wolf-graph 0.1.0

Data structures and algorithms for working with graphs with reference or value semantics.
Documentation 
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
133
134
135
136
137
138
139
140

use std::borrow::Cow;

#[cfg(feature = "serde")]
use serde::{ser::{Serialize, Serializer}, de::{Deserialize, Deserializer}};

use crate::{EdgeID, NodeID};

#[derive(Clone, Debug, PartialEq)]
pub struct Edge<EData>
where
    EData: Clone + 'static,
{
    pub id: EdgeID,
    pub source: NodeID,
    pub target: NodeID,
    pub data: Cow<'static, EData>,
}

impl<EData> Edge<EData>
where
    EData: Clone + 'static,
{
    pub fn new(id: EdgeID, source: NodeID, target: NodeID, data: EData) -> Self {
        Edge {
            id,
            source,
            target,
            data: Cow::Owned(data),
        }
    }

    pub fn setting_data(&self, data: EData) -> Self {
        Edge {
            id: self.id.clone(),
            source: self.source.clone(),
            target: self.target.clone(),
            data: Cow::Owned(data),
        }
    }
}

#[cfg(feature = "serde")]
impl<EData> Serialize for Edge<EData>
where
    EData: Clone + Serialize + 'static,
{
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        if std::mem::size_of::<EData>() == 0 {
            (&self.id, &self.source, &self.target).serialize(serializer)
        } else {
            (&self.id, &self.source, &self.target, &self.data).serialize(serializer)
        }
    }
}

#[cfg(feature = "serde")]
impl<'de, EData> Deserialize<'de> for Edge<EData>
where
    EData: Clone + Deserialize<'de> + 'static + Default,
{
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        if std::mem::size_of::<EData>() == 0 {
            let (id, source, target) = <(EdgeID, NodeID, NodeID)>::deserialize(deserializer)?;
            Ok(Edge::new(id, source, target, EData::default()))
        } else {
            let (id, source, target, data) = <(EdgeID, NodeID, NodeID, EData)>::deserialize(deserializer)?;
            Ok(Edge::new(id, source, target, data))
        }
    }
}

#[cfg(all(test, feature = "serde", feature = "serde_json"))]
mod tests {
    use crate::{eid, nid};

    use super::*;
    use serde_test::{assert_tokens, Token};
    use std::borrow::Cow;

    #[test]
    fn edge_with_data_round_trip() {
        let edge: Edge<i32> = Edge::<i32> {
            id: eid!("EdgeID"),
            source: nid!("Source"),
            target: nid!("Target"),
            data: Cow::Owned(42),
        };

        assert_tokens(
            &edge,
            &[
                Token::Tuple { len: 4 },
                Token::Str("EdgeID"),
                Token::Str("Source"),
                Token::Str("Target"),
                Token::I32(42),
                Token::TupleEnd,
            ],
        );

        let json = serde_json::to_string(&edge).unwrap();
        assert_eq!(json, r#"["EdgeID","Source","Target",42]"#);

        let deserialized_edge: Edge<i32> = serde_json::from_str(&json).unwrap();
        assert_eq!(deserialized_edge, edge);
    }

    #[test]
    fn edge_with_unit_data_round_trip() {
        let edge: Edge<()> = Edge {
            id: eid!("EdgeID"),
            source: nid!("Source"),
            target: nid!("Target"),
            data: Cow::Owned(()),
        };

        assert_tokens(
            &edge,
            &[
                Token::Tuple { len: 3 },
                Token::Str("EdgeID"),
                Token::Str("Source"),
                Token::Str("Target"),
                Token::TupleEnd,
            ],
        );

        let json = serde_json::to_string(&edge).unwrap();
        assert_eq!(json, r#"["EdgeID","Source","Target"]"#);

        let deserialized_edge: Edge<()> = serde_json::from_str(&json).unwrap();
        assert_eq!(deserialized_edge, edge);
    }
}