/*+
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 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.+
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.+
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 *+
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 * This code is free software; you can redistribute it and/or modify it+
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 * under the terms of the GNU General Public License version 2 only, as+
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 * published by the Free Software Foundation.+
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 *+
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 * This code is distributed in the hope that it will be useful, but WITHOUT+
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or+
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License+
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 * version 2 for more details (a copy is included in the LICENSE file that+
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 * accompanied this code).+
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 *+
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 * You should have received a copy of the GNU General Public License version+
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 * 2 along with this work; if not, write to the Free Software Foundation,+
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.+
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 *+
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA+
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 * or visit www.oracle.com if you need additional information or have any+
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 * questions.+
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 *+
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 */+
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+
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#ifndef SHARE_VM_UTILITIES_INTHISTO_HPP+
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#define SHARE_VM_UTILITIES_INTHISTO_HPP+
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+
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#include "memory/allocation.hpp"+
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#include "utilities/growableArray.hpp"+
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+
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// This class implements a simple histogram.+
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+
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// A histogram summarizes a series of "measurements", each of which is+
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// assumed (required in this implementation) to have an outcome that is a+
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// non-negative integer.  The histogram efficiently maps measurement outcomes+
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// to the number of measurements had that outcome.+
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+
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// To print the results, invoke print() on your Histogram*.+
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+
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// Note: there is already an existing "Histogram" class, in file+
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// histogram.{hpp,cpp}, but to my mind that's not a histogram, it's a table+
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// mapping strings to counts.  To be a histogram (IMHO) it needs to map+
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// numbers (in fact, integers) to number of occurrences of that number.+
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+
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// ysr: (i am not sure i agree with the above note.) i suspect we want to have a+
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// histogram template that will map an arbitrary type (with a defined order+
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// relation) to a count.+
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+
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+
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class IntHistogram : public CHeapObj<mtInternal> {+
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 protected:+
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  int _max;+
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  int _tot;+
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  GrowableArray<int>* _elements;+
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+
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public:+
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  // Create a new, empty table.  "est" is an estimate of the maximum outcome+
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  // that will be added, and "max" is an outcome such that all outcomes at+
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  // least that large will be bundled with it.+
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  IntHistogram(int est, int max);+
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  // Add a measurement with the given outcome to the sequence.+
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  void add_entry(int outcome);+
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  // Return the number of entries recorded so far with the given outcome.+
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  int  entries_for_outcome(int outcome);+
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  // Return the total number of entries recorded so far.+
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  int  total_entries() { return _tot; }+
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  // Return the number of entries recorded so far with the given outcome as+
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  // a fraction of the total number recorded so far.+
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  double fraction_for_outcome(int outcome) {+
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    return+
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      (double)entries_for_outcome(outcome)/+
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      (double)total_entries();+
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  }+
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  // Print the histogram on the given output stream.+
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  void print_on(outputStream* st) const;+
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};+
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+
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#endif // SHARE_VM_UTILITIES_INTHISTO_HPP+
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