asyncgit 0.2.1

allow using git2 in a asynchronous context
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

use crate::{hash, sync, AsyncNotification, FileDiff, CWD};
use crossbeam_channel::Sender;
use log::trace;
use std::{
    hash::Hash,
    sync::{
        atomic::{AtomicUsize, Ordering},
        Arc, Mutex,
    },
};

///
#[derive(Default, Hash, Clone, PartialEq)]
pub struct DiffParams(pub String, pub bool);

struct Request<R, A>(R, Option<A>);

#[derive(Default, Clone)]
struct LastResult<P, R> {
    params: P,
    hash: u64,
    result: R,
}

///
pub struct AsyncDiff {
    current: Arc<Mutex<Request<u64, FileDiff>>>,
    last: Arc<Mutex<Option<LastResult<DiffParams, FileDiff>>>>,
    sender: Sender<AsyncNotification>,
    pending: Arc<AtomicUsize>,
}

impl AsyncDiff {
    ///
    pub fn new(sender: Sender<AsyncNotification>) -> Self {
        Self {
            current: Arc::new(Mutex::new(Request(0, None))),
            last: Arc::new(Mutex::new(None)),
            sender,
            pending: Arc::new(AtomicUsize::new(0)),
        }
    }

    ///
    pub fn last(&mut self) -> Option<(DiffParams, FileDiff)> {
        let last = self.last.lock().unwrap();
        if let Some(res) = last.clone() {
            Some((res.params, res.result))
        } else {
            None
        }
    }

    ///
    pub fn refresh(&mut self) {
        if let Some(param) = self.get_last_param() {
            self.clear_current();
            self.request(param);
        }
    }

    ///
    pub fn is_pending(&self) -> bool {
        self.pending.load(Ordering::Relaxed) > 0
    }

    ///
    pub fn request(
        &mut self,
        params: DiffParams,
    ) -> Option<FileDiff> {
        trace!("request");

        let hash = hash(&params);

        {
            let mut current = self.current.lock().unwrap();

            if current.0 == hash {
                return current.1.clone();
            }

            current.0 = hash;
            current.1 = None;
        }

        let arc_current = Arc::clone(&self.current);
        let arc_last = Arc::clone(&self.last);
        let sender = self.sender.clone();
        let arc_pending = Arc::clone(&self.pending);
        rayon_core::spawn(move || {
            arc_pending.fetch_add(1, Ordering::Relaxed);

            let res =
                sync::diff::get_diff(CWD, params.0.clone(), params.1);
            let mut notify = false;
            {
                let mut current = arc_current.lock().unwrap();
                if current.0 == hash {
                    current.1 = Some(res.clone());
                    notify = true;
                }
            }

            {
                let mut last = arc_last.lock().unwrap();
                *last = Some(LastResult {
                    result: res,
                    hash,
                    params,
                });
            }

            arc_pending.fetch_sub(1, Ordering::Relaxed);

            if notify {
                sender
                    .send(AsyncNotification::Diff)
                    .expect("error sending diff");
            }
        });

        None
    }

    fn get_last_param(&self) -> Option<DiffParams> {
        self.last.lock().unwrap().clone().map(|e| e.params)
    }

    fn clear_current(&mut self) {
        let mut current = self.current.lock().unwrap();
        current.0 = 0;
        current.1 = None;
    }
}