1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/utilities/intHisto.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,78 @@
1.4 +/*
1.5 + * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_UTILITIES_INTHISTO_HPP
1.29 +#define SHARE_VM_UTILITIES_INTHISTO_HPP
1.30 +
1.31 +#include "memory/allocation.hpp"
1.32 +#include "utilities/growableArray.hpp"
1.33 +
1.34 +// This class implements a simple histogram.
1.35 +
1.36 +// A histogram summarizes a series of "measurements", each of which is
1.37 +// assumed (required in this implementation) to have an outcome that is a
1.38 +// non-negative integer. The histogram efficiently maps measurement outcomes
1.39 +// to the number of measurements had that outcome.
1.40 +
1.41 +// To print the results, invoke print() on your Histogram*.
1.42 +
1.43 +// Note: there is already an existing "Histogram" class, in file
1.44 +// histogram.{hpp,cpp}, but to my mind that's not a histogram, it's a table
1.45 +// mapping strings to counts. To be a histogram (IMHO) it needs to map
1.46 +// numbers (in fact, integers) to number of occurrences of that number.
1.47 +
1.48 +// ysr: (i am not sure i agree with the above note.) i suspect we want to have a
1.49 +// histogram template that will map an arbitrary type (with a defined order
1.50 +// relation) to a count.
1.51 +
1.52 +
1.53 +class IntHistogram : public CHeapObj<mtInternal> {
1.54 + protected:
1.55 + int _max;
1.56 + int _tot;
1.57 + GrowableArray<int>* _elements;
1.58 +
1.59 +public:
1.60 + // Create a new, empty table. "est" is an estimate of the maximum outcome
1.61 + // that will be added, and "max" is an outcome such that all outcomes at
1.62 + // least that large will be bundled with it.
1.63 + IntHistogram(int est, int max);
1.64 + // Add a measurement with the given outcome to the sequence.
1.65 + void add_entry(int outcome);
1.66 + // Return the number of entries recorded so far with the given outcome.
1.67 + int entries_for_outcome(int outcome);
1.68 + // Return the total number of entries recorded so far.
1.69 + int total_entries() { return _tot; }
1.70 + // Return the number of entries recorded so far with the given outcome as
1.71 + // a fraction of the total number recorded so far.
1.72 + double fraction_for_outcome(int outcome) {
1.73 + return
1.74 + (double)entries_for_outcome(outcome)/
1.75 + (double)total_entries();
1.76 + }
1.77 + // Print the histogram on the given output stream.
1.78 + void print_on(outputStream* st) const;
1.79 +};
1.80 +
1.81 +#endif // SHARE_VM_UTILITIES_INTHISTO_HPP
