Electroneum
rpc_handler.cpp
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1 
2 #include <algorithm>
3 #include <boost/thread/locks.hpp>
4 #include <boost/thread/mutex.hpp>
5 
7 
8 namespace cryptonote
9 {
10 namespace rpc
11 {
12  namespace
13  {
14  output_distribution_data
15  process_distribution(bool cumulative, std::uint64_t start_height, std::vector<std::uint64_t> distribution, std::uint64_t base)
16  {
17  if (!cumulative && !distribution.empty())
18  {
19  for (std::size_t n = distribution.size() - 1; 0 < n; --n)
20  distribution[n] -= distribution[n - 1];
21  distribution[0] -= base;
22  }
23 
24  return {std::move(distribution), start_height, base};
25  }
26  }
27 
28  boost::optional<output_distribution_data>
29  RpcHandler::get_output_distribution(const std::function<bool(uint64_t, uint64_t, uint64_t, uint64_t&, std::vector<uint64_t>&, uint64_t&)> &f, uint64_t amount, uint64_t from_height, uint64_t to_height, const std::function<crypto::hash(uint64_t)> &get_hash, bool cumulative, uint64_t blockchain_height)
30  {
31  static struct D
32  {
33  boost::mutex mutex;
34  std::vector<std::uint64_t> cached_distribution;
35  std::uint64_t cached_from, cached_to, cached_start_height, cached_base;
36  crypto::hash cached_m10_hash;
37  crypto::hash cached_top_hash;
38  bool cached;
39  D(): cached_from(0), cached_to(0), cached_start_height(0), cached_base(0), cached_m10_hash(crypto::null_hash), cached_top_hash(crypto::null_hash), cached(false) {}
40  } d;
41  const boost::unique_lock<boost::mutex> lock(d.mutex);
42 
43  crypto::hash top_hash = crypto::null_hash;
44  if (d.cached_to < blockchain_height)
45  top_hash = get_hash(d.cached_to);
46  if (d.cached && amount == 0 && d.cached_from == from_height && d.cached_to == to_height && d.cached_top_hash == top_hash)
47  return process_distribution(cumulative, d.cached_start_height, d.cached_distribution, d.cached_base);
48 
49  std::vector<std::uint64_t> distribution;
50  std::uint64_t start_height, base;
51 
52  // see if we can extend the cache - a common case
53  bool can_extend = d.cached && amount == 0 && d.cached_from == from_height && to_height > d.cached_to && top_hash == d.cached_top_hash;
54  if (!can_extend)
55  {
56  // we kept track of the hash 10 blocks below, if it exists, so if it matches,
57  // we can still pop the last 10 cached slots and try again
58  if (d.cached && amount == 0 && d.cached_from == from_height && d.cached_to - d.cached_from >= 10 && to_height > d.cached_to - 10)
59  {
60  crypto::hash hash10 = get_hash(d.cached_to - 10);
61  if (hash10 == d.cached_m10_hash)
62  {
63  d.cached_to -= 10;
64  d.cached_top_hash = hash10;
65  d.cached_m10_hash = crypto::null_hash;
66  d.cached_distribution.resize(d.cached_distribution.size() - 10);
67  can_extend = true;
68  }
69  }
70  }
71  if (can_extend)
72  {
73  std::vector<std::uint64_t> new_distribution;
74  if (!f(amount, d.cached_to + 1, to_height, start_height, new_distribution, base))
75  return boost::none;
76  distribution = d.cached_distribution;
77  distribution.reserve(distribution.size() + new_distribution.size());
78  for (const auto &e: new_distribution)
79  distribution.push_back(e);
80  start_height = d.cached_start_height;
81  base = d.cached_base;
82  }
83  else
84  {
85  if (!f(amount, from_height, to_height, start_height, distribution, base))
86  return boost::none;
87  }
88 
89  if (to_height > 0 && to_height >= from_height)
90  {
91  const std::uint64_t offset = std::max(from_height, start_height);
92  if (offset <= to_height && to_height - offset + 1 < distribution.size())
93  distribution.resize(to_height - offset + 1);
94  }
95 
96  if (amount == 0)
97  {
98  d.cached_from = from_height;
99  d.cached_to = to_height;
100  d.cached_top_hash = get_hash(d.cached_to);
101  d.cached_m10_hash = d.cached_to >= 10 ? get_hash(d.cached_to - 10) : crypto::null_hash;
102  d.cached_distribution = distribution;
103  d.cached_start_height = start_height;
104  d.cached_base = base;
105  d.cached = true;
106  }
107 
108  return process_distribution(cumulative, start_height, std::move(distribution), base);
109  }
110 } // rpc
111 } // cryptonote
Holds cryptonote related classes and helpers.
Definition: ban.cpp:40
unsigned __int64 uint64_t
Definition: stdint.h:136
const T & move(const T &t)
Definition: gtest-port.h:1317
POD_CLASS hash
Definition: hash.h:50
static boost::optional< output_distribution_data > get_output_distribution(const std::function< bool(uint64_t, uint64_t, uint64_t, uint64_t &, std::vector< uint64_t > &, uint64_t &)> &f, uint64_t amount, uint64_t from_height, uint64_t to_height, const std::function< crypto::hash(uint64_t)> &get_hash, bool cumulative, uint64_t blockchain_height)
Definition: rpc_handler.cpp:29