microdb/data/
result.rs

1use std::io;
2
3use crate::MicroDB;
4
5use super::{ComObj, Path, RawObj};
6
7impl<T, E> RawObj for Result<T, E>
8where
9    T: RawObj,
10    E: RawObj,
11{
12    fn to_db(self) -> Vec<u8> {
13        let mut v = Vec::new();
14        match self {
15            Ok(x) => {
16                v.push(1);
17                v.append(&mut x.to_db());
18            }
19            Err(x) => {
20                v.push(0);
21                v.append(&mut x.to_db());
22            }
23        }
24        v
25    }
26
27    fn from_db(mut x: Vec<u8>) -> Option<Self> {
28        if x.is_empty() {
29            return None;
30        }
31        if x[0] == 0 && x.len() == 1 {
32            x.remove(0);
33            return E::from_db(x).map(|x| Err(x));
34        }
35        if x[0] == 1 {
36            x.remove(0);
37            return T::from_db(x).map(|x| Ok(x));
38        }
39        None
40    }
41}
42
43impl<T, E> ComObj for Result<T, E>
44where
45    T: ComObj,
46    E: ComObj,
47{
48    fn to_db<P: Path>(self, path: P, db: &MicroDB) -> Result<(), io::Error> {
49        db.set_raw(path.sub_path("type"), self.is_ok())?;
50        match self {
51            Ok(x) => db.set_com(path.sub_path("data"), x),
52            Err(x) => db.set_com(path.sub_path("data"), x),
53        }
54    }
55
56    fn remove<P: Path>(path: P, db: &MicroDB) -> Result<(), io::Error> {
57        db.remove_raw(path.sub_path("type"))?;
58        db.remove(path.sub_path("data"))?;
59        Ok(())
60    }
61
62    fn from_db<P: Path>(path: P, db: &MicroDB) -> Result<Option<Self>, io::Error> {
63        if let Some(x) = db.get_raw(path.sub_path("type"))? {
64            if x {
65                if let Some(data) = db.get_com(path.sub_path("data"))? {
66                    // found
67                    Ok(Some(Ok(data)))
68                } else {
69                    // broken
70                    Ok(None)
71                }
72            } else if let Some(data) = db.get_com(path.sub_path("data"))? {
73                // found
74                Ok(Some(Err(data)))
75            } else {
76                // broken
77                Ok(None)
78            }
79        } else {
80            // broken
81            Ok(None)
82        }
83    }
84
85    fn paths<P: Path>(path: P, _db: &MicroDB) -> Result<Vec<String>, io::Error> {
86        Ok(vec![path.sub_path("type"), path.sub_path("data")])
87    }
88}
microdb/data/result.rs

microdb/data/
result.rs
