Allow setting the seed argument for hash partition

java/src/main/java/ai/rapids/cudf/Table.java

@@ -194,6 +194,7 @@ private static native long[] hashPartition(long inputTable,
                                              int[] columnsToHash,
                                              int hashTypeId,
                                              int numberOfPartitions,
+                                             int seed,
                                              int[] outputOffsets) throws CudfException;
 
   private static native long[] roundRobinPartition(long inputTable,
@@ -4253,12 +4254,27 @@ public PartitionedTable hashPartition(int numberOfPartitions) {
      * {@link Table} class
      */
     public PartitionedTable hashPartition(HashType type, int numberOfPartitions) {
+      final int DEFAULT_HASH_SEED = 0;
+      return hashPartition(type, numberOfPartitions, DEFAULT_HASH_SEED);
+    }
+
+    /**
+     * Hash partition a table into the specified number of partitions.
+     * @param type the type of hash to use. Depending on the type of hash different restrictions
+     *             on the hash column(s) may exist. Not all hash functions are guaranteed to work
+     *             besides IDENTITY and MURMUR3.
+     * @param numberOfPartitions number of partitions to use
+     * @param seed the seed value for hashing
+     * @return Table that exposes a limited functionality of the {@link Table} class
+     */
+    public PartitionedTable hashPartition(HashType type, int numberOfPartitions, int seed) {
       int[] partitionOffsets = new int[numberOfPartitions];
       return new PartitionedTable(new Table(Table.hashPartition(
           operation.table.nativeHandle,
           operation.indices,
           type.nativeId,
           partitionOffsets.length,
+          seed,
           partitionOffsets)), partitionOffsets);
     }
   }

java/src/main/native/src/TableJni.cpp

@@ -2655,7 +2655,7 @@ JNIEXPORT jlongArray JNICALL Java_ai_rapids_cudf_Table_partition(JNIEnv *env, jc
 
 JNIEXPORT jlongArray JNICALL Java_ai_rapids_cudf_Table_hashPartition(
     JNIEnv *env, jclass, jlong input_table, jintArray columns_to_hash, jint hash_function,
-    jint number_of_partitions, jintArray output_offsets) {
+    jint number_of_partitions, jint seed, jintArray output_offsets) {
 
   JNI_NULL_CHECK(env, input_table, "input table is null", NULL);
   JNI_NULL_CHECK(env, columns_to_hash, "columns_to_hash is null", NULL);
@@ -2665,15 +2665,16 @@ JNIEXPORT jlongArray JNICALL Java_ai_rapids_cudf_Table_hashPartition(
   try {
     cudf::jni::auto_set_device(env);
     auto const hash_func = static_cast<cudf::hash_id>(hash_function);
+    auto const hash_seed = static_cast<uint32_t>(seed);
     auto const n_input_table = reinterpret_cast<cudf::table_view const *>(input_table);
     cudf::jni::native_jintArray n_columns_to_hash(env, columns_to_hash);
     JNI_ARG_CHECK(env, n_columns_to_hash.size() > 0, "columns_to_hash is zero", NULL);
 
     std::vector<cudf::size_type> columns_to_hash_vec(n_columns_to_hash.begin(),
                                                      n_columns_to_hash.end());
 
-    auto [partitioned_table, partition_offsets] =
-        cudf::hash_partition(*n_input_table, columns_to_hash_vec, number_of_partitions, hash_func);
+    auto [partitioned_table, partition_offsets] = cudf::hash_partition(
+        *n_input_table, columns_to_hash_vec, number_of_partitions, hash_func, hash_seed);
 
     cudf::jni::native_jintArray n_output_offsets(env, output_offsets);
     std::copy(partition_offsets.begin(), partition_offsets.end(), n_output_offsets.begin());