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ntex_bytes/
bytes.rs

1use std::{cmp, hash, mem, ops};
2
3use crate::{Buf, BytesMut, storage::Storage};
4
5/// A reference counted contiguous slice of memory.
6///
7/// `Bytes` is an efficient container for storing and operating on contiguous
8/// slices of memory. It is intended primarily for use in networking code, but
9/// could have applications elsewhere as well.
10///
11/// `Bytes` values facilitate zero-copy network programming by allowing multiple
12/// `Bytes` objects to point to the same underlying memory. This is managed by
13/// using a reference count to track when the memory is no longer needed and can
14/// be freed.
15///
16/// ```
17/// use ntex_bytes::Bytes;
18///
19/// let mut mem = Bytes::from(&b"Hello world"[..]);
20/// let a = mem.slice(0..5);
21///
22/// assert_eq!(a, b"Hello");
23///
24/// let b = mem.split_to(6);
25///
26/// assert_eq!(mem, b"world");
27/// assert_eq!(b, b"Hello ");
28/// ```
29///
30/// # Memory layout
31///
32/// The `Bytes` struct itself is fairly small, limited to a pointer to the
33/// memory and two `usize` fields used to track information about which segment of
34/// the underlying memory the `Bytes` handle has access to.
35///
36/// The memory layout looks like this:
37///
38/// ```text
39/// +-------+
40/// | Bytes |
41/// +-------+
42///  /      \_____
43/// |              \
44/// v               v
45/// +-----+------------------------------------+
46/// | MD  |         |      Data     |          |
47/// +-----+------------------------------------+
48/// ```
49///
50/// `Bytes` keeps a pointer to the start of the region visible to the handle and
51/// an `offset` that can be used to calculate the beginning of the heap-allocated
52/// buffer. `Bytes` also tracks the length of its view into the memory.
53///
54/// # Sharing
55///
56/// The memory itself is reference counted, and multiple `Bytes` objects may
57/// point to the same region. Each `Bytes` handle points to a section of the
58/// memory region, and `Bytes` handles may or may not have overlapping views
59/// into the memory.
60///
61/// ```text
62///
63///    Arc ptrs                   +---------+
64///    ________________________ / | Bytes 2 |
65///   /                           +---------+
66///  /          +-----------+     |         |
67/// |_________/ |  Bytes 1  |     |         |
68/// |           +-----------+     |         |
69/// |           |           | ___/ data     | tail
70/// |      data |      tail |/              |
71/// v           v           v               v
72/// +-----+---------------------------------+-----+
73/// | MD  |     |           |               |     |
74/// +-----+---------------------------------+-----+
75/// ```
76///
77/// # Mutating
78///
79/// While `Bytes` handles may represent overlapping views of the underlying
80/// memory slice and therefore cannot be mutated, `BytesMut` handles are
81/// guaranteed to be the only handle able to view that slice of memory. As such,
82/// `BytesMut` handles may mutate the underlying memory. Note that holding a
83/// unique view of a region of memory does not mean there are no other `Bytes`
84/// handles with disjoint views of the same underlying allocation.
85///
86/// # Inline bytes
87///
88/// As an optimization, when the slice referenced by a `Bytes` handle is small
89/// enough [^1], the data may be stored inline. In this case, a clone is no longer
90/// “shallow”, and the data will be copied. `BytesMut` does not support data
91/// inlining and always allocates, but during conversion to `Bytes`, data from
92/// `BytesMut` may be inlined.
93///
94/// [^1]: Small enough: 23 bytes on 64 bit systems, 11 on 32 bit systems.
95///
96pub struct Bytes {
97    pub(crate) storage: Storage,
98}
99
100/*
101 *
102 * ===== Bytes =====
103 *
104 */
105
106impl Bytes {
107    /// Creates a new empty `Bytes`.
108    ///
109    /// This will not allocate and the returned `Bytes` handle will be empty.
110    ///
111    /// # Examples
112    ///
113    /// ```
114    /// use ntex_bytes::Bytes;
115    ///
116    /// let b = Bytes::new();
117    /// assert_eq!(&b[..], b"");
118    /// ```
119    #[inline]
120    pub const fn new() -> Bytes {
121        Bytes {
122            storage: Storage::empty(),
123        }
124    }
125
126    /// Creates a new `Bytes` from a static slice.
127    ///
128    /// The returned `Bytes` will point directly to the static slice. There is
129    /// no allocating or copying.
130    ///
131    /// # Examples
132    ///
133    /// ```
134    /// use ntex_bytes::Bytes;
135    ///
136    /// let b = Bytes::from_static(b"hello");
137    /// assert_eq!(&b[..], b"hello");
138    /// ```
139    #[inline]
140    #[must_use]
141    pub const fn from_static(bytes: &'static [u8]) -> Bytes {
142        Bytes {
143            storage: Storage::from_static(bytes),
144        }
145    }
146
147    /// Returns the number of bytes contained in this `Bytes`.
148    ///
149    /// # Examples
150    ///
151    /// ```
152    /// use ntex_bytes::Bytes;
153    ///
154    /// let b = Bytes::from(&b"hello"[..]);
155    /// assert_eq!(b.len(), 5);
156    /// ```
157    #[inline]
158    pub fn len(&self) -> usize {
159        self.storage.len()
160    }
161
162    /// Returns true if the `Bytes` has a length of 0.
163    ///
164    /// # Examples
165    ///
166    /// ```
167    /// use ntex_bytes::Bytes;
168    ///
169    /// let b = Bytes::new();
170    /// assert!(b.is_empty());
171    /// ```
172    #[inline]
173    pub fn is_empty(&self) -> bool {
174        self.storage.is_empty()
175    }
176
177    /// Returns `true` if the bytes are stored inline.
178    ///
179    /// # Examples
180    /// ```
181    /// use ntex_bytes::{Bytes, BytesMut};
182    ///
183    /// assert!(Bytes::from(BytesMut::from(&[0, 0, 0, 0][..])).is_inline());
184    /// assert!(Bytes::from(Vec::with_capacity(4)).is_inline());
185    /// assert!(!Bytes::from(&[0; 1024][..]).is_inline());
186    /// ```
187    pub fn is_inline(&self) -> bool {
188        self.storage.is_inline()
189    }
190
191    /// Creates a `Bytes` value by copying a byte slice.
192    ///
193    /// Data from the slice could be inlined.
194    #[must_use]
195    pub fn copy_from_slice(data: &[u8]) -> Self {
196        Bytes {
197            storage: Storage::from_slice(data),
198        }
199    }
200
201    /// Returns a slice of self for the provided range.
202    ///
203    /// This will increment the reference count for the underlying memory and
204    /// return a new `Bytes` handle set to the slice. A slice that fits inline
205    /// is copied instead.
206    ///
207    /// This operation is `O(1)`.
208    ///
209    /// # Examples
210    ///
211    /// ```
212    /// use ntex_bytes::Bytes;
213    ///
214    /// let a = Bytes::from(b"hello world");
215    /// let b = a.slice(2..5);
216    ///
217    /// assert_eq!(&b[..], b"llo");
218    /// assert_eq!(&b[..=1], b"ll");
219    /// assert_eq!(&b[1..=1], b"l");
220    /// ```
221    ///
222    /// # Panics
223    ///
224    /// Requires that `begin <= end` and `end <= self.len()`, otherwise slicing
225    /// will panic.
226    #[must_use]
227    pub fn slice(&self, range: impl ops::RangeBounds<usize>) -> Bytes {
228        self.slice_checked(range)
229            .expect("Requires that `begin <= end` and `end <= self.len()`")
230    }
231
232    /// Returns a slice of self for the provided range.
233    ///
234    /// Returns `None` unless `begin <= end` and `end <= self.len()`.
235    #[must_use]
236    pub fn slice_checked(&self, range: impl ops::RangeBounds<usize>) -> Option<Bytes> {
237        use std::ops::Bound;
238
239        let len = self.len();
240
241        let begin = match range.start_bound() {
242            Bound::Included(&n) => n,
243            Bound::Excluded(&n) => n.checked_add(1)?,
244            Bound::Unbounded => 0,
245        };
246
247        let end = match range.end_bound() {
248            Bound::Included(&n) => n.checked_add(1)?,
249            Bound::Excluded(&n) => n,
250            Bound::Unbounded => len,
251        };
252
253        if begin <= end && end <= len {
254            Some(Bytes {
255                storage: self.storage.slice(begin, end),
256            })
257        } else {
258            None
259        }
260    }
261
262    /// Returns a slice of self that is equivalent to the given `subset`.
263    ///
264    /// When processing a `Bytes` buffer with other tools, one often gets a
265    /// `&[u8]` which is in fact a slice of the `Bytes`, i.e. a subset of it.
266    /// This function turns that `&[u8]` into another `Bytes`, as if one had
267    /// called `self.slice()` with the offsets that correspond to `subset`.
268    ///
269    /// This operation is `O(1)`.
270    ///
271    /// # Examples
272    ///
273    /// ```
274    /// use ntex_bytes::Bytes;
275    ///
276    /// let bytes = Bytes::from(&b"012345678"[..]);
277    /// let as_slice = bytes.as_ref();
278    /// let subset = &as_slice[2..6];
279    /// let subslice = bytes.slice_ref(&subset);
280    /// assert_eq!(subslice, b"2345");
281    /// ```
282    ///
283    /// # Panics
284    ///
285    /// Requires that the given `subset` slice is in fact contained within the
286    /// `Bytes` buffer; otherwise this function will panic.
287    #[must_use]
288    pub fn slice_ref(&self, subset: &[u8]) -> Bytes {
289        self.slice_ref_checked(subset)
290            .expect("Given `subset` slice is not contained within the `Bytes` buffer")
291    }
292
293    /// Returns a slice of self that is equivalent to the given `subset`.
294    ///
295    /// Returns `None` if `subset` is not contained within the `Bytes` buffer.
296    #[must_use]
297    pub fn slice_ref_checked(&self, subset: &[u8]) -> Option<Bytes> {
298        let bytes_p = self.as_ptr() as usize;
299        let bytes_len = self.len();
300
301        let sub_p = subset.as_ptr() as usize;
302        let sub_len = subset.len();
303
304        if sub_p >= bytes_p && sub_p + sub_len <= bytes_p + bytes_len {
305            let sub_offset = sub_p - bytes_p;
306            Some(self.slice(sub_offset..(sub_offset + sub_len)))
307        } else {
308            None
309        }
310    }
311
312    /// Splits the bytes into two at the given index.
313    ///
314    /// Afterwards `self` contains elements `[0, at)`, and the returned `Bytes`
315    /// contains elements `[at, len)`.
316    ///
317    /// This is an `O(1)` operation that just increases the reference count and
318    /// sets a few indices.
319    ///
320    /// # Examples
321    ///
322    /// ```
323    /// use ntex_bytes::Bytes;
324    ///
325    /// let mut a = Bytes::from(&b"hello world"[..]);
326    /// let b = a.split_off(5);
327    ///
328    /// assert_eq!(a, b"hello");
329    /// assert_eq!(b, b" world");
330    /// ```
331    ///
332    /// # Panics
333    ///
334    /// Panics if `at > self.len()`.
335    #[must_use]
336    #[inline]
337    pub fn split_off(&mut self, at: usize) -> Bytes {
338        self.split_off_checked(at)
339            .expect("at value must be <= self.len()`")
340    }
341
342    /// Splits the bytes into two at the given index.
343    ///
344    /// Returns `None` if `at > self.len()`.
345    #[must_use]
346    #[inline]
347    pub fn split_off_checked(&mut self, at: usize) -> Option<Bytes> {
348        if at <= self.len() {
349            if at == self.len() {
350                Some(Bytes::new())
351            } else if at == 0 {
352                Some(mem::take(self))
353            } else {
354                Some(Bytes {
355                    storage: self.storage.split_off(at, true),
356                })
357            }
358        } else {
359            None
360        }
361    }
362
363    /// Splits the bytes into two at the given index.
364    ///
365    /// Afterwards `self` contains elements `[at, len)`, and the returned
366    /// `Bytes` contains elements `[0, at)`.
367    ///
368    /// This is an `O(1)` operation that just increases the reference count and
369    /// sets a few indices.
370    ///
371    /// # Examples
372    ///
373    /// ```
374    /// use ntex_bytes::Bytes;
375    ///
376    /// let mut a = Bytes::from(&b"hello world"[..]);
377    /// let b = a.split_to(5);
378    ///
379    /// assert_eq!(a, b" world");
380    /// assert_eq!(b, b"hello");
381    /// ```
382    ///
383    /// # Panics
384    ///
385    /// Panics if `at > len`.
386    #[must_use]
387    #[inline]
388    pub fn split_to(&mut self, at: usize) -> Bytes {
389        self.split_to_checked(at)
390            .expect("at value must be <= self.len()`")
391    }
392
393    /// Splits the bytes into two at the given index.
394    ///
395    /// Returns `None` if `at > len`.
396    #[must_use]
397    #[inline]
398    pub fn split_to_checked(&mut self, at: usize) -> Option<Bytes> {
399        if at <= self.len() {
400            if at == self.len() {
401                Some(mem::take(self))
402            } else if at == 0 {
403                Some(Bytes::new())
404            } else {
405                Some(Bytes {
406                    storage: self.storage.split_to(at),
407                })
408            }
409        } else {
410            None
411        }
412    }
413
414    /// Advance the internal cursor.
415    ///
416    /// Afterwards `self` contains elements `[cnt, len)`.
417    /// This is an `O(1)` operation.
418    ///
419    /// # Examples
420    ///
421    /// ```
422    /// use ntex_bytes::Bytes;
423    ///
424    /// let mut a = Bytes::copy_from_slice(&b"hello world"[..]);
425    /// a.advance_to(5);
426    ///
427    /// assert_eq!(&a[..], b" world");
428    /// ```
429    ///
430    /// # Panics
431    ///
432    /// Panics if `cnt > len`.
433    #[inline]
434    pub fn advance_to(&mut self, cnt: usize) {
435        unsafe {
436            self.storage.set_start(cnt);
437        }
438    }
439
440    /// Shortens the buffer, keeping the first `len` bytes and dropping the
441    /// rest.
442    ///
443    /// If `len` is greater than the buffer's current length, this has no
444    /// effect. The data may be inlined if it fits.
445    ///
446    /// The [`split_off`] method can emulate `truncate`, but this causes the
447    /// excess bytes to be returned instead of dropped.
448    ///
449    /// # Examples
450    ///
451    /// ```
452    /// use ntex_bytes::Bytes;
453    ///
454    /// let mut buf = Bytes::from(&b"hello world"[..]);
455    /// buf.truncate(5);
456    /// assert_eq!(buf, b"hello"[..]);
457    /// ```
458    ///
459    /// [`split_off`]: #method.split_off
460    #[inline]
461    pub fn truncate(&mut self, len: usize) {
462        self.storage.truncate(len);
463    }
464
465    /// Compacts the underlying storage to this value's current byte range.
466    ///
467    /// This can reduce retained capacity when this value is a small view into a
468    /// larger allocation, anywhere within the allocation. The data is copied if
469    /// the allocation is larger than the view by at least 64 bytes, views up to
470    /// the inline capacity are always inlined. The visible bytes are unchanged.
471    ///
472    /// # Examples
473    ///
474    /// ```
475    /// use ntex_bytes::Bytes;
476    ///
477    /// let mut buf = Bytes::from(&b"hello world"[..]);
478    /// buf.trimdown();
479    /// assert_eq!(buf, b"hello world"[..]);
480    /// ```
481    #[inline]
482    pub fn trimdown(&mut self) {
483        self.storage.trimdown();
484    }
485
486    /// Clears the buffer, removing all data.
487    ///
488    /// # Examples
489    ///
490    /// ```
491    /// use ntex_bytes::Bytes;
492    ///
493    /// let mut buf = Bytes::from(&b"hello world"[..]);
494    /// buf.clear();
495    /// assert!(buf.is_empty());
496    /// ```
497    #[inline]
498    pub fn clear(&mut self) {
499        self.storage = Storage::empty();
500    }
501
502    /// Returns an iterator over the bytes contained by the buffer.
503    ///
504    /// # Examples
505    ///
506    /// ```
507    /// use ntex_bytes::{Buf, Bytes};
508    ///
509    /// let buf = Bytes::from(&b"abc"[..]);
510    /// let mut iter = buf.iter();
511    ///
512    /// assert_eq!(iter.next().map(|b| *b), Some(b'a'));
513    /// assert_eq!(iter.next().map(|b| *b), Some(b'b'));
514    /// assert_eq!(iter.next().map(|b| *b), Some(b'c'));
515    /// assert_eq!(iter.next(), None);
516    /// ```
517    pub fn iter(&'_ self) -> std::slice::Iter<'_, u8> {
518        self.chunk().iter()
519    }
520
521    #[inline]
522    #[doc(hidden)]
523    pub fn info(&self) -> crate::info::Info {
524        self.storage.info()
525    }
526}
527
528impl_buf!(Bytes {
529    #[inline]
530    fn get_u8(&mut self) -> u8 {
531        self.storage.get_u8()
532    }
533});
534
535impl_slice_traits!(Bytes);
536
537impl Clone for Bytes {
538    #[inline]
539    fn clone(&self) -> Bytes {
540        Bytes {
541            storage: self.storage.clone(),
542        }
543    }
544}
545
546impl From<&Bytes> for Bytes {
547    fn from(src: &Bytes) -> Bytes {
548        src.clone()
549    }
550}
551
552impl From<crate::ByteString> for Bytes {
553    fn from(src: crate::ByteString) -> Bytes {
554        src.into_bytes()
555    }
556}
557
558impl From<&crate::ByteString> for Bytes {
559    fn from(src: &crate::ByteString) -> Bytes {
560        src.clone().into_bytes()
561    }
562}
563
564impl From<Vec<u8>> for Bytes {
565    /// Convert a `Vec` into a `Bytes`
566    fn from(src: Vec<u8>) -> Bytes {
567        Bytes {
568            storage: Storage::from_slice(&src),
569        }
570    }
571}
572
573impl From<String> for Bytes {
574    fn from(src: String) -> Bytes {
575        Bytes {
576            storage: Storage::from_slice(src.as_bytes()),
577        }
578    }
579}
580
581impl From<&'static [u8]> for Bytes {
582    fn from(src: &'static [u8]) -> Bytes {
583        Bytes::from_static(src)
584    }
585}
586
587impl From<&'static str> for Bytes {
588    fn from(src: &'static str) -> Bytes {
589        Bytes::from_static(src.as_bytes())
590    }
591}
592
593impl<'a, const N: usize> From<&'a [u8; N]> for Bytes {
594    fn from(src: &'a [u8; N]) -> Bytes {
595        Bytes::copy_from_slice(src)
596    }
597}
598
599impl FromIterator<u8> for Bytes {
600    fn from_iter<T: IntoIterator<Item = u8>>(into_iter: T) -> Self {
601        BytesMut::from_iter(into_iter).freeze()
602    }
603}
604
605impl<'a> FromIterator<&'a u8> for Bytes {
606    fn from_iter<T: IntoIterator<Item = &'a u8>>(into_iter: T) -> Self {
607        BytesMut::from_iter(into_iter).freeze()
608    }
609}
610
611impl Eq for Bytes {}
612
613impl PartialEq for Bytes {
614    fn eq(&self, other: &Bytes) -> bool {
615        self.storage.as_ref() == other.storage.as_ref()
616    }
617}
618
619impl PartialOrd for Bytes {
620    fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
621        Some(self.cmp(other))
622    }
623}
624
625impl Ord for Bytes {
626    fn cmp(&self, other: &Bytes) -> cmp::Ordering {
627        self.storage.as_ref().cmp(other.storage.as_ref())
628    }
629}
630
631impl_read!(Bytes);
632
633impl hash::Hash for Bytes {
634    fn hash<H>(&self, state: &mut H)
635    where
636        H: hash::Hasher,
637    {
638        let s: &[u8] = self.as_ref();
639        s.hash(state);
640    }
641}
642
643impl_partial_eq!(Bytes);
644impl_partial_ord!(Bytes);
645
646#[cfg(test)]
647#[allow(unused_must_use)]
648mod tests {
649    use std::collections::HashMap;
650
651    use super::*;
652    use crate::{BufMut, storage::INLINE_CAP};
653
654    const LONG: &[u8] = b"mary had a1 little la2mb, little lamb, little lamb, little lamb, little lamb, little lamb \
655        mary had a little lamb, little lamb, little lamb, little lamb, little lamb, little lamb \
656        mary had a little lamb, little lamb, little lamb, little lamb, little lamb, little lamb \0";
657
658    #[test]
659    #[allow(clippy::op_ref, clippy::cmp_owned)]
660    fn partial_ord_reverse() {
661        let b = Bytes::from_static(b"b");
662        assert!(b"a"[..] < b);
663        assert!(*b"a" < b);
664        assert!(*"a" < b);
665        assert!(b"a".to_vec() < b);
666        assert!(String::from("a") < b);
667        assert!(&b"a"[..] < b);
668        assert!("a" < b);
669        assert!(b"c"[..] > b);
670        assert!("c" > b);
671        assert_eq!(b"b"[..].partial_cmp(&b), Some(cmp::Ordering::Equal));
672    }
673
674    #[test]
675    fn slice_checked_max_bounds() {
676        use std::ops::Bound;
677
678        let b = Bytes::from(LONG.to_vec());
679        assert!(b.slice_checked(..=usize::MAX).is_none());
680        assert!(
681            b.slice_checked((Bound::Excluded(usize::MAX), Bound::Unbounded))
682                .is_none()
683        );
684    }
685
686    #[test]
687    #[allow(
688        clippy::op_ref,
689        clippy::len_zero,
690        clippy::nonminimal_bool,
691        clippy::unnecessary_fallible_conversions
692    )]
693    fn bytes() {
694        let mut b = Bytes::from(LONG.to_vec());
695        b.advance_to(10);
696        assert_eq!(&b, &LONG[10..]);
697        b.advance_to(10);
698        assert_eq!(&b[..], &LONG[20..]);
699        assert_eq!(&b, &LONG[20..]);
700        b.clear();
701        assert!(b.is_inline());
702        assert!(b.is_empty());
703        assert_eq!(b.len(), 0);
704
705        let mut b = Bytes::from(LONG);
706        b.advance_to(10);
707        assert_eq!(&b, &LONG[10..]);
708        b.advance_to(10);
709        assert_eq!(&b[..], &LONG[20..]);
710        assert_eq!(&b, &LONG[20..]);
711        b.clear();
712        assert!(b.is_empty());
713        assert_eq!(b.len(), 0);
714
715        let mut b = Bytes::from(LONG);
716        b.split_off(10);
717        assert_eq!(&b, &LONG[..10]);
718        b.advance_to(5);
719        assert_eq!(&b, &LONG[5..10]);
720
721        let mut b = Bytes::copy_from_slice(&LONG[..INLINE_CAP]);
722        assert!(b.is_inline());
723        b.split_off(10);
724        assert_eq!(&b, &LONG[..10]);
725        b.advance_to(1);
726        assert_eq!(&b, &LONG[1..10]);
727
728        let mut b = Bytes::from(b"123");
729        assert!(&b"12"[..] < &b);
730        assert_eq!("123", &b);
731        assert!("12" < &b);
732        assert!("12" < b);
733        assert_eq!(b.get_u8(), b'1');
734        assert_eq!("23", &b);
735
736        let mut b = Bytes::from(&Bytes::from(LONG));
737        assert_eq!(b, LONG);
738        assert_eq!(b.get_u8(), LONG[0]);
739        assert_eq!(b.get_u8(), LONG[1]);
740        assert_eq!(b.len(), LONG.len() - 2);
741
742        let b = Bytes::from(BytesMut::from(LONG));
743        assert_eq!(b, LONG);
744
745        let mut b: Bytes = BytesMut::try_from(b).unwrap().freeze();
746        assert_eq!(b, LONG);
747        assert!(!(b > b));
748        assert_eq!(<Bytes as Buf>::remaining(&b), LONG.len());
749        assert_eq!(<Bytes as Buf>::chunk(&b), LONG);
750        <Bytes as Buf>::advance(&mut b, 10);
751        assert_eq!(Buf::chunk(&b), &LONG[10..]);
752        <Bytes as Buf>::advance(&mut b, 10);
753        assert_eq!(Buf::chunk(&b), &LONG[20..]);
754
755        let mut h: HashMap<Bytes, usize> = HashMap::default();
756        h.insert(b.clone(), 1);
757        assert_eq!(h.get(&b), Some(&1));
758
759        let mut b = BytesMut::try_from(LONG).unwrap();
760        assert_eq!(b, LONG);
761        assert_eq!(<BytesMut as Buf>::remaining(&b), LONG.len());
762        assert_eq!(<BytesMut as BufMut>::remaining_mut(&b), 0);
763        assert_eq!(<BytesMut as Buf>::chunk(&b), LONG);
764        <BytesMut as Buf>::advance(&mut b, 10);
765        assert_eq!(<BytesMut as Buf>::chunk(&b), &LONG[10..]);
766
767        let mut b = BytesMut::with_capacity(12);
768        <BytesMut as BufMut>::put_i8(&mut b, 1);
769        assert_eq!(b, b"\x01".as_ref());
770        <BytesMut as BufMut>::put_u8(&mut b, 2);
771        assert_eq!(b, b"\x01\x02".as_ref());
772        <BytesMut as BufMut>::put_slice(&mut b, b"12345");
773        assert_eq!(b, b"\x01\x0212345".as_ref());
774        <BytesMut as BufMut>::chunk_mut(&mut b).write_byte(0, b'1');
775        unsafe { <BytesMut as BufMut>::advance_mut(&mut b, 1) };
776        assert_eq!(b, b"\x01\x02123451".as_ref());
777
778        let mut iter = Bytes::from(LONG.to_vec()).into_iter();
779        assert_eq!(iter.next(), Some(LONG[0]));
780        assert_eq!(iter.next(), Some(LONG[1]));
781        assert_eq!(iter.next(), Some(LONG[2]));
782        assert_eq!(iter.next(), Some(LONG[3]));
783        assert_eq!(iter.get_ref(), &LONG[4..]);
784        assert_eq!(iter.get_mut(), &LONG[4..]);
785        let b = iter.into_inner();
786        assert_eq!(b, &LONG[4..]);
787
788        let mut b = Bytes::copy_from_slice(b"123");
789        assert!(b.is_inline());
790        assert_eq!(b.storage.capacity(), INLINE_CAP);
791        b.truncate(2);
792        assert_eq!(b, *b"12");
793        assert_eq!(bytes::buf::Buf::get_u8(&mut b), 49);
794        assert_eq!(b.len(), 1);
795    }
796
797    #[test]
798    fn bytes_read() {
799        use std::io::Read;
800
801        let mut b = Bytes::copy_from_slice(b"123");
802
803        let mut buf = [0; 10];
804        assert_eq!(b.read(&mut buf).unwrap(), 3);
805        assert_eq!(b.len(), 0);
806        assert_eq!(buf, [49, 50, 51, 0, 0, 0, 0, 0, 0, 0]);
807    }
808
809    #[test]
810    fn from_byte_string() {
811        let s = crate::ByteString::from_static("string");
812        assert_eq!(Bytes::from(&s), "string");
813        assert_eq!(Bytes::from(s), "string");
814    }
815}