rayon/iter/
try_reduce.rs

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1use super::plumbing::*;
2use super::ParallelIterator;
3
4use super::private::Try;
5use std::sync::atomic::{AtomicBool, Ordering};
6
7pub(super) fn try_reduce<PI, R, ID, T>(pi: PI, identity: ID, reduce_op: R) -> T
8where
9    PI: ParallelIterator<Item = T>,
10    R: Fn(T::Ok, T::Ok) -> T + Sync,
11    ID: Fn() -> T::Ok + Sync,
12    T: Try + Send,
13{
14    let full = AtomicBool::new(false);
15    let consumer = TryReduceConsumer {
16        identity: &identity,
17        reduce_op: &reduce_op,
18        full: &full,
19    };
20    pi.drive_unindexed(consumer)
21}
22
23struct TryReduceConsumer<'r, R, ID> {
24    identity: &'r ID,
25    reduce_op: &'r R,
26    full: &'r AtomicBool,
27}
28
29impl<'r, R, ID> Copy for TryReduceConsumer<'r, R, ID> {}
30
31impl<'r, R, ID> Clone for TryReduceConsumer<'r, R, ID> {
32    fn clone(&self) -> Self {
33        *self
34    }
35}
36
37impl<'r, R, ID, T> Consumer<T> for TryReduceConsumer<'r, R, ID>
38where
39    R: Fn(T::Ok, T::Ok) -> T + Sync,
40    ID: Fn() -> T::Ok + Sync,
41    T: Try + Send,
42{
43    type Folder = TryReduceFolder<'r, R, T>;
44    type Reducer = Self;
45    type Result = T;
46
47    fn split_at(self, _index: usize) -> (Self, Self, Self) {
48        (self, self, self)
49    }
50
51    fn into_folder(self) -> Self::Folder {
52        TryReduceFolder {
53            reduce_op: self.reduce_op,
54            result: Ok((self.identity)()),
55            full: self.full,
56        }
57    }
58
59    fn full(&self) -> bool {
60        self.full.load(Ordering::Relaxed)
61    }
62}
63
64impl<'r, R, ID, T> UnindexedConsumer<T> for TryReduceConsumer<'r, R, ID>
65where
66    R: Fn(T::Ok, T::Ok) -> T + Sync,
67    ID: Fn() -> T::Ok + Sync,
68    T: Try + Send,
69{
70    fn split_off_left(&self) -> Self {
71        *self
72    }
73
74    fn to_reducer(&self) -> Self::Reducer {
75        *self
76    }
77}
78
79impl<'r, R, ID, T> Reducer<T> for TryReduceConsumer<'r, R, ID>
80where
81    R: Fn(T::Ok, T::Ok) -> T + Sync,
82    T: Try,
83{
84    fn reduce(self, left: T, right: T) -> T {
85        match (left.into_result(), right.into_result()) {
86            (Ok(left), Ok(right)) => (self.reduce_op)(left, right),
87            (Err(e), _) | (_, Err(e)) => T::from_error(e),
88        }
89    }
90}
91
92struct TryReduceFolder<'r, R, T: Try> {
93    reduce_op: &'r R,
94    result: Result<T::Ok, T::Error>,
95    full: &'r AtomicBool,
96}
97
98impl<'r, R, T> Folder<T> for TryReduceFolder<'r, R, T>
99where
100    R: Fn(T::Ok, T::Ok) -> T,
101    T: Try,
102{
103    type Result = T;
104
105    fn consume(mut self, item: T) -> Self {
106        let reduce_op = self.reduce_op;
107        if let Ok(left) = self.result {
108            self.result = match item.into_result() {
109                Ok(right) => reduce_op(left, right).into_result(),
110                Err(error) => Err(error),
111            };
112        }
113        if self.result.is_err() {
114            self.full.store(true, Ordering::Relaxed)
115        }
116        self
117    }
118
119    fn complete(self) -> T {
120        match self.result {
121            Ok(ok) => T::from_ok(ok),
122            Err(error) => T::from_error(error),
123        }
124    }
125
126    fn full(&self) -> bool {
127        self.full.load(Ordering::Relaxed)
128    }
129}
rayon/iter/try_reduce.rs

rayon/iter/
try_reduce.rs
