Struct bytes::Bytes

pub struct Bytes { /* fields omitted */ }

A reference counted slice of bytes.

A Bytes is an immutable sequence of bytes. Given that it is guaranteed to be immutable, Bytes is Sync, Clone is shallow (ref count increment), and all operations only update views into the underlying data without requiring any copies.

Methods

impl Bytes

fn from_slice<T: AsRef<[u8]>>(bytes: T) -> Bytes

Creates a new Bytes and copy the given slice into it.

fn len(&self) -> usize

Returns the number of bytes contained in this Bytes.

fn is_empty(&self) -> bool

Returns true if the value contains no bytes

fn as_slice(&self) -> &[u8]

Returns the inner contents of this Bytes as a slice.

fn slice(&self, start: usize, end: usize) -> Bytes

Extracts a new Bytes referencing the bytes from range [start, end).

fn slice_from(&self, start: usize) -> Bytes

Extracts a new Bytes referencing the bytes from range [start, len).

fn slice_to(&self, end: usize) -> Bytes

Extracts a new Bytes referencing the bytes from range [0, end).

fn split_off(&mut self, at: usize) -> Bytes

Splits the bytes into two at the given index.

Afterwards self contains elements [0, at), and the returned Bytes contains elements [at, len).

This is an O(1) operation that just increases the reference count and sets a few indexes.

Panics

Panics if at > len

fn drain_to(&mut self, at: usize) -> Bytes

Splits the buffer into two at the given index.

Afterwards self contains elements [at, len), and the returned Bytes contains elements [0, at).

This is an O(1) operation that just increases the reference count and sets a few indexes.

Panics

Panics if at > len

fn try_mut(self) -> Result<BytesMut, Bytes>

Attempt to convert into a BytesMut handle.

This will only succeed if there are no other outstanding references to the underlying chunk of memory.

fn into_mut(self) -> BytesMut

Consumes handle, returning a new mutable handle

The function attempts to avoid copying, however if it is unable to obtain a unique reference to the underlying data, a new buffer is allocated and the data is copied to it.

Methods from Deref<Target=[u8]>

fn len(&self) -> usize

Returns the number of elements in the slice.

Example

let a = [1, 2, 3];
assert_eq!(a.len(), 3);

fn is_empty(&self) -> bool

Returns true if the slice has a length of 0.

Example

let a = [1, 2, 3];
assert!(!a.is_empty());

fn first(&self) -> Option<&T>

Returns the first element of a slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&10), v.first());

let w: &[i32] = &[];
assert_eq!(None, w.first());

fn split_first(&self) -> Option<(&T, &[T])>

Returns the first and all the rest of the elements of a slice.

Examples

let x = &[0, 1, 2];

if let Some((first, elements)) = x.split_first() {
    assert_eq!(first, &0);
    assert_eq!(elements, &[1, 2]);
}

fn split_last(&self) -> Option<(&T, &[T])>

Returns the last and all the rest of the elements of a slice.

Examples

let x = &[0, 1, 2];

if let Some((last, elements)) = x.split_last() {
    assert_eq!(last, &2);
    assert_eq!(elements, &[0, 1]);
}

fn last(&self) -> Option<&T>

Returns the last element of a slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&30), v.last());

let w: &[i32] = &[];
assert_eq!(None, w.last());

fn get(&self, index: usize) -> Option<&T>

Returns the element of a slice at the given index, or None if the index is out of bounds.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&40), v.get(1));
assert_eq!(None, v.get(3));

unsafe fn get_unchecked(&self, index: usize) -> &T

Returns a pointer to the element at the given index, without doing bounds checking. So use it very carefully!

Examples

let x = &[1, 2, 4];

unsafe {
    assert_eq!(x.get_unchecked(1), &2);
}

fn as_ptr(&self) -> *const T

Returns an raw pointer to the slice's buffer.

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Examples

let x = &[1, 2, 4];
let x_ptr = x.as_ptr();

unsafe {
    for i in 0..x.len() {
        assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize));
    }
}

fn iter(&self) -> Iter<T>

Returns an iterator over the slice.

Examples

let x = &[1, 2, 4];
let mut iterator = x.iter();

assert_eq!(iterator.next(), Some(&1));
assert_eq!(iterator.next(), Some(&2));
assert_eq!(iterator.next(), Some(&4));
assert_eq!(iterator.next(), None);

fn windows(&self, size: usize) -> Windows<T>

Returns an iterator over all contiguous windows of length size. The windows overlap. If the slice is shorter than size, the iterator returns no values.

Panics

Panics if size is 0.

Example

let slice = ['r', 'u', 's', 't'];
let mut iter = slice.windows(2);
assert_eq!(iter.next().unwrap(), &['r', 'u']);
assert_eq!(iter.next().unwrap(), &['u', 's']);
assert_eq!(iter.next().unwrap(), &['s', 't']);
assert!(iter.next().is_none());

If the slice is shorter than size:

let slice = ['f', 'o', 'o'];
let mut iter = slice.windows(4);
assert!(iter.next().is_none());

fn chunks(&self, size: usize) -> Chunks<T>

Returns an iterator over size elements of the slice at a time. The chunks are slices and do not overlap. If size does not divide the length of the slice, then the last chunk will not have length size.

Panics

Panics if size is 0.

Example

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert_eq!(iter.next().unwrap(), &['m']);
assert!(iter.next().is_none());

fn split_at(&self, mid: usize) -> (&[T], &[T])

Divides one slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics

Panics if mid > len.

Examples

let v = [10, 40, 30, 20, 50];
let (v1, v2) = v.split_at(2);
assert_eq!([10, 40], v1);
assert_eq!([30, 20, 50], v2);

fn split<F>(&self, pred: F) -> Split<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred. The matched element is not contained in the subslices.

Examples

let slice = [10, 40, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:

let slice = [10, 40, 33];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[]);
assert!(iter.next().is_none());

If two matched elements are directly adjacent, an empty slice will be present between them:

let slice = [10, 6, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10]);
assert_eq!(iter.next().unwrap(), &[]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred, limited to returning at most n items. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once by numbers divisible by 3 (i.e. [10, 40], [20, 60, 50]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.splitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred limited to returning at most n items. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once, starting from the end, by numbers divisible by 3 (i.e. [50], [10, 40, 30, 20]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.rsplitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

fn contains(&self, x: &T) -> bool where T: PartialEq<T>

Returns true if the slice contains an element with the given value.

Examples

let v = [10, 40, 30];
assert!(v.contains(&30));
assert!(!v.contains(&50));

fn starts_with(&self, needle: &[T]) -> bool where T: PartialEq<T>

Returns true if needle is a prefix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.starts_with(&[10]));
assert!(v.starts_with(&[10, 40]));
assert!(!v.starts_with(&[50]));
assert!(!v.starts_with(&[10, 50]));

fn ends_with(&self, needle: &[T]) -> bool where T: PartialEq<T>

Returns true if needle is a suffix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.ends_with(&[30]));
assert!(v.ends_with(&[40, 30]));
assert!(!v.ends_with(&[50]));
assert!(!v.ends_with(&[50, 30]));

fn binary_search(&self, x: &T) -> Result<usize, usize> where T: Ord

Binary search a sorted slice for a given element.

If the value is found then Ok is returned, containing the index of the matching element; if the value is not found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Example

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

assert_eq!(s.binary_search(&13),  Ok(9));
assert_eq!(s.binary_search(&4),   Err(7));
assert_eq!(s.binary_search(&100), Err(13));
let r = s.binary_search(&1);
assert!(match r { Ok(1...4) => true, _ => false, });

fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where F: FnMut(&'a T) -> Ordering

Binary search a sorted slice with a comparator function.

The comparator function should implement an order consistent with the sort order of the underlying slice, returning an order code that indicates whether its argument is Less, Equal or Greater the desired target.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Example

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

let seek = 13;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9));
let seek = 4;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7));
let seek = 100;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13));
let seek = 1;
let r = s.binary_search_by(|probe| probe.cmp(&seek));
assert!(match r { Ok(1...4) => true, _ => false, });

fn binary_search_by_key<'a, B, F>(&'a self, b: &B, f: F) -> Result<usize, usize> where B: Ord, F: FnMut(&'a T) -> B

Binary search a sorted slice with a key extraction function.

Assumes that the slice is sorted by the key, for instance with sort_by_key using the same key extraction function.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements in a slice of pairs sorted by their second elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1),
         (1, 2), (2, 3), (4, 5), (5, 8), (3, 13),
         (1, 21), (2, 34), (4, 55)];

assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b),  Ok(9));
assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b),   Err(7));
assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13));
let r = s.binary_search_by_key(&1, |&(a,b)| b);
assert!(match r { Ok(1...4) => true, _ => false, });

fn to_vec(&self) -> Vec<T> where T: Clone

Copies self into a new Vec.

Examples

let s = [10, 40, 30];
let x = s.to_vec();
// Here, `s` and `x` can be modified independently.

fn into_vec(self: Box<[T]>) -> Vec<T>

Converts self into a vector without clones or allocation.

Examples

let s: Box<[i32]> = Box::new([10, 40, 30]);
let x = s.into_vec();
// `s` cannot be used anymore because it has been converted into `x`.

assert_eq!(x, vec![10, 40, 30]);

Trait Implementations

impl From<ByteBuf> for Bytes

fn from(src: ByteBuf) -> Bytes

Performs the conversion.

impl Source for Bytes

fn source<B: BufMut>(self, buf: &mut B)

Copy data from self into destination buffer

impl<'a> Source for &'a Bytes

fn source<B: BufMut>(self, buf: &mut B)

Copy data from self into destination buffer

impl Eq for Bytes

impl IntoBuf for Bytes

type Buf = SliceBuf<Self>

The Buf type that self is being converted into

fn into_buf(self) -> Self::Buf

Creates a Buf from a value.

impl<'a> IntoBuf for &'a Bytes

type Buf = SliceBuf<Self>

The Buf type that self is being converted into

fn into_buf(self) -> Self::Buf

Creates a Buf from a value.

impl Clone for Bytes

fn clone(&self) -> Bytes

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl AsRef<[u8]> for Bytes

fn as_ref(&self) -> &[u8]

Performs the conversion.

impl Deref for Bytes

type Target = [u8]

The resulting type after dereferencing

fn deref(&self) -> &[u8]

The method called to dereference a value

impl From<BytesMut> for Bytes

fn from(src: BytesMut) -> Bytes

Performs the conversion.

impl From<Vec<u8>> for Bytes

fn from(src: Vec<u8>) -> Bytes

Performs the conversion.

impl<'a> From<&'a [u8]> for Bytes

fn from(src: &'a [u8]) -> Bytes

Performs the conversion.

impl PartialEq for Bytes

fn eq(&self, other: &Bytes) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Debug for Bytes

fn fmt(&self, fmt: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Sync for Bytes

impl PartialEq<[u8]> for Bytes

fn eq(&self, other: &[u8]) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Vec<u8>> for Bytes

fn eq(&self, other: &Vec<u8>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'a, T: ?Sized> PartialEq<&'a T> for Bytes where Bytes: PartialEq<T>

fn eq(&self, other: &&'a T) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.