Electroneum
output_selection.cpp
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29 
30 // FIXME: move this into a full wallet2 unit test suite, if possible
31 
32 #include "gtest/gtest.h"
33 
34 #include "wallet/wallet2.h"
35 #include <string>
36 
37 static tools::wallet2::transfer_container make_transfers_container(size_t N)
38 {
40  for (size_t n = 0; n < N; ++n)
41  {
42  transfers.push_back(AUTO_VAL_INIT(tools::wallet2::transfer_details()));
43  tools::wallet2::transfer_details &td = transfers.back();
44  td.m_block_height = 1000;
45  td.m_spent = false;
46  td.m_txid = crypto::null_hash;
47  td.m_txid.data[0] = n & 0xff;
48  td.m_txid.data[1] = (n >> 8) & 0xff;
49  td.m_txid.data[2] = (n >> 16) & 0xff;
50  td.m_txid.data[3] = (n >> 24) & 0xff;
51  }
52  return transfers;
53 }
54 
55 #define SELECT(idx) \
56  do { \
57  auto i = std::find(unused_indices.begin(), unused_indices.end(), idx); \
58  ASSERT_TRUE(i != unused_indices.end()); \
59  unused_indices.erase(i); \
60  selected.push_back(idx); \
61  } while(0)
62 
63 #define PICK(expected) \
64  do { \
65  size_t idx = w.pop_best_value_from(transfers, unused_indices, selected); \
66  ASSERT_EQ(expected, idx); \
67  selected.push_back(idx); \
68  } while(0)
69 
70 TEST(select_outputs, one_out_of_N)
71 {
73 
74  // check that if there are N-1 outputs of the same height, one of them
75  // already selected, the next one selected is the one that's from a
76  // different height
77  tools::wallet2::transfer_container transfers = make_transfers_container(10);
78  transfers[6].m_block_height = 700;
79  std::vector<size_t> unused_indices({0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
80  std::vector<size_t> selected;
81  SELECT(2);
82  PICK(6);
83 }
84 
85 TEST(select_outputs, order)
86 {
88 
89  // check that most unrelated heights are picked in order
90  tools::wallet2::transfer_container transfers = make_transfers_container(5);
91  transfers[0].m_block_height = 700;
92  transfers[1].m_block_height = 700;
93  transfers[2].m_block_height = 704;
94  transfers[3].m_block_height = 716;
95  transfers[4].m_block_height = 701;
96  std::vector<size_t> unused_indices({0, 1, 2, 3, 4});
97  std::vector<size_t> selected;
98  SELECT(0);
99  PICK(3); // first the one that's far away
100  PICK(2); // then the one that's close
101  PICK(4); // then the one that's adjacent
102  PICK(1); // then the one that's on the same height
103 }
104 
105 #define MKOFFSETS(N, n) \
106  offsets.resize(N); \
107  size_t n_outs = 0; \
108  for (auto &offset: offsets) \
109  { \
110  offset = n_outs += (n); \
111  }
112 
113 TEST(select_outputs, gamma)
114 {
115  std::vector<uint64_t> offsets;
116 
117  MKOFFSETS(300000, 1);
118  tools::gamma_picker picker(offsets);
119  std::vector<double> ages(100000);
120  double age_scale = 120. * (offsets.size() / (double)n_outs);
121  for (size_t i = 0; i < ages.size(); )
122  {
123  uint64_t o = picker.pick();
124  if (o >= n_outs)
125  continue;
126  ages[i] = (n_outs - 1 - o) * age_scale;
127  ASSERT_GE(ages[i], 0);
128  ASSERT_LE(ages[i], offsets.size() * 120);
129  ++i;
130  }
131  double median = epee::misc_utils::median(ages);
132  MDEBUG("median age: " << median / 86400. << " days");
133  ASSERT_GE(median, 1.3 * 86400);
134  ASSERT_LE(median, 1.4 * 86400);
135 }
136 
137 TEST(select_outputs, density)
138 {
139  static const size_t NPICKS = 1000000;
140  std::vector<uint64_t> offsets;
141 
142  MKOFFSETS(300000, 1 + (rand() & 0x1f));
143  tools::gamma_picker picker(offsets);
144 
145  std::vector<int> picks(/*n_outs*/offsets.size(), 0);
146  for (int i = 0; i < NPICKS; )
147  {
148  uint64_t o = picker.pick();
149  if (o >= n_outs)
150  continue;
151  auto it = std::lower_bound(offsets.begin(), offsets.end(), o);
152  auto idx = std::distance(offsets.begin(), it);
153  ASSERT_LT(idx, picks.size());
154  ++picks[idx];
155  ++i;
156  }
157 
158  for (int d = 1; d < 0x20; ++d)
159  {
160  // count the number of times an output in a block of d outputs was selected
161  // count how many outputs are in a block of d outputs
162  size_t count_selected = 0, count_chain = 0;
163  for (size_t i = 0; i < offsets.size(); ++i)
164  {
165  size_t n_outputs = offsets[i] - (i == 0 ? 0 : offsets[i - 1]);
166  if (n_outputs == d)
167  {
168  count_selected += picks[i];
169  count_chain += d;
170  }
171  }
172  float selected_ratio = count_selected / (float)NPICKS;
173  float chain_ratio = count_chain / (float)n_outs;
174  MDEBUG(count_selected << "/" << NPICKS << " outputs selected in blocks of density " << d << ", " << 100.0f * selected_ratio << "%");
175  MDEBUG(count_chain << "/" << offsets.size() << " outputs in blocks of density " << d << ", " << 100.0f * chain_ratio << "%");
176  ASSERT_LT(fabsf(selected_ratio - chain_ratio), 0.025f);
177  }
178 }
179 
180 TEST(select_outputs, same_distribution)
181 {
182  static const size_t NPICKS = 1000000;
183  std::vector<uint64_t> offsets;
184 
185  MKOFFSETS(300000, 1 + (rand() & 0x1f));
186  tools::gamma_picker picker(offsets);
187 
188  std::vector<int> chain_picks(offsets.size(), 0);
189  std::vector<int> output_picks(n_outs, 0);
190  for (int i = 0; i < NPICKS; )
191  {
192  uint64_t o = picker.pick();
193  if (o >= n_outs)
194  continue;
195  auto it = std::lower_bound(offsets.begin(), offsets.end(), o);
196  auto idx = std::distance(offsets.begin(), it);
197  ASSERT_LT(idx, chain_picks.size());
198  ++chain_picks[idx];
199  ++output_picks[o];
200  ++i;
201  }
202 
203  // scale them both to 0-100
204  std::vector<int> chain_norm(100, 0), output_norm(100, 0);
205  for (size_t i = 0; i < output_picks.size(); ++i)
206  output_norm[i * 100 / output_picks.size()] += output_picks[i];
207  for (size_t i = 0; i < chain_picks.size(); ++i)
208  chain_norm[i * 100 / chain_picks.size()] += chain_picks[i];
209 
210  double max_dev = 0.0, avg_dev = 0.0;
211  for (size_t i = 0; i < 100; ++i)
212  {
213  const double diff = (double)output_norm[i] - (double)chain_norm[i];
214  double dev = fabs(2.0 * diff / (output_norm[i] + chain_norm[i]));
215  ASSERT_LT(dev, 0.1);
216  avg_dev += dev;
217  }
218  avg_dev /= 100;
219  MDEBUG("avg_dev: " << avg_dev);
220  ASSERT_LT(avg_dev, 0.015);
221 }
TEST(select_outputs, one_out_of_N)
#define ASSERT_GE(val1, val2)
Definition: gtest.h:1972
#define MKOFFSETS(N, n)
#define MDEBUG(x)
Definition: misc_log_ex.h:76
void rand(size_t N, uint8_t *bytes)
Definition: crypto.h:209
std::vector< transfer_details > transfer_container
Definition: wallet2.h:449
unsigned __int64 uint64_t
Definition: stdint.h:136
#define PICK(expected)
#define ASSERT_LT(val1, val2)
Definition: gtest.h:1968
type_vec_type median(std::vector< type_vec_type > &v)
#define SELECT(idx)
#define AUTO_VAL_INIT(v)
Definition: misc_language.h:53
#define ASSERT_LE(val1, val2)
Definition: gtest.h:1964