ntex_bytes/
string.rs

1//! A UTF-8 encoded read-only string using Bytes as storage.
2use std::{borrow, fmt, hash, ops, slice, str, sync::Arc};
3
4use crate::{Bytes, BytesMut};
5
6/// An immutable UTF-8 encoded string with [`Bytes`] as a storage.
7#[derive(Clone, Default, Eq, PartialOrd, Ord)]
8pub struct ByteString(Bytes);
9
10impl ByteString {
11    /// Creates a new empty `ByteString`.
12    #[inline]
13    #[must_use]
14    pub const fn new() -> Self {
15        ByteString(Bytes::new())
16    }
17
18    /// Get a str slice.
19    #[inline]
20    pub fn as_str(&self) -> &str {
21        self
22    }
23
24    /// Get a reference to the underlying bytes.
25    #[inline]
26    pub fn as_slice(&self) -> &[u8] {
27        self.0.as_ref()
28    }
29
30    /// Get a reference to the underlying `Bytes` object.
31    #[inline]
32    pub fn as_bytes(&self) -> &Bytes {
33        &self.0
34    }
35
36    /// Unwraps this `ByteString` into the underlying `Bytes` object.
37    #[inline]
38    #[must_use]
39    pub fn into_bytes(self) -> Bytes {
40        self.0
41    }
42
43    /// Creates a new `ByteString` from a `&'static str`.
44    #[inline]
45    #[must_use]
46    pub const fn from_static(src: &'static str) -> ByteString {
47        Self(Bytes::from_static(src.as_bytes()))
48    }
49
50    /// Returns a slice of self for the provided range.
51    ///
52    /// This will increment the reference count for the underlying memory and
53    /// return a new `ByteString` handle set to the slice.
54    ///
55    /// This operation is `O(1)`.
56    ///
57    /// # Examples
58    ///
59    /// ```
60    /// use ntex_bytes::ByteString;
61    ///
62    /// let a = ByteString::from("hello world");
63    /// let b = a.slice(2..5);
64    ///
65    /// assert_eq!(b, "llo");
66    /// ```
67    ///
68    /// # Panics
69    ///
70    /// Requires that `begin <= end` and `end <= self.len()`, otherwise slicing
71    /// will panic.
72    #[must_use]
73    pub fn slice(
74        &self,
75        range: impl ops::RangeBounds<usize> + slice::SliceIndex<str> + Clone,
76    ) -> ByteString {
77        ops::Index::index(self.as_ref(), range.clone());
78        ByteString(self.0.slice(range))
79    }
80
81    /// Splits the bytestring into two at the given index.
82    ///
83    /// Afterwards `self` contains elements `[0, at)`, and the returned `ByteString`
84    /// contains elements `[at, len)`.
85    ///
86    /// This is an `O(1)` operation that just increases the reference count and
87    /// sets a few indices.
88    ///
89    /// # Examples
90    ///
91    /// ```
92    /// use ntex_bytes::ByteString;
93    ///
94    /// let mut a = ByteString::from("hello world");
95    /// let b = a.split_off(5);
96    ///
97    /// assert_eq!(a, "hello");
98    /// assert_eq!(b, " world");
99    /// ```
100    ///
101    /// # Panics
102    ///
103    /// Panics if `at > len`.
104    #[must_use]
105    pub fn split_off(&mut self, at: usize) -> ByteString {
106        // check str
107        let _ = self.split_at(at);
108
109        ByteString(self.0.split_off(at))
110    }
111
112    /// Splits the bytestring into two at the given index.
113    ///
114    /// Afterwards `self` contains elements `[at, len)`, and the returned
115    /// `Bytes` contains elements `[0, at)`.
116    ///
117    /// This is an `O(1)` operation that just increases the reference count and
118    /// sets a few indices.
119    ///
120    /// # Examples
121    ///
122    /// ```
123    /// use ntex_bytes::ByteString;
124    ///
125    /// let mut a = ByteString::from("hello world");
126    /// let b = a.split_to(5);
127    ///
128    /// assert_eq!(a, " world");
129    /// assert_eq!(b, "hello");
130    /// ```
131    ///
132    /// # Panics
133    ///
134    /// Panics if `at > len`.
135    #[must_use]
136    pub fn split_to(&mut self, at: usize) -> ByteString {
137        // check str
138        let _ = self.split_at(at);
139
140        ByteString(self.0.split_to(at))
141    }
142
143    /// Shortens the buffer to `len` bytes and dropping the rest.
144    #[inline]
145    pub fn trimdown(&mut self) {
146        self.0.trimdown();
147    }
148
149    /// Clears the buffer, removing all data.
150    ///
151    /// # Examples
152    ///
153    /// ```
154    /// use ntex_bytes::ByteString;
155    ///
156    /// let mut a = ByteString::from("hello world");
157    /// a.clear();
158    ///
159    /// assert!(a.is_empty());
160    /// ```
161    #[inline]
162    pub fn clear(&mut self) {
163        self.0.clear();
164    }
165
166    /// Creates a new `ByteString` from a Bytes.
167    ///
168    /// # Safety
169    /// This function is unsafe because it does not check the bytes passed to it are valid UTF-8.
170    /// If this constraint is violated, it may cause memory unsafety issues with future users of
171    /// the `ByteString`, as we assume that `ByteString`s are valid UTF-8. However, the most likely
172    /// issue is that the data gets corrupted.
173    #[inline]
174    pub const unsafe fn from_bytes_unchecked(src: Bytes) -> ByteString {
175        Self(src)
176    }
177}
178
179impl PartialEq<str> for ByteString {
180    fn eq(&self, other: &str) -> bool {
181        &self[..] == other
182    }
183}
184
185impl<T: AsRef<str>> PartialEq<T> for ByteString {
186    fn eq(&self, other: &T) -> bool {
187        &self[..] == other.as_ref()
188    }
189}
190
191impl PartialEq<ByteString> for &ByteString {
192    fn eq(&self, other: &ByteString) -> bool {
193        self.as_str() == other.as_str()
194    }
195}
196
197impl PartialEq<ByteString> for str {
198    fn eq(&self, other: &ByteString) -> bool {
199        self == other.as_str()
200    }
201}
202
203impl PartialEq<ByteString> for &str {
204    fn eq(&self, other: &ByteString) -> bool {
205        *self == other.as_str()
206    }
207}
208
209impl AsRef<str> for ByteString {
210    #[inline]
211    fn as_ref(&self) -> &str {
212        self
213    }
214}
215
216impl hash::Hash for ByteString {
217    fn hash<H: hash::Hasher>(&self, state: &mut H) {
218        (**self).hash(state);
219    }
220}
221
222impl ops::Deref for ByteString {
223    type Target = str;
224
225    #[inline]
226    fn deref(&self) -> &str {
227        let bytes = self.0.as_ref();
228        // SAFETY:
229        // UTF-8 validity is guaranteed during construction.
230        unsafe { str::from_utf8_unchecked(bytes) }
231    }
232}
233
234impl borrow::Borrow<str> for ByteString {
235    #[inline]
236    fn borrow(&self) -> &str {
237        self
238    }
239}
240
241impl From<String> for ByteString {
242    #[inline]
243    fn from(value: String) -> Self {
244        Self(Bytes::from(value))
245    }
246}
247
248impl From<&str> for ByteString {
249    #[inline]
250    fn from(value: &str) -> Self {
251        Self(Bytes::copy_from_slice(value.as_ref()))
252    }
253}
254
255impl From<&ByteString> for ByteString {
256    #[inline]
257    fn from(value: &ByteString) -> Self {
258        value.clone()
259    }
260}
261
262impl<'a> From<borrow::Cow<'a, str>> for ByteString {
263    #[inline]
264    fn from(value: borrow::Cow<'a, str>) -> Self {
265        match value {
266            borrow::Cow::Owned(s) => Self::from(s),
267            borrow::Cow::Borrowed(s) => Self::from(s),
268        }
269    }
270}
271
272impl From<Arc<str>> for ByteString {
273    #[inline]
274    fn from(value: Arc<str>) -> Self {
275        ByteString::from_ext(value)
276    }
277}
278
279impl TryFrom<&[u8]> for ByteString {
280    type Error = ();
281
282    #[inline]
283    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
284        if utf8::is_valid(value) {
285            Ok(ByteString(Bytes::copy_from_slice(value)))
286        } else {
287            Err(())
288        }
289    }
290}
291
292impl TryFrom<Vec<u8>> for ByteString {
293    type Error = ();
294
295    #[inline]
296    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
297        if utf8::is_valid(&value) {
298            Ok(ByteString(Bytes::from(value)))
299        } else {
300            Err(())
301        }
302    }
303}
304
305impl TryFrom<Bytes> for ByteString {
306    type Error = ();
307
308    #[inline]
309    fn try_from(value: Bytes) -> Result<Self, Self::Error> {
310        if utf8::is_valid(&value) {
311            Ok(ByteString(value))
312        } else {
313            Err(())
314        }
315    }
316}
317
318impl TryFrom<&Bytes> for ByteString {
319    type Error = ();
320
321    #[inline]
322    fn try_from(value: &Bytes) -> Result<Self, Self::Error> {
323        if utf8::is_valid(value) {
324            Ok(ByteString(value.clone()))
325        } else {
326            Err(())
327        }
328    }
329}
330
331impl TryFrom<BytesMut> for ByteString {
332    type Error = ();
333
334    #[inline]
335    fn try_from(value: BytesMut) -> Result<Self, Self::Error> {
336        if utf8::is_valid(&value) {
337            Ok(ByteString(value.freeze()))
338        } else {
339            Err(())
340        }
341    }
342}
343
344impl fmt::Debug for ByteString {
345    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
346        (**self).fmt(fmt)
347    }
348}
349
350impl fmt::Display for ByteString {
351    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
352        (**self).fmt(fmt)
353    }
354}
355
356mod serde {
357    use serde::de::{Deserialize, Deserializer};
358    use serde::ser::{Serialize, Serializer};
359
360    use super::ByteString;
361
362    impl Serialize for ByteString {
363        #[inline]
364        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
365        where
366            S: Serializer,
367        {
368            serializer.serialize_str(self.as_ref())
369        }
370    }
371
372    impl<'de> Deserialize<'de> for ByteString {
373        #[inline]
374        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
375        where
376            D: Deserializer<'de>,
377        {
378            String::deserialize(deserializer).map(ByteString::from)
379        }
380    }
381}
382
383#[cfg(feature = "simd")]
384mod utf8 {
385    pub(super) fn is_valid(input: &[u8]) -> bool {
386        simdutf8::basic::from_utf8(input).is_ok()
387    }
388}
389
390#[cfg(not(feature = "simd"))]
391mod utf8 {
392    pub(super) fn is_valid(input: &[u8]) -> bool {
393        std::str::from_utf8(input).is_ok()
394    }
395}
396
397#[cfg(test)]
398mod test {
399    use std::borrow::{Borrow, Cow};
400    use std::collections::hash_map::DefaultHasher;
401    use std::hash::{Hash, Hasher};
402
403    use super::*;
404
405    #[test]
406    fn test_basics() {
407        let mut s = ByteString::from_static("test");
408        s.trimdown();
409        assert_eq!(s, "test");
410        assert_eq!(s, *"test");
411        assert_eq!(s, "test".to_owned());
412        assert_eq!(s.as_str(), "test");
413        assert_eq!(s.as_slice(), b"test");
414        assert_eq!(s.as_bytes(), &Bytes::copy_from_slice(b"test"));
415        assert_eq!(Borrow::<str>::borrow(&s), "test");
416        assert_eq!("test", s);
417        assert_eq!("test", &s);
418
419        assert_eq!(format!("{s}"), "test");
420        assert_eq!(format!("{s:?}"), "\"test\"");
421
422        let b = s.into_bytes();
423        assert_eq!(b, Bytes::copy_from_slice(b"test"));
424
425        let s = unsafe { ByteString::from_bytes_unchecked(b) };
426        assert_eq!(s, "test");
427        assert_eq!(s.slice(0..2), "te");
428
429        let s = ByteString::from(Cow::Borrowed("test"));
430        assert_eq!(s, "test");
431        let mut s = ByteString::from(Cow::Owned("test".to_string()));
432        assert_eq!(s, "test");
433
434        s.clear();
435        assert_eq!(s, "");
436    }
437
438    #[test]
439    fn test_split() {
440        let mut s = ByteString::from_static("helloworld");
441        let s1 = s.split_off(5);
442        assert_eq!(s, "hello");
443        assert_eq!(s1, "world");
444
445        let mut s = ByteString::from_static("helloworld");
446        let s1 = s.split_to(5);
447        assert_eq!(s, "world");
448        assert_eq!(s1, "hello");
449    }
450
451    #[test]
452    fn test_new() {
453        let _: ByteString = ByteString::new();
454    }
455
456    #[test]
457    fn test_hash() {
458        let mut hasher1 = DefaultHasher::default();
459        "str".hash(&mut hasher1);
460
461        let mut hasher2 = DefaultHasher::default();
462        let s = ByteString::from_static("str");
463        s.hash(&mut hasher2);
464        assert_eq!(hasher1.finish(), hasher2.finish());
465    }
466
467    #[test]
468    #[allow(clippy::items_after_statements)]
469    fn test_from() {
470        // String
471        let s: ByteString = "hello".to_owned().into();
472        assert_eq!(&s, "hello");
473        let t: &str = s.as_ref();
474        assert_eq!(t, "hello");
475
476        // str
477        let _: ByteString = "str".into();
478
479        // static str
480        static _S: ByteString = ByteString::from_static("hello");
481        let _ = ByteString::from_static("str");
482
483        let s = ByteString::from_static("hello");
484        let s1 = ByteString::from(&s);
485        assert_eq!(s1, "hello");
486    }
487
488    #[test]
489    fn test_try_from() {
490        let _ = ByteString::try_from(&b"nice bytes"[..]).unwrap();
491        assert!(ByteString::try_from(b"\xc3\x28".as_ref()).is_err());
492
493        let _ = ByteString::try_from(b"nice bytes".to_vec()).unwrap();
494        assert!(ByteString::try_from(vec![b'\xc3']).is_err());
495
496        let _ = ByteString::try_from(Bytes::from_static(b"nice bytes")).unwrap();
497        assert!(ByteString::try_from(Bytes::from_static(b"\xc3\x28")).is_err());
498
499        let _ = ByteString::try_from(&Bytes::from_static(b"nice bytes")).unwrap();
500        assert!(ByteString::try_from(&Bytes::from_static(b"\xc3\x28")).is_err());
501
502        let _ =
503            ByteString::try_from(BytesMut::copy_from_slice(&b"nice bytes"[..])).unwrap();
504        assert!(ByteString::try_from(BytesMut::copy_from_slice(b"\xc3\x28")).is_err());
505    }
506
507    #[test]
508    fn test_serialize() {
509        let s: ByteString = serde_json::from_str(r#""nice bytes""#).unwrap();
510        assert_eq!(s, "nice bytes");
511    }
512
513    #[test]
514    fn test_deserialize() {
515        let s = serde_json::to_string(&ByteString::from_static("nice bytes")).unwrap();
516        assert_eq!(s, r#""nice bytes""#);
517    }
518}
ntex_bytes/string.rs

ntex_bytes/
string.rs
