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
|
//#![allow(unused_variables)]
extern crate rand;
use rand;
fn one_in_(n: usize) -> bool {
rand::thread_rng().gen_weighted_bool(n)
}
#[derive(Debug)]
struct File {
name: String,
data: Vec<u8>,
}
impl File {
fn new(name: &str) -> File {
File {
name: String::from(name),
data: Vec::new(),
}
}
fn new_with_data(name: &str, data: &Vec<u8>) -> File { // <1>
let mut f = File::new(name);
f.data = data.clone();
f
}
fn read(self: &File, save_to: &mut Vec<u8>) -> usize { // <2>
let mut tmp = self.data.clone();
let read_length = tmp.len();
save_to.reserve(read_length);
save_to.append(&mut tmp);
read_length
}
}
fn open(f: &mut File) -> Result<File, String> {
if one_in_(10_000) {
return Err(String::from("Permission denied"))
}
Some(f)
}
fn close(f: &mut File) -> Result<File, String> {
if one_in_(100_000) {
return Err(String::from("Interrupted by signal!"))
}
Some(f)
}
fn main() {
let f3_data: Vec<u8> = vec![114, 117, 115, 116, 33]; // <4>
let mut f3 = File::new_with_data("2.txt", &f3_data);
let mut buffer: Vec<u8> = vec![];
open(&mut f3);
let f3_length = f3.read(&mut buffer); // <5>
close(&mut f3);
let text = String::from_utf8_lossy(&buffer);
println!("{:?}", f3);
println!("{} is {} bytes long", &f3.name, f3_length);
println!("{}", text);
}
|
