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
use std::collections::HashMap;
use bincode::{deserialize, serialize};
use super::*;
pub trait Storage: Clone {
fn get_highest_seen(&mut self, key: Key) -> Ballot;
fn get_accepted_ballot(&mut self, key: Key) -> Ballot;
fn get_accepted_value(&mut self, key: Key) -> Option<Value>;
fn set_highest_seen(&mut self, key: Key, ballot: Ballot);
fn set_accepted_ballot(&mut self, key: Key, ballot: Ballot);
fn set_accepted_value(&mut self, key: Key, value: Option<Value>);
}
const HIGHEST_SEEN_SUFFIX: u8 = 0;
const LAST_BALLOT_SUFFIX: u8 = 1;
const LAST_VALUE_SUFFIX: u8 = 2;
#[derive(Default, Clone)]
pub struct MemStorage {
inner: HashMap<Key, Value>,
}
impl Storage for MemStorage {
fn get_highest_seen(&mut self, mut k: Key) -> Ballot {
k.push(HIGHEST_SEEN_SUFFIX);
self.inner
.get(&k)
.cloned()
.map(|v| deserialize(&v[..]).unwrap())
.unwrap_or_else(|| Ballot::default())
}
fn get_accepted_ballot(&mut self, mut k: Key) -> Ballot {
k.push(LAST_BALLOT_SUFFIX);
self.inner
.get(&k)
.cloned()
.map(|v| deserialize(&v[..]).unwrap())
.unwrap_or_else(|| Ballot::default())
}
fn get_accepted_value(&mut self, mut k: Key) -> Option<Value> {
k.push(LAST_VALUE_SUFFIX);
self.inner.get(&k).cloned()
}
fn set_highest_seen(&mut self, mut k: Key, ballot: Ballot) {
k.push(HIGHEST_SEEN_SUFFIX);
let v = serialize(&ballot).unwrap();
self.inner.insert(k, v);
}
fn set_accepted_ballot(&mut self, mut k: Key, ballot: Ballot) {
k.push(LAST_BALLOT_SUFFIX);
let v = serialize(&ballot).unwrap();
self.inner.insert(k, v);
}
fn set_accepted_value(&mut self, mut k: Key, value: Option<Value>) {
k.push(LAST_VALUE_SUFFIX);
if let Some(v) = value {
self.inner.insert(k, v);
} else {
self.inner.remove(&k);
}
}
}
#[derive(Clone)]
pub struct SledStorage {
inner: sled::Tree,
}
impl SledStorage {
pub fn new(tree: sled::Tree) -> SledStorage {
SledStorage { inner: tree }
}
}
impl Storage for SledStorage {
fn get_highest_seen(&mut self, mut k: Key) -> Ballot {
k.push(HIGHEST_SEEN_SUFFIX);
self.inner
.get(&k)
.unwrap()
.map(|v| deserialize(&v[..]).unwrap())
.unwrap_or_else(|| Ballot::default())
}
fn get_accepted_ballot(&mut self, mut k: Key) -> Ballot {
k.push(LAST_BALLOT_SUFFIX);
self.inner
.get(&k)
.unwrap()
.map(|v| deserialize(&v[..]).unwrap())
.unwrap_or_else(|| Ballot::default())
}
fn get_accepted_value(&mut self, mut k: Key) -> Option<Value> {
k.push(LAST_VALUE_SUFFIX);
self.inner.get(&k).unwrap().map(|iv| iv.to_vec())
}
fn set_highest_seen(&mut self, mut k: Key, ballot: Ballot) {
k.push(HIGHEST_SEEN_SUFFIX);
let v = serialize(&ballot).unwrap();
self.inner.insert(k, v).unwrap();
}
fn set_accepted_ballot(&mut self, mut k: Key, ballot: Ballot) {
k.push(LAST_BALLOT_SUFFIX);
let v = serialize(&ballot).unwrap();
self.inner.insert(k, v).unwrap();
}
fn set_accepted_value(&mut self, mut k: Key, value: Option<Value>) {
k.push(LAST_VALUE_SUFFIX);
if let Some(v) = value {
self.inner.insert(k, v).unwrap();
} else {
self.inner.remove(&k).unwrap();
}
}
}