1.x: benchmark reduce and takeLast(1) (#4174)

* 1.x: benchmark reduce and takeLast(1)

* add collect() benchmark

Author: akarnokd

src/perf/java/rx/DeferredScalarPerf.java

@@ -0,0 +1,106 @@
+/**
+ * Copyright 2016 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;
+
+import java.util.Arrays;
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+
+import rx.functions.*;
+import rx.jmh.LatchedObserver;
+
+/**
+ * Benchmark operators that consume their sources completely and signal a single value.
+ * <p>
+ * gradlew benchmarks "-Pjmh=-f 1 -tu s -bm thrpt -wi 5 -i 5 -r 1 .*DeferredScalarPerf.*"
+ * <p>
+ * gradlew benchmarks "-Pjmh=-f 1 -tu ns -bm avgt -wi 5 -i 5 -r 1 .*DeferredScalarPerf.*"
+ */
+@BenchmarkMode(Mode.Throughput)
+@OutputTimeUnit(TimeUnit.SECONDS)
+@State(Scope.Thread)
+public class DeferredScalarPerf {
+
+    @Param({"1", "10", "100", "1000", "10000", "100000", "1000000"})
+    public int count;
+
+    Observable<Integer> last;
+
+    Observable<Integer> reduce;
+
+    Observable<Integer> reduceSeed;
+    
+    Observable<int[]> collect;
+
+    @Setup
+    public void setup() {
+        Integer[] array = new Integer[count];
+        Arrays.fill(array, 777);
+        
+        Observable<Integer> source = Observable.from(array);
+        
+        reduce = source.reduce(new Func2<Integer, Integer, Integer>() {
+            @Override
+            public Integer call(Integer a, Integer b) {
+                return b;
+            }
+        });
+        reduceSeed = source.reduce(0, new Func2<Integer, Integer, Integer>() {
+            @Override
+            public Integer call(Integer a, Integer b) {
+                return b;
+            }
+        });
+        
+        last = source.takeLast(1);
+        
+        collect = source.collect(new Func0<int[]>() {
+            @Override
+            public int[] call() {
+                return new int[1];
+            }
+        }, new Action2<int[], Integer>() {
+            @Override
+            public void call(int[] a, Integer b) { 
+                a[0] = b.intValue(); 
+            }
+        } );
+    }
+    
+//    @Benchmark
+    public void reduce(Blackhole bh) {
+        reduce.subscribe(new LatchedObserver<Integer>(bh));
+    }
+
+//    @Benchmark
+    public void reduceSeed(Blackhole bh) {
+        reduceSeed.subscribe(new LatchedObserver<Integer>(bh));
+    }
+
+//    @Benchmark
+    public void last(Blackhole bh) {
+        last.subscribe(new LatchedObserver<Integer>(bh));
+    }
+
+    @Benchmark
+    public void collect(Blackhole bh) {
+        collect.subscribe(new LatchedObserver<int[]>(bh));
+    }
+
+}