intHisto.hpp revision 3718:b9a9ed0f8eeb
1193323Sed/* 2193323Sed * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. 3193323Sed * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4193323Sed * 5193323Sed * This code is free software; you can redistribute it and/or modify it 6193323Sed * under the terms of the GNU General Public License version 2 only, as 7193323Sed * published by the Free Software Foundation. 8193323Sed * 9193323Sed * This code is distributed in the hope that it will be useful, but WITHOUT 10193323Sed * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11193323Sed * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12193323Sed * version 2 for more details (a copy is included in the LICENSE file that 13193323Sed * accompanied this code). 14193323Sed * 15193323Sed * You should have received a copy of the GNU General Public License version 16193323Sed * 2 along with this work; if not, write to the Free Software Foundation, 17193323Sed * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18234353Sdim * 19193323Sed * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20234353Sdim * or visit www.oracle.com if you need additional information or have any 21193323Sed * questions. 22198090Srdivacky * 23193323Sed */ 24193323Sed 25193323Sed#ifndef SHARE_VM_UTILITIES_INTHISTO_HPP 26249423Sdim#define SHARE_VM_UTILITIES_INTHISTO_HPP 27249423Sdim 28193323Sed#include "memory/allocation.hpp" 29193323Sed#include "utilities/growableArray.hpp" 30193323Sed 31193323Sed// This class implements a simple histogram. 32193323Sed 33193323Sed// A histogram summarizes a series of "measurements", each of which is 34193323Sed// assumed (required in this implementation) to have an outcome that is a 35193323Sed// non-negative integer. The histogram efficiently maps measurement outcomes 36193323Sed// to the number of measurements had that outcome. 37193323Sed 38193323Sed// To print the results, invoke print() on your Histogram*. 39193323Sed 40198090Srdivacky// Note: there is already an existing "Histogram" class, in file 41193323Sed// histogram.{hpp,cpp}, but to my mind that's not a histogram, it's a table 42193323Sed// mapping strings to counts. To be a histogram (IMHO) it needs to map 43193323Sed// numbers (in fact, integers) to number of occurrences of that number. 44193323Sed 45193323Sed// ysr: (i am not sure i agree with the above note.) i suspect we want to have a 46193323Sed// histogram template that will map an arbitrary type (with a defined order 47193323Sed// relation) to a count. 48198090Srdivacky 49198090Srdivacky 50198090Srdivackyclass IntHistogram : public CHeapObj<mtInternal> { 51198090Srdivacky protected: 52226633Sdim int _max; 53198090Srdivacky int _tot; 54198090Srdivacky GrowableArray<int>* _elements; 55198090Srdivacky 56198090Srdivackypublic: 57198090Srdivacky // Create a new, empty table. "est" is an estimate of the maximum outcome 58226633Sdim // that will be added, and "max" is an outcome such that all outcomes at 59198090Srdivacky // least that large will be bundled with it. 60198090Srdivacky IntHistogram(int est, int max); 61198090Srdivacky // Add a measurement with the given outcome to the sequence. 62226633Sdim void add_entry(int outcome); 63198090Srdivacky // Return the number of entries recorded so far with the given outcome. 64226633Sdim int entries_for_outcome(int outcome); 65226633Sdim // Return the total number of entries recorded so far. 66198090Srdivacky int total_entries() { return _tot; } 67198090Srdivacky // Return the number of entries recorded so far with the given outcome as 68198090Srdivacky // a fraction of the total number recorded so far. 69198090Srdivacky double fraction_for_outcome(int outcome) { 70198090Srdivacky return 71198090Srdivacky (double)entries_for_outcome(outcome)/ 72198090Srdivacky (double)total_entries(); 73198090Srdivacky } 74198090Srdivacky // Print the histogram on the given output stream. 75198090Srdivacky void print_on(outputStream* st) const; 76193323Sed}; 77193323Sed 78193323Sed#endif // SHARE_VM_UTILITIES_INTHISTO_HPP 79198090Srdivacky