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
use std::{
io::{Error, ErrorKind, Result},
sync::{
atomic::{AtomicBool, Ordering},
Arc,
},
};
use crate::subnet::rpc::database::{self, iterator::BoxedIterator};
pub struct Iterator {
keys: Vec<Vec<u8>>,
values: Vec<Vec<u8>>,
initialized: AtomicBool,
error: Option<Error>,
closed: Arc<AtomicBool>,
}
impl Iterator {
pub fn new(keys: Vec<Vec<u8>>, values: Vec<Vec<u8>>, closed: Arc<AtomicBool>) -> BoxedIterator {
Box::new(Self {
keys,
values,
initialized: AtomicBool::new(false),
error: None,
closed,
})
}
}
#[tonic::async_trait]
impl database::iterator::Iterator for Iterator {
async fn next(&mut self) -> Result<bool> {
if self.closed.load(Ordering::Relaxed) {
self.keys = vec![];
self.values = vec![];
self.error = Some(Error::new(ErrorKind::Other, "database closed"));
return Ok(false);
}
if !self.initialized.load(Ordering::Relaxed) {
self.initialized.store(true, Ordering::Relaxed);
return Ok(self.keys.len() > 0);
}
if !self.keys.is_empty() {
self.keys.drain(0..1);
self.values.drain(0..1);
}
Ok(self.keys.len() > 0)
}
async fn error(&mut self) -> Result<()> {
if let Some(err) = &self.error {
return Err(Error::new(err.kind(), err.to_string()));
}
Ok(())
}
async fn key(&self) -> Result<&[u8]> {
if self.keys.is_empty() {
return Ok(&[]);
}
Ok(&self.keys[0])
}
async fn value(&self) -> Result<&[u8]> {
if self.values.is_empty() {
return Ok(&[]);
}
Ok(&self.values[0])
}
async fn release(&mut self) {
self.keys = vec![];
self.values = vec![];
}
}