1// Copyright (c) 2009-2010 Satoshi Nakamoto
2// Copyright (c) 2009-present The Bitcoin Core developers
3// Distributed under the MIT software license, see the accompanying
4// file COPYING or http://www.opensource.org/licenses/mit-license.php.
5
6#ifndef BITCOIN_UTIL_TIME_H
7#define BITCOIN_UTIL_TIME_H
8
9// The `util/time.h` header is designed to be a drop-in replacement for `chrono`.
10#include <chrono> // IWYU pragma: export
11#include <cstdint>
12#include <ctime>
13#include <optional>
14#include <string>
15#include <string_view>
16
17#ifdef WIN32
18#include <winsock2.h>
19#else
20#include <sys/time.h>
21#endif
22
23using namespace std::chrono_literals;
24
25/// Version of the system clock that is mockable in the context of tests (via
26/// FakeNodeClock or ::SetMockTime), otherwise the system clock.
27struct NodeClock : public std::chrono::system_clock {
28    using time_point = std::chrono::time_point<NodeClock>;
29    /** Return current system time or mocked time, if set */
30    static time_point now() noexcept;
31    static std::time_t to_time_t(const time_point&) = delete; // unused
32    static time_point from_time_t(std::time_t) = delete;      // unused
33    static constexpr time_point epoch{};
34};
35using NodeSeconds = std::chrono::time_point<NodeClock, std::chrono::seconds>;
36
37using SteadyClock = std::chrono::steady_clock;
38using SteadySeconds = std::chrono::time_point<std::chrono::steady_clock, std::chrono::seconds>;
39using SteadyMilliseconds = std::chrono::time_point<std::chrono::steady_clock, std::chrono::milliseconds>;
40using SteadyMicroseconds = std::chrono::time_point<std::chrono::steady_clock, std::chrono::microseconds>;
41
42using SystemClock = std::chrono::system_clock;
43
44/// Version of SteadyClock that is mockable in the context of tests (via
45/// FakeSteadyClock, or Self::SetMockTime), otherwise the system steady
46/// clock.
47struct MockableSteadyClock : public std::chrono::steady_clock {
48    using time_point = std::chrono::time_point<MockableSteadyClock>;
49
50    using mock_time_point = std::chrono::time_point<MockableSteadyClock, std::chrono::milliseconds>;
51    static constexpr mock_time_point::duration INITIAL_MOCK_TIME{1};
52
53    /** Return current system time or mocked time, if set */
54    static time_point now() noexcept;
55    static std::time_t to_time_t(const time_point&) = delete; // unused
56    static time_point from_time_t(std::time_t) = delete;      // unused
57
58    /** Set mock time for testing.
59     * When mocking the steady clock, start at INITIAL_MOCK_TIME and add durations to elapse time as necessary
60     * for testing.
61     * To stop mocking, call ClearMockTime().
62     */
63    static void SetMockTime(mock_time_point::duration mock_time_in);
64
65    /** Clear mock time, go back to system steady clock. */
66    static void ClearMockTime();
67};
68
69void UninterruptibleSleep(const std::chrono::microseconds& n);
70
71/**
72 * Helper to count the seconds of a duration/time_point.
73 *
74 * All durations/time_points should be using std::chrono and calling this should generally
75 * be avoided in code. Though, it is still preferred to an inline t.count() to
76 * protect against a reliance on the exact type of t.
77 *
78 * This helper is used to convert durations/time_points before passing them over an
79 * interface that doesn't support std::chrono (e.g. RPC, debug log, or the GUI)
80 */
81template <typename Dur1, typename Dur2>
82constexpr auto Ticks(Dur2 d)
83{
84    return std::chrono::duration_cast<Dur1>(d).count();
85}
86
87template <typename Duration>
88constexpr int64_t TicksSeconds(Duration d)
89{
90    return int64_t{Ticks<std::chrono::seconds>(d)};
91}
92template <typename Duration, typename Timepoint>
93constexpr auto TicksSinceEpoch(Timepoint t)
94{
95    return Ticks<Duration>(t.time_since_epoch());
96}
97constexpr int64_t count_seconds(std::chrono::seconds t) { return t.count(); }
98constexpr int64_t count_milliseconds(std::chrono::milliseconds t) { return t.count(); }
99constexpr int64_t count_microseconds(std::chrono::microseconds t) { return t.count(); }
100
101using HoursDouble = std::chrono::duration<double, std::chrono::hours::period>;
102using SecondsDouble = std::chrono::duration<double, std::chrono::seconds::period>;
103using MillisecondsDouble = std::chrono::duration<double, std::chrono::milliseconds::period>;
104
105/**
106 * DEPRECATED
107 * Use either ClockType::now() or Now<TimePointType>() if a cast is needed.
108 * ClockType is
109 * - SteadyClock/std::chrono::steady_clock for steady time
110 * - SystemClock/std::chrono::system_clock for system time
111 * - NodeClock                             for mockable system time
112 */
113int64_t GetTime();
114
115/** For testing. Set e.g. with the setmocktime rpc, or -mocktime argument */
116void SetMockTime(std::chrono::seconds mock_time_in);
117void SetMockTime(std::chrono::time_point<NodeClock, std::chrono::seconds> mock);
118
119/** For testing */
120std::chrono::seconds GetMockTime();
121
122/**
123 * Return the current time point cast to the given precision. Only use this
124 * when an exact precision is needed, otherwise use T::clock::now() directly.
125 */
126template <typename T>
127T Now()
128{
129    return std::chrono::time_point_cast<typename T::duration>(T::clock::now());
130}
131/** DEPRECATED, see GetTime */
132template <typename T>
133T GetTime()
134{
135    return Now<std::chrono::time_point<NodeClock, T>>().time_since_epoch();
136}
137
138/**
139 * ISO 8601 formatting is preferred. Use the FormatISO8601{DateTime,Date}
140 * helper functions if possible.
141 */
142std::string FormatISO8601DateTime(int64_t nTime);
143std::string FormatISO8601Date(int64_t nTime);
144std::optional<int64_t> ParseISO8601DateTime(std::string_view str);
145
146/**
147 * RFC1123 formatting https://www.rfc-editor.org/rfc/rfc1123#section-5.2.14
148 * Used in HTTP/1.1 responses
149 */
150std::string FormatRFC1123DateTime(int64_t nTime);
151
152/**
153 * Convert milliseconds to a struct timeval for e.g. select.
154 */
155struct timeval MillisToTimeval(int64_t nTimeout);
156
157/**
158 * Convert milliseconds to a struct timeval for e.g. select.
159 */
160struct timeval MillisToTimeval(std::chrono::milliseconds ms);
161
162#endif // BITCOIN_UTIL_TIME_H
163