1 /*
   2  * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.openjdk.bench.java.util.stream.ops.ref;
  24 
  25 import org.openjdk.bench.java.util.stream.ops.LongAccumulator;
  26 import org.openjdk.jmh.annotations.Benchmark;
  27 import org.openjdk.jmh.annotations.BenchmarkMode;
  28 import org.openjdk.jmh.annotations.Mode;
  29 import org.openjdk.jmh.annotations.OutputTimeUnit;
  30 import org.openjdk.jmh.annotations.Param;
  31 import org.openjdk.jmh.annotations.Scope;
  32 import org.openjdk.jmh.annotations.State;
  33 
  34 import java.util.concurrent.TimeUnit;
  35 import java.util.stream.LongStream;
  36 
  37 /**
  38  * Benchmark for limit() operation.
  39  */
  40 @BenchmarkMode(Mode.Throughput)
  41 @OutputTimeUnit(TimeUnit.SECONDS)
  42 @State(Scope.Thread)
  43 public class Limit {
  44 
  45     /**
  46      * Implementation notes:
  47      *   - parallel version requires thread-safe sink, we use the same for sequential version for better comparison
  48      *   - operations are explicit inner classes to untangle unwanted lambda effects
  49      *   - the tests include:
  50      *          - return nothing
  51      *          - return just a single element
  52      *          - return half
  53      *          - return all but last element
  54      *          - return all
  55      */
  56 
  57     @Param("100000")
  58     private int size;
  59 
  60     @Benchmark
  61     public long seq_baseline() {
  62         return LongStream.range(0, size)
  63                 .boxed()
  64                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
  65     }
  66 
  67     @Benchmark
  68     public long seq_limit0() {
  69         return LongStream.range(0, size)
  70                 .boxed()
  71                 .limit(0)
  72                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
  73     }
  74 
  75     @Benchmark
  76     public long seq_limit1() {
  77         return LongStream.range(0, size)
  78                 .boxed()
  79                 .limit(1)
  80                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
  81     }
  82 
  83     @Benchmark
  84     public long seq_limitHalf() {
  85         return LongStream.range(0, size)
  86                 .boxed()
  87                 .limit(size / 2)
  88                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
  89     }
  90 
  91     @Benchmark
  92     public long seq_limitFull() {
  93         return LongStream.range(0, size)
  94                 .boxed()
  95                 .limit(size - 1)
  96                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
  97     }
  98 
  99     @Benchmark
 100     public long seq_limitFullest() {
 101         return LongStream.range(0, size)
 102                 .boxed()
 103                 .limit(size)
 104                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
 105     }
 106 
 107     @Benchmark
 108     public long par_baseline() {
 109         return LongStream.range(0, size).parallel()
 110                 .boxed()
 111                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
 112     }
 113 
 114     @Benchmark
 115     public long par_limit0() {
 116         return LongStream.range(0, size).parallel()
 117                 .boxed()
 118                 .limit(0)
 119                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
 120     }
 121 
 122     @Benchmark
 123     public long par_limit1() {
 124         return LongStream.range(0, size).parallel()
 125                 .boxed()
 126                 .limit(1)
 127                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
 128     }
 129 
 130     @Benchmark
 131     public long par_limitHalf() {
 132         return LongStream.range(0, size).parallel()
 133                 .boxed()
 134                 .limit(size / 2)
 135                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
 136     }
 137 
 138     @Benchmark
 139     public long par_limitFull() {
 140         return LongStream.range(0, size).parallel()
 141                 .boxed().limit(size - 1)
 142                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
 143     }
 144 
 145     @Benchmark
 146     public long par_limitFullest() {
 147         return LongStream.range(0, size).parallel()
 148                 .boxed()
 149                 .limit(size)
 150                 .collect(LongAccumulator::new, LongAccumulator::add, LongAccumulator::merge).get();
 151     }
 152 
 153 }