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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#ifndef CEPH_DISTRIBUTION_H
#define CEPH_DISTRIBUTION_H
#include <vector>
class Distribution {
std::vector<float> p;
std::vector<int> v;
public:
//Distribution() {
//}
unsigned get_width() {
return p.size();
}
void clear() {
p.clear();
v.clear();
}
void add(int val, float pr) {
p.push_back(pr);
v.push_back(val);
}
void random() {
float sum = 0.0;
for (unsigned i=0; i<p.size(); i++) {
p[i] = (float)(rand() % 10000);
sum += p[i];
}
for (unsigned i=0; i<p.size(); i++)
p[i] /= sum;
}
int sample() {
float s = (float)(rand() % 10000) / 10000.0;
for (unsigned i=0; i<p.size(); i++) {
if (s < p[i]) return v[i];
s -= p[i];
}
ceph_abort();
return v[p.size() - 1]; // hmm. :/
}
float normalize() {
float s = 0.0;
for (unsigned i=0; i<p.size(); i++)
s += p[i];
for (unsigned i=0; i<p.size(); i++)
p[i] /= s;
return s;
}
};
#endif
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