[jvm-packages] add Rapids plugin support

jvm-packages/pom.xml

@@ -34,13 +34,16 @@
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
         <flink.version>1.7.2</flink.version>
-        <spark.version>3.0.0</spark.version>
+        <spark.version>3.0.1</spark.version>
         <scala.version>2.12.8</scala.version>
         <scala.binary.version>2.12</scala.binary.version>
         <hadoop.version>2.7.3</hadoop.version>
         <maven.wagon.http.retryHandler.count>5</maven.wagon.http.retryHandler.count>
         <log.capi.invocation>OFF</log.capi.invocation>
         <use.cuda>OFF</use.cuda>
+        <cudf.version>21.08.2</cudf.version>
+        <spark.rapids.version>21.08.0</spark.rapids.version>
+        <cudf.classifier>cuda11</cudf.classifier>
     </properties>
     <repositories>
         <repository>

jvm-packages/xgboost4j-gpu/pom.xml

@@ -12,11 +12,6 @@
     <version>1.6.0-SNAPSHOT</version>
     <packaging>jar</packaging>
 
-    <properties>
-      <cudf.version>21.08.2</cudf.version>
-      <cudf.classifier>cuda11</cudf.classifier>
-    </properties>
-
     <dependencies>
         <dependency>
           <groupId>ai.rapids</groupId>

jvm-packages/xgboost4j-spark-gpu/pom.xml

@@ -44,5 +44,18 @@
             <version>${spark.version}</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+          <groupId>ai.rapids</groupId>
+          <artifactId>cudf</artifactId>
+          <version>${cudf.version}</version>
+          <classifier>${cudf.classifier}</classifier>
+          <scope>provided</scope>
+        </dependency>
+        <dependency>
+          <groupId>com.nvidia</groupId>
+          <artifactId>rapids-4-spark_${scala.binary.version}</artifactId>
+          <version>${spark.rapids.version}</version>
+          <scope>provided</scope>
+        </dependency>
     </dependencies>
 </project>

jvm-packages/xgboost4j-spark-gpu/src/main/java/ml/dmlc/xgboost4j/java/nvidia/spark/GpuColumnBatch.java

@@ -0,0 +1,68 @@
+/*
+ Copyright (c) 2021 by Contributors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+package ml.dmlc.xgboost4j.java.nvidia.spark;
+
+import java.util.List;
+
+import ai.rapids.cudf.ColumnVector;
+import ai.rapids.cudf.Table;
+import org.apache.spark.sql.types.*;
+
+/**
+ * Wrapper of CudfTable with schema for scala
+ */
+public class GpuColumnBatch implements AutoCloseable {
+  private final StructType schema;
+  private Table table; // the original Table
+
+  public GpuColumnBatch(Table table, StructType schema) {
+    this.table = table;
+    this.schema = schema;
+  }
+
+  @Override
+  public void close() {
+    if (table != null) {
+      table.close();
+      table = null;
+    }
+  }
+
+  /** Slice the columns indicated by indices into a Table*/
+  public Table slice(List<Integer> indices) {
+    if (indices == null || indices.size() == 0) {
+      return null;
+    }
+
+    int len = indices.size();
+    ColumnVector[] cv = new ColumnVector[len];
+    for (int i = 0; i < len; i++) {
+      int index = indices.get(i);
+      if (index >= table.getNumberOfColumns()) {
+        throw new RuntimeException("Wrong index");
+      }
+      cv[i] = table.getColumn(index);
+    }
+
+    return new Table(cv);
+  }
+
+  public StructType getSchema() {
+    return schema;
+  }
+
+}

jvm-packages/xgboost4j-spark-gpu/src/main/resources/META-INF/services/ml.dmlc.xgboost4j.scala.spark.PreXGBoostProvider

@@ -0,0 +1 @@
+ml.dmlc.xgboost4j.scala.rapids.spark.GpuPreXGBoost