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

use crate::{
    core::entities::{EID, VID},
    db::api::{state::Index, view::Base},
};
use enum_dispatch::enum_dispatch;
use rayon::{iter::Either, prelude::*};
use std::sync::Arc;

#[enum_dispatch]
pub trait ListOps {
    fn node_list(&self) -> NodeList;

    fn edge_list(&self) -> EdgeList;
}

pub trait InheritListOps: Base {}

impl<G: InheritListOps> ListOps for G
where
    <G as Base>::Base: ListOps,
{
    fn node_list(&self) -> NodeList {
        self.base().node_list()
    }

    fn edge_list(&self) -> EdgeList {
        self.base().edge_list()
    }
}

#[derive(Debug, Clone)]
pub enum NodeList {
    All { num_nodes: usize },
    List { nodes: Index<VID> },
}

impl NodeList {
    pub fn par_iter(&self) -> impl IndexedParallelIterator<Item = VID> + '_ {
        match self {
            NodeList::All { num_nodes } => Either::Left((0..*num_nodes).into_par_iter().map(VID)),
            NodeList::List { nodes } => Either::Right(nodes.par_iter().copied()),
        }
    }

    pub fn into_par_iter(self) -> impl IndexedParallelIterator<Item = VID> {
        match self {
            NodeList::All { num_nodes } => Either::Left((0..num_nodes).into_par_iter().map(VID)),
            NodeList::List { nodes } => Either::Right(
                (0..nodes.len())
                    .into_par_iter()
                    .map(move |i| nodes.key(i).unwrap()),
            ),
        }
    }

    pub fn iter(&self) -> impl Iterator<Item = VID> + '_ {
        match self {
            NodeList::All { num_nodes } => Either::Left((0..*num_nodes).map(VID)),
            NodeList::List { nodes } => Either::Right(nodes.iter().copied()),
        }
    }

    pub fn len(&self) -> usize {
        match self {
            NodeList::All { num_nodes } => *num_nodes,
            NodeList::List { nodes } => nodes.len(),
        }
    }
}

impl IntoIterator for NodeList {
    type Item = VID;
    type IntoIter = Box<dyn Iterator<Item = Self::Item> + Send + Sync>;

    fn into_iter(self) -> Self::IntoIter {
        match self {
            NodeList::All { num_nodes } => Box::new((0..num_nodes).map(VID)),
            NodeList::List { nodes } => Box::new(nodes.into_iter()),
        }
    }
}

#[derive(Clone)]
pub enum EdgeList {
    All { num_edges: usize },
    List { edges: Arc<[EID]> },
}

impl EdgeList {
    pub fn par_iter(&self) -> impl IndexedParallelIterator<Item = EID> + '_ {
        match self {
            EdgeList::All { num_edges } => Either::Left((0..*num_edges).into_par_iter().map(EID)),
            EdgeList::List { edges } => Either::Right(edges.par_iter().copied()),
        }
    }

    pub fn into_par_iter(self) -> impl IndexedParallelIterator<Item = EID> {
        match self {
            EdgeList::All { num_edges } => Either::Left((0..num_edges).into_par_iter().map(EID)),
            EdgeList::List { edges } => {
                Either::Right((0..edges.len()).into_par_iter().map(move |i| edges[i]))
            }
        }
    }

    pub fn iter(&self) -> impl Iterator<Item = EID> + '_ {
        match self {
            EdgeList::All { num_edges } => Either::Left((0..*num_edges).map(EID)),
            EdgeList::List { edges } => Either::Right(edges.iter().copied()),
        }
    }

    pub fn len(&self) -> usize {
        match self {
            EdgeList::All { num_edges } => *num_edges,
            EdgeList::List { edges } => edges.len(),
        }
    }
}

impl IntoIterator for EdgeList {
    type Item = EID;
    type IntoIter = Box<dyn Iterator<Item = Self::Item> + Send + Sync>;

    fn into_iter(self) -> Self::IntoIter {
        match self {
            EdgeList::All { num_edges } => Box::new((0..num_edges).map(EID)),
            EdgeList::List { edges } => Box::new((0..edges.len()).map(move |i| edges[i])),
        }
    }
}