1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

use std::fmt;
use std::marker::PhantomData;

#[cfg(feature = "chrono")]
use chrono;

use serde::de::{Error, Visitor};
use serde::Deserializer;

/// Types that can be deserialized via `#[serde(with = "serde_nanos")]`.
pub trait Deserialize<'de>: Sized {
    #[allow(missing_docs)]
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>;
}

impl<'de> Deserialize<'de> for std::time::Duration {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        serde::Deserialize::deserialize(deserializer)
            .map(|nanos| std::time::Duration::from_nanos(nanos))
    }
}

impl<'de> Deserialize<'de> for Option<std::time::Duration> {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        struct OptionVisitor<T> {
            marker: PhantomData<T>,
        }

        impl<'de, T: Deserialize<'de>> Visitor<'de> for OptionVisitor<T> {
            type Value = Option<T>;

            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                formatter.write_str("option")
            }

            #[inline]
            fn visit_unit<E>(self) -> Result<Option<T>, E>
            where
                E: Error,
            {
                Ok(None)
            }

            #[inline]
            fn visit_none<E>(self) -> Result<Option<T>, E>
            where
                E: Error,
            {
                Ok(None)
            }

            #[inline]
            fn visit_some<D>(self, deserializer: D) -> Result<Option<T>, D::Error>
            where
                D: Deserializer<'de>,
            {
                T::deserialize(deserializer).map(Some)
            }
        }

        deserializer.deserialize_option(OptionVisitor {
            marker: PhantomData,
        })
    }
}

#[cfg(feature = "chrono")]
impl<'de> Deserialize<'de> for chrono::Duration {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        serde::Deserialize::deserialize(deserializer)
            .map(|nanos| chrono::Duration::nanoseconds(nanos))
    }
}

#[cfg(feature = "chrono")]
impl<'de> Deserialize<'de> for Option<chrono::Duration> {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        struct OptionVisitor<T> {
            marker: PhantomData<T>,
        }

        impl<'de, T: Deserialize<'de>> Visitor<'de> for OptionVisitor<T> {
            type Value = Option<T>;

            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                formatter.write_str("option")
            }

            #[inline]
            fn visit_unit<E>(self) -> Result<Option<T>, E>
            where
                E: Error,
            {
                Ok(None)
            }

            #[inline]
            fn visit_none<E>(self) -> Result<Option<T>, E>
            where
                E: Error,
            {
                Ok(None)
            }

            #[inline]
            fn visit_some<D>(self, deserializer: D) -> Result<Option<T>, D::Error>
            where
                D: Deserializer<'de>,
            {
                T::deserialize(deserializer).map(Some)
            }
        }

        deserializer.deserialize_option(OptionVisitor {
            marker: PhantomData,
        })
    }
}