aoqi@0: /*
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aoqi@0:  * published by the Free Software Foundation.
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aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
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aoqi@0: 
aoqi@0: #ifndef SHARE_VM_UTILITIES_INTHISTO_HPP
aoqi@0: #define SHARE_VM_UTILITIES_INTHISTO_HPP
aoqi@0: 
aoqi@0: #include "memory/allocation.hpp"
aoqi@0: #include "utilities/growableArray.hpp"
aoqi@0: 
aoqi@0: // This class implements a simple histogram.
aoqi@0: 
aoqi@0: // A histogram summarizes a series of "measurements", each of which is
aoqi@0: // assumed (required in this implementation) to have an outcome that is a
aoqi@0: // non-negative integer.  The histogram efficiently maps measurement outcomes
aoqi@0: // to the number of measurements had that outcome.
aoqi@0: 
aoqi@0: // To print the results, invoke print() on your Histogram*.
aoqi@0: 
aoqi@0: // Note: there is already an existing "Histogram" class, in file
aoqi@0: // histogram.{hpp,cpp}, but to my mind that's not a histogram, it's a table
aoqi@0: // mapping strings to counts.  To be a histogram (IMHO) it needs to map
aoqi@0: // numbers (in fact, integers) to number of occurrences of that number.
aoqi@0: 
aoqi@0: // ysr: (i am not sure i agree with the above note.) i suspect we want to have a
aoqi@0: // histogram template that will map an arbitrary type (with a defined order
aoqi@0: // relation) to a count.
aoqi@0: 
aoqi@0: 
aoqi@0: class IntHistogram : public CHeapObj<mtInternal> {
aoqi@0:  protected:
aoqi@0:   int _max;
aoqi@0:   int _tot;
aoqi@0:   GrowableArray<int>* _elements;
aoqi@0: 
aoqi@0: public:
aoqi@0:   // Create a new, empty table.  "est" is an estimate of the maximum outcome
aoqi@0:   // that will be added, and "max" is an outcome such that all outcomes at
aoqi@0:   // least that large will be bundled with it.
aoqi@0:   IntHistogram(int est, int max);
aoqi@0:   // Add a measurement with the given outcome to the sequence.
aoqi@0:   void add_entry(int outcome);
aoqi@0:   // Return the number of entries recorded so far with the given outcome.
aoqi@0:   int  entries_for_outcome(int outcome);
aoqi@0:   // Return the total number of entries recorded so far.
aoqi@0:   int  total_entries() { return _tot; }
aoqi@0:   // Return the number of entries recorded so far with the given outcome as
aoqi@0:   // a fraction of the total number recorded so far.
aoqi@0:   double fraction_for_outcome(int outcome) {
aoqi@0:     return
aoqi@0:       (double)entries_for_outcome(outcome)/
aoqi@0:       (double)total_entries();
aoqi@0:   }
aoqi@0:   // Print the histogram on the given output stream.
aoqi@0:   void print_on(outputStream* st) const;
aoqi@0: };
aoqi@0: 
aoqi@0: #endif // SHARE_VM_UTILITIES_INTHISTO_HPP