respect meta max len of 1024 in constructors

This commit is contained in:
panicbit 2020-11-14 02:54:34 +01:00
parent 73a5c4007d
commit 82dc34b2c5
2 changed files with 62 additions and 9 deletions

View file

@ -8,9 +8,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
### Added ### Added
- `GEMINI_MIME_STR`, the `&str` representation of the Gemini MIME - `GEMINI_MIME_STR`, the `&str` representation of the Gemini MIME
- `Meta::new_lossy` constructor that never fails - `Meta::new_lossy` constructor that never fails
- `Meta::MAX_LEN`, which is `1024`
- "lossy" constructors for `Response` and `Status` (see `Meta::new_lossy`) - "lossy" constructors for `Response` and `Status` (see `Meta::new_lossy`)
### Changed ### Changed
- `Meta::new` rejects strings exceeding `Meta::MAX_LEN` (`1024`)
- Some `Response` and `Status` constructors are now infallible - Some `Response` and `Status` constructors are now infallible
### Deprecated ### Deprecated

View file

@ -232,9 +232,12 @@ impl StatusCategory {
pub struct Meta(String); pub struct Meta(String);
impl Meta { impl Meta {
pub const MAX_LEN: usize = 1024;
/// Creates a new "Meta" string. Fails if `meta` contains `\n`. /// Creates a new "Meta" string. Fails if `meta` contains `\n`.
pub fn new(meta: impl AsRef<str> + Into<String>) -> Result<Self> { pub fn new(meta: impl AsRef<str> + Into<String>) -> Result<Self> {
ensure!(!meta.as_ref().contains("\n"), "Meta must not contain newlines"); ensure!(!meta.as_ref().contains("\n"), "Meta must not contain newlines");
ensure!(meta.as_ref().len() <= Self::MAX_LEN, "Meta must not exceed {} bytes", Self::MAX_LEN);
Ok(Self(meta.into())) Ok(Self(meta.into()))
} }
@ -242,16 +245,19 @@ impl Meta {
/// Cretaes a new "Meta" string. Truncates `meta` to before the first occurrence of `\n`. /// Cretaes a new "Meta" string. Truncates `meta` to before the first occurrence of `\n`.
pub fn new_lossy(meta: impl AsRef<str> + Into<String>) -> Self { pub fn new_lossy(meta: impl AsRef<str> + Into<String>) -> Self {
let meta = meta.as_ref(); let meta = meta.as_ref();
let newline_pos = meta.char_indices().position(|(_i, ch)| ch == '\n'); let truncate_pos = meta.char_indices().position(|(i, ch)| {
let is_newline = ch == '\n';
let exceeds_limit = (i + ch.len_utf8()) > Self::MAX_LEN;
match newline_pos { is_newline || exceeds_limit
None => Self(meta.into()), });
Some(newline_pos) => {
let meta = meta.get(..newline_pos).expect("northstar BUG");
Self(meta.into()) let meta: String = match truncate_pos {
} None => meta.into(),
} Some(truncate_pos) => meta.get(..truncate_pos).expect("northstar BUG").into(),
};
Self(meta)
} }
pub fn empty() -> Self { pub fn empty() -> Self {
@ -368,6 +374,31 @@ impl From<File> for Body {
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use super::*; use super::*;
use std::iter::repeat;
#[test]
fn meta_new_rejects_newlines() {
let meta = "foo\nbar";
let meta = Meta::new(meta);
assert!(meta.is_err());
}
#[test]
fn meta_new_accepts_max_len() {
let meta: String = repeat('x').take(Meta::MAX_LEN).collect();
let meta = Meta::new(meta);
assert!(meta.is_ok());
}
#[test]
fn meta_new_rejects_exceeding_max_len() {
let meta: String = repeat('x').take(Meta::MAX_LEN + 1).collect();
let meta = Meta::new(meta);
assert!(meta.is_err());
}
#[test] #[test]
fn meta_new_lossy_truncates() { fn meta_new_lossy_truncates() {
@ -393,11 +424,31 @@ mod tests {
assert_eq!(meta.as_str(), ""); assert_eq!(meta.as_str(), "");
} }
#[test] #[test]
fn meta_new_lossy_truncates_to_empty() { fn meta_new_lossy_truncates_to_empty() {
let meta = "\n\n\n"; let meta = "\n\n\n";
let meta = Meta::new_lossy(meta); let meta = Meta::new_lossy(meta);
assert_eq!(meta.as_str(), ""); assert_eq!(meta.as_str(), "");
} }
#[test]
fn meta_new_lossy_truncates_to_max_len() {
let meta: String = repeat('x').take(Meta::MAX_LEN + 1).collect();
let meta = Meta::new_lossy(meta);
assert_eq!(meta.as_str().len(), Meta::MAX_LEN);
}
#[test]
fn meta_new_lossy_truncates_multi_byte_sequences() {
let mut meta: String = repeat('x').take(Meta::MAX_LEN - 1).collect();
meta.push('🦀');
assert_eq!(meta.len(), Meta::MAX_LEN + 3);
let meta = Meta::new_lossy(meta);
assert_eq!(meta.as_str().len(), Meta::MAX_LEN - 1);
}
} }