mirror of
https://github.com/ceph/ceph
synced 2025-01-09 04:30:26 +00:00
9213a23f14
git-svn-id: https://ceph.svn.sf.net/svnroot/ceph@1138 29311d96-e01e-0410-9327-a35deaab8ce9
75 lines
1.4 KiB
C++
75 lines
1.4 KiB
C++
// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
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/*
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* Ceph - scalable distributed file system
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*
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* Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
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*
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* This is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License version 2.1, as published by the Free Software
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* Foundation. See file COPYING.
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*
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*/
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#ifndef __DISTRIBUTION_H
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#define __DISTRIBUTION_H
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#include <cassert>
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#include <vector>
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using namespace std;
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class Distribution {
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vector<float> p;
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vector<int> v;
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public:
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//Distribution() {
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//}
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unsigned get_width() {
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return p.size();
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}
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void clear() {
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p.clear();
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v.clear();
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}
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void add(int val, float pr) {
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p.push_back(pr);
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v.push_back(val);
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}
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void random() {
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float sum = 0.0;
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for (unsigned i=0; i<p.size(); i++) {
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p[i] = (float)(rand() % 10000);
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sum += p[i];
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}
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for (unsigned i=0; i<p.size(); i++)
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p[i] /= sum;
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}
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int sample() {
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float s = (float)(rand() % 10000) / 10000.0;
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for (unsigned i=0; i<p.size(); i++) {
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if (s < p[i]) return v[i];
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s -= p[i];
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}
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assert(0);
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return v[p.size() - 1]; // hmm. :/
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}
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float normalize() {
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float s = 0.0;
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for (unsigned i=0; i<p.size(); i++)
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s += p[i];
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for (unsigned i=0; i<p.size(); i++)
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p[i] /= s;
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return s;
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}
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};
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#endif
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