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src/java.base/share/classes/java/util/IntSummaryStatistics.java

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rev 55098 : [mq]: 8224716-Javadoc-of-Int-Long-DoubleSummaryStatistics-should-mention-possible-overflow-of-count
   1 /*
   2  * Copyright (c) 2012, 2017, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any


  42  *
  43  * <p>{@code IntSummaryStatistics} can be used as a
  44  * {@linkplain java.util.stream.Stream#collect(Collector) reduction}
  45  * target for a {@linkplain java.util.stream.Stream stream}. For example:
  46  *
  47  * <pre> {@code
  48  * IntSummaryStatistics stats = people.stream()
  49  *                                    .collect(Collectors.summarizingInt(Person::getDependents));
  50  *}</pre>
  51  *
  52  * This computes, in a single pass, the count of people, as well as the minimum,
  53  * maximum, sum, and average of their number of dependents.
  54  *
  55  * @implNote This implementation is not thread safe. However, it is safe to use
  56  * {@link java.util.stream.Collectors#summarizingInt(java.util.function.ToIntFunction)
  57  * Collectors.summarizingInt()} on a parallel stream, because the parallel
  58  * implementation of {@link java.util.stream.Stream#collect Stream.collect()}
  59  * provides the necessary partitioning, isolation, and merging of results for
  60  * safe and efficient parallel execution.
  61  *
  62  * <p>This implementation does not check for overflow of the sum.
  63  * @since 1.8
  64  */
  65 public class IntSummaryStatistics implements IntConsumer {
  66     private long count;
  67     private long sum;
  68     private int min = Integer.MAX_VALUE;
  69     private int max = Integer.MIN_VALUE;
  70 
  71     /**
  72      * Constructs an empty instance with zero count, zero sum,
  73      * {@code Integer.MAX_VALUE} min, {@code Integer.MIN_VALUE} max and zero
  74      * average.
  75      */
  76     public IntSummaryStatistics() { }
  77 
  78     /**
  79      * Constructs a non-empty instance with the specified {@code count},
  80      * {@code min}, {@code max}, and {@code sum}.
  81      *
  82      * <p>If {@code count} is zero then the remaining arguments are ignored and


   1 /*
   2  * Copyright (c) 2012, 2019, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any


  42  *
  43  * <p>{@code IntSummaryStatistics} can be used as a
  44  * {@linkplain java.util.stream.Stream#collect(Collector) reduction}
  45  * target for a {@linkplain java.util.stream.Stream stream}. For example:
  46  *
  47  * <pre> {@code
  48  * IntSummaryStatistics stats = people.stream()
  49  *                                    .collect(Collectors.summarizingInt(Person::getDependents));
  50  *}</pre>
  51  *
  52  * This computes, in a single pass, the count of people, as well as the minimum,
  53  * maximum, sum, and average of their number of dependents.
  54  *
  55  * @implNote This implementation is not thread safe. However, it is safe to use
  56  * {@link java.util.stream.Collectors#summarizingInt(java.util.function.ToIntFunction)
  57  * Collectors.summarizingInt()} on a parallel stream, because the parallel
  58  * implementation of {@link java.util.stream.Stream#collect Stream.collect()}
  59  * provides the necessary partitioning, isolation, and merging of results for
  60  * safe and efficient parallel execution.
  61  *
  62  * <p>This implementation does not check for overflow of the count or the sum.
  63  * @since 1.8
  64  */
  65 public class IntSummaryStatistics implements IntConsumer {
  66     private long count;
  67     private long sum;
  68     private int min = Integer.MAX_VALUE;
  69     private int max = Integer.MIN_VALUE;
  70 
  71     /**
  72      * Constructs an empty instance with zero count, zero sum,
  73      * {@code Integer.MAX_VALUE} min, {@code Integer.MIN_VALUE} max and zero
  74      * average.
  75      */
  76     public IntSummaryStatistics() { }
  77 
  78     /**
  79      * Constructs a non-empty instance with the specified {@code count},
  80      * {@code min}, {@code max}, and {@code sum}.
  81      *
  82      * <p>If {@code count} is zero then the remaining arguments are ignored and


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