evobench_tools/key_val_fs/
as_key.rs

1use std::borrow::Cow;
2
3/// A type that can be used as the key (i.e. converted to a file name)
4/// in a `KeyVal` database.
5pub trait AsKey: Sized {
6    /// Types implementing this trait can't have failing conversions!
7    /// If you want to use a key type with a fallible conversion, it
8    /// must have a conversion to a custom type that implements AsKey,
9    /// and *that* conversion will need to be fallible. The result
10    /// must never start with a `.` (leading dot is used for temporary
11    /// files), or contain the `/` or `\0` characters, must be at
12    /// least 1 and at most 254 bytes long, and *should* never contain
13    /// control characters (this could make it a pain for people to
14    /// use command line tools to work with the databases).
15    fn as_filename_str(&self) -> Cow<'_, str>;
16
17    /// Calls `as_filename_str` and asserts that the result complies
18    /// to the rules mentioned above, panics if it does not.
19    fn verified_as_filename_str(&self) -> Cow<'_, str> {
20        let s = self.as_filename_str();
21        let bytes = s.as_bytes();
22        assert!(bytes.len() <= 254);
23        assert!(bytes.len() >= 1);
24        assert!(bytes[0] != b'.');
25        assert!(!bytes.contains(&b'/'));
26        assert!(!bytes.contains(&b'\0'));
27        s
28    }
29
30    /// Must convert the output of `as_filename_str` back into a Self
31    /// equal to the original self. If not possible (e.g. a human
32    /// placed an invalid file), return None.
33    fn try_from_filename_str(file_name: &str) -> Option<Self>;
34}
evobench_tools/key_val_fs/as_key.rs

evobench_tools/key_val_fs/
as_key.rs
