ceph/src/test/bench/distribution.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2
   3 #ifndef DISTIRITBIONHPP
   4 #define DISTIRITBIONHPP
   5
   6 #include <map>
   7 #include <set>
   8 #include <utility>
   9 #include <vector>
  10 #include <boost/random/mersenne_twister.hpp>
  11 #include <boost/random/uniform_int.hpp>
  12 #include <boost/random/uniform_real.hpp>
  13 #include <boost/scoped_ptr.hpp>
  14 #include <boost/tuple/tuple.hpp>
  15
  16 typedef boost::mt11213b rngen_t;
  17
  18 template <typename T>
  19 class Distribution {
  20 public:
  21   virtual T operator()() = 0;
  22   virtual ~Distribution() {}
  23 };
  24
  25 template <typename T, typename U, typename V, typename W>
  26 class FourTupleDist : public Distribution<boost::tuple<T, U, V, W> > {
  27   boost::scoped_ptr<Distribution<T> > t;
  28   boost::scoped_ptr<Distribution<U> > u;
  29   boost::scoped_ptr<Distribution<V> > v;
  30   boost::scoped_ptr<Distribution<W> > w;
  31 public:
  32   FourTupleDist(
  33     Distribution<T> *t,
  34     Distribution<U> *u,
  35     Distribution<V> *v,
  36     Distribution<W> *w)
  37     : t(t), u(u), v(v), w(w) {}
  38   boost::tuple<T, U, V, W> operator()() override {
  39     return boost::make_tuple((*t)(), (*u)(), (*v)(), (*w)());
  40   }
  41 };
  42
  43 template <typename T>
  44 class RandomDist : public Distribution<T> {
  45   rngen_t rng;
  46   std::map<uint64_t, T> contents;
  47 public:
  48   RandomDist(const rngen_t &rng, std::set<T> &initial) : rng(rng) {
  49     uint64_t count = 0;
  50     for (typename std::set<T>::iterator i = initial.begin();
  51          i != initial.end();
  52          ++i, ++count) {
  53       contents.insert(std::make_pair(count, *i));
  54     }
  55   }
  56   T operator()() override {
  57     assert(contents.size());
  58     boost::uniform_int<> value(0, contents.size() - 1);
  59     return contents.find(value(rng))->second;
  60   }
  61 };
  62
  63 template <typename T>
  64 class WeightedDist : public Distribution<T> {
  65   rngen_t rng;
  66   double total;
  67   std::map<double, T> contents;
  68 public:
  69   WeightedDist(const rngen_t &rng, const std::set<std::pair<double, T> > &initial)
  70     : rng(rng), total(0) {
  71     for (typename std::set<std::pair<double, T> >::const_iterator i =
  72            initial.begin();
  73          i != initial.end();
  74          ++i) {
  75       total += i->first;
  76       contents.insert(std::make_pair(total, i->second));
  77     }
  78   }
  79   T operator()() override {
  80     return contents.lower_bound(
  81       boost::uniform_real<>(0, total)(rng))->second;
  82   }
  83 };
  84
  85 template <typename T, typename U>
  86 class SequentialDist : public Distribution<T> {
  87   rngen_t rng;
  88   std::vector<T> contents;
  89   typename std::vector<T>::iterator cur;
  90 public:
  91   SequentialDist(rngen_t rng, U &initial) : rng(rng) {
  92     contents.insert(initial.begin(), initial.end());
  93     cur = contents.begin();
  94   }
  95   virtual T operator()() {
  96     assert(contents.size());
  97     if (cur == contents.end())
  98       cur = contents.begin();
  99     return *(cur++);
 100   }
 101 };
 102
 103 class UniformRandom : public Distribution<uint64_t> {
 104   rngen_t rng;
 105   uint64_t min;
 106   uint64_t max;
 107 public:
 108   UniformRandom(const rngen_t &rng, uint64_t min, uint64_t max) :
 109     rng(rng), min(min), max(max) {}
 110   uint64_t operator()() override {
 111     return boost::uniform_int<uint64_t>(min, max)(rng);
 112   }
 113 };
 114
 115 class Align : public Distribution<uint64_t> {
 116   boost::scoped_ptr<Distribution<uint64_t> > dist;
 117   uint64_t align;
 118 public:
 119   Align(Distribution<uint64_t> *dist, uint64_t align) :
 120     dist(dist), align(align) {}
 121   uint64_t operator()() override {
 122     uint64_t ret = (*dist)();
 123     return ret - (ret % align);
 124   }
 125 };
 126
 127 class Uniform : public Distribution<uint64_t> {
 128   uint64_t val;
 129 public:
 130   explicit Uniform(uint64_t val) : val(val) {}
 131   uint64_t operator()() override {
 132     return val;
 133   }
 134 };
 135
 136 #endif