add TupleUtils class

heron/storm/src/java/org/apache/storm/Constants.java

@@ -0,0 +1,27 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.storm;
+
+public final class Constants {
+
+  private Constants() {
+  }
+
+  public static final String SYSTEM_COMPONENT_ID = "__system";
+  public static final String SYSTEM_TICK_STREAM_ID = "__tick";
+}

heron/storm/src/java/org/apache/storm/utils/TupleUtils.java

@@ -0,0 +1,57 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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 org.apache.storm.utils;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.storm.Config;
+import org.apache.storm.Constants;
+import org.apache.storm.tuple.Tuple;
+
+public final class TupleUtils {
+
+  private TupleUtils() {
+    // No instantiation
+  }
+
+  public static boolean isTick(Tuple tuple) {
+    return tuple != null
+        && Constants.SYSTEM_COMPONENT_ID.equals(tuple.getSourceComponent())
+        && Constants.SYSTEM_TICK_STREAM_ID.equals(tuple.getSourceStreamId());
+  }
+
+  public static <T> int listHashCode(List<T> alist) {
+    if (alist == null) {
+      return 1;
+    } else {
+      return Arrays.deepHashCode(alist.toArray());
+    }
+  }
+
+  public static Map<String, Object> putTickFrequencyIntoComponentConfig(Map<String, Object> conf,
+                                                                        int tickFreqSecs) {
+    if (conf != null && tickFreqSecs > 0) {
+      conf.put(Config.TOPOLOGY_TICK_TUPLE_FREQ_SECS, tickFreqSecs);
+    }
+
+    return conf;
+  }
+
+}