, testMat)
+    // save and load
+    val temp: File = File.createTempFile("temp", "model")
+    temp.deleteOnExit()
+    booster.saveModel(new FileOutputStream(temp.getAbsolutePath))
+
+    val bst2: Booster = XGBoost.loadModel(new FileInputStream(temp.getAbsolutePath))
+    assert(java.util.Arrays.equals(bst2.toByteArray, booster.toByteArray))
+    val predicts2: Array[Array[Float]] = bst2.predict(testMat, true, 0)
+    TestCase.assertTrue(eval.eval(predicts2, testMat) < 0.1f)
+  }
+
   test("cross validation") {
     val trainMat = new DMatrix("../../demo/data/agaricus.txt.train")
     val params = List("eta" -> "1.0", "max_depth" -> "3", "slient" -> "1", "nthread" -> "6",