-
Notifications
You must be signed in to change notification settings - Fork 1
/
demo.rs
87 lines (75 loc) · 2.79 KB
/
demo.rs
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
// MIT License
//
// Copyright (c) 2017 Anthony James Munns
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#[macro_use]
extern crate serde_derive;
extern crate mvdb;
use std::path::Path;
use mvdb::Mvdb;
use mvdb::errors::*;
#[derive(Deserialize, Serialize, Debug, Default)]
struct NotADb {
just_one: InnerData,
multiple: Vec<InnerData>,
}
#[derive(Deserialize, Serialize, Debug, Default)]
struct InnerData {
foo: String,
bar: Vec<u8>,
baz: String,
}
fn run() -> Result<()> {
// Create the database and storage file. If `demo.json` does not exist,
// it will be created with default values
let file = Path::new("demo.json");
let db: Mvdb<NotADb> = Mvdb::from_file_or_default(&file)?;
// Access the database contents atomically via a closure. You may
// optionally return a value (of any type) from the closure, which will
// be wrapped in a Result
let y = db.access(|data| {
// Data can be used immutably within the access
for i in data.multiple.iter() {
println!("baz: {}", i.baz);
}
// When returning data, it must be cloned, as references must not
// outlive the atomic lock
data.just_one.foo.clone()
})?;
println!("y: {:?}", y);
// Access the database contents atomically via a closure. You may
// optionally return a value (of any type) from the closure, which will
// be wrapped in a Result. Changes will be written if the database contents
// changed
let z = "thisisatest".into();
let x = InnerData {
foo: "tacos".into(),
bar: vec![0, 1, 2],
baz: "burritos".into(),
};
db.access_mut(|data: &mut NotADb| {
data.just_one.foo = z;
data.multiple.push(x);
})?;
Ok(())
}
fn main() {
assert!(run().is_ok());
}