feat(tazjin/german-string): add data accessors for &str and &[u8]

Change-Id: I992e625861f79ef6d9993e8caee4e02d3fc5557e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12236
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: tazjin <tazjin@tvl.su>
This commit is contained in:
Vincent Ambo 2024-08-16 16:09:06 +03:00 committed by clbot
parent 4d5abbe232
commit d8640b6e67

View file

@ -66,11 +66,23 @@ impl GermanString {
}
}
fn len(&self) -> usize {
pub fn len(&self) -> usize {
// SAFETY: The length field is located in the same location for both
// variants, reading it from either is safe.
unsafe { self.0.small.len as usize }
}
pub fn as_bytes(&self) -> &[u8] {
if self.len() > 12 {
unsafe { std::slice::from_raw_parts(self.0.large.data, self.len()) }
} else {
unsafe { &self.0.small.data.as_ref()[..self.len()] }
}
}
pub fn as_str(&self) -> Result<&str, std::str::Utf8Error> {
std::str::from_utf8(self.as_bytes())
}
}
impl Drop for GermanString {
@ -83,3 +95,57 @@ impl Drop for GermanString {
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_empty_string() {
let empty = GermanString::new_transient(b"");
assert_eq!(empty.len(), 0, "empty string should be empty");
assert_eq!(empty.as_bytes(), b"", "empty string should contain nothing");
assert_eq!(
empty.as_str().expect("empty string is valid UTF-8"),
"",
"empty string should contain empty string"
);
}
#[test]
fn test_short_string() {
let short = GermanString::new_transient(b"meow");
assert_eq!(short.len(), 4, "'meow' is four characters");
assert_eq!(
short.as_bytes(),
b"meow",
"short string returns correct bytes"
);
assert_eq!(
short.as_str().expect("'meow' is valid UTF-8"),
"meow",
"short string returns correct string"
);
}
#[test]
fn test_long_string() {
let input: &str = "This code was written at https://signal.live";
let long = GermanString::new_transient(input.as_bytes());
assert_eq!(long.len(), 44, "long string has correct length");
assert_eq!(
long.as_bytes(),
input.as_bytes(),
"long string returns correct bytes"
);
assert_eq!(
long.as_str().expect("input is valid UTF-8"),
input,
"long string returns correct string"
);
}
}