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
use super::plumbing::*;
use super::ParallelIterator;
pub(super) fn reduce<PI, R, ID, T>(pi: PI, identity: ID, reduce_op: R) -> T
where
PI: ParallelIterator<Item = T>,
R: Fn(T, T) -> T + Sync,
ID: Fn() -> T + Sync,
T: Send,
{
let consumer = ReduceConsumer {
identity: &identity,
reduce_op: &reduce_op,
};
pi.drive_unindexed(consumer)
}
struct ReduceConsumer<'r, R, ID> {
identity: &'r ID,
reduce_op: &'r R,
}
impl<'r, R, ID> Copy for ReduceConsumer<'r, R, ID> {}
impl<'r, R, ID> Clone for ReduceConsumer<'r, R, ID> {
fn clone(&self) -> Self {
*self
}
}
impl<'r, R, ID, T> Consumer<T> for ReduceConsumer<'r, R, ID>
where
R: Fn(T, T) -> T + Sync,
ID: Fn() -> T + Sync,
T: Send,
{
type Folder = ReduceFolder<'r, R, T>;
type Reducer = Self;
type Result = T;
fn split_at(self, _index: usize) -> (Self, Self, Self) {
(self, self, self)
}
fn into_folder(self) -> Self::Folder {
ReduceFolder {
reduce_op: self.reduce_op,
item: (self.identity)(),
}
}
fn full(&self) -> bool {
false
}
}
impl<'r, R, ID, T> UnindexedConsumer<T> for ReduceConsumer<'r, R, ID>
where
R: Fn(T, T) -> T + Sync,
ID: Fn() -> T + Sync,
T: Send,
{
fn split_off_left(&self) -> Self {
*self
}
fn to_reducer(&self) -> Self::Reducer {
*self
}
}
impl<'r, R, ID, T> Reducer<T> for ReduceConsumer<'r, R, ID>
where
R: Fn(T, T) -> T + Sync,
{
fn reduce(self, left: T, right: T) -> T {
(self.reduce_op)(left, right)
}
}
struct ReduceFolder<'r, R, T> {
reduce_op: &'r R,
item: T,
}
impl<'r, R, T> Folder<T> for ReduceFolder<'r, R, T>
where
R: Fn(T, T) -> T,
{
type Result = T;
fn consume(self, item: T) -> Self {
ReduceFolder {
reduce_op: self.reduce_op,
item: (self.reduce_op)(self.item, item),
}
}
fn consume_iter<I>(self, iter: I) -> Self
where
I: IntoIterator<Item = T>,
{
ReduceFolder {
reduce_op: self.reduce_op,
item: iter.into_iter().fold(self.item, self.reduce_op),
}
}
fn complete(self) -> T {
self.item
}
fn full(&self) -> bool {
false
}
}