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
extern crate bincode;
extern crate prototty_storage;
extern crate serde;
pub use prototty_storage::{LoadError, Storage, StoreError};
use serde::de::DeserializeOwned;
use serde::ser::Serialize;
use std::collections::HashMap;
pub trait StoreBytes {
fn store(&mut self, bytes: &[u8]);
}
pub struct MonoStorage<S: StoreBytes> {
table: HashMap<String, Vec<u8>>,
store_bytes: S,
}
impl<S: StoreBytes> MonoStorage<S> {
pub fn new(store_bytes: S) -> Self {
let table = HashMap::new();
Self { table, store_bytes }
}
pub fn from_bytes(bytes: &[u8], store_bytes: S) -> Option<Self> {
bincode::deserialize(bytes)
.ok()
.map(|table| Self { table, store_bytes })
}
pub fn from_bytes_or_empty(bytes: &[u8], store_bytes: S) -> Self {
match bincode::deserialize(bytes).ok() {
Some(table) => Self { table, store_bytes },
None => Self::new(store_bytes),
}
}
fn to_bytes(&self) -> Vec<u8> {
bincode::serialize(&self.table).expect("Failed to serialize")
}
fn sync(&mut self) {
let bytes = self.to_bytes();
self.store_bytes.store(&bytes);
}
}
impl<S: StoreBytes> Storage for MonoStorage<S> {
fn load<K, T>(&self, key: K) -> Result<T, LoadError>
where
K: AsRef<str>,
T: DeserializeOwned,
{
bincode::deserialize(self.load_raw(key)?.as_slice()).map_err(|_| LoadError::InvalidFormat)
}
fn remove<K, T>(&mut self, key: K) -> Result<T, LoadError>
where
K: AsRef<str>,
T: DeserializeOwned,
{
let bytes = self.remove_raw(key)?;
bincode::deserialize(&bytes).map_err(|_| LoadError::InvalidFormat)
}
fn load_raw<K>(&self, key: K) -> Result<Vec<u8>, LoadError>
where
K: AsRef<str>,
{
self.table
.get(key.as_ref())
.cloned()
.ok_or(LoadError::NoSuchKey)
}
fn store_raw<K, V>(&mut self, key: K, value: V) -> Result<(), StoreError>
where
K: AsRef<str>,
V: AsRef<[u8]>,
{
{
let slice = value.as_ref();
let buf = self
.table
.entry(key.as_ref().to_string())
.or_insert_with(Vec::new);
buf.resize(slice.len(), 0);
buf.copy_from_slice(slice);
}
self.sync();
Ok(())
}
fn remove_raw<K>(&mut self, key: K) -> Result<Vec<u8>, LoadError>
where
K: AsRef<str>,
{
let ret = self.table.remove(key.as_ref()).ok_or(LoadError::NoSuchKey);
self.sync();
ret
}
fn exists<K>(&self, key: K) -> bool
where
K: AsRef<str>,
{
self.table.contains_key(key.as_ref())
}
fn clear(&mut self) {
self.table.clear();
self.sync();
}
fn store<K, T>(&mut self, key: K, value: &T) -> Result<(), StoreError>
where
K: AsRef<str>,
T: Serialize,
{
let bytes = bincode::serialize(value).expect("Failed to serialize data");
self.store_raw(key, bytes)?;
Ok(())
}
}