added copyright text to Timestamped class, added timestamp operation, reusing mapping

Author: jmhofer

rxjava-core/src/main/java/rx/operators/OperationTimestamp.java

@@ -0,0 +1,43 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ * 
+ * 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 rx.operators;
+
+import rx.Observable;
+import rx.Observer;
+import rx.Subscription;
+import rx.util.Timestamped;
+import rx.util.functions.Func1;
+
+public final class OperationTimestamp {
+
+    /**
+     * Accepts a sequence and adds timestamps to each item in it.
+     * 
+     * @param sequence
+     *            the input sequence.
+     * @param <T>
+     *            the type of the input sequence.
+     * @return a sequence of timestamped values created by adding timestamps to each item in the input sequence.
+     */
+    public static <T> Func1<Observer<Timestamped<T>>, Subscription> timestamp(Observable<T> sequence) {
+        return OperationMap.map(sequence, new Func1<T, Timestamped<T>>() {
+            @Override
+            public Timestamped<T> call(T value) {
+                return new Timestamped<T>(System.currentTimeMillis(), value);
+            }
+        });
+    }
+}

rxjava-core/src/main/java/rx/util/Timestamped.java

@@ -1,3 +1,18 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ * 
+ * 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 rx.util;
 
 /**