Struct zerovec::ZeroSlice

#[repr(transparent)]
pub struct ZeroSlice<T: AsULE>(_);

A zero-copy “slice”, i.e. the zero-copy version of [T]. This behaves similarly to ZeroVec<T>, however ZeroVec<T> is allowed to contain owned data and as such is ideal for deserialization since most human readable serialization formats cannot unconditionally deserialize zero-copy.

This type can be used inside VarZeroVec<T>: This essentially allows for the construction of zero-copy types isomorphic to Vec<Vec<T>> by instead using VarZeroVec<ZeroSlice<T>>. See the VarZeroVec docs for an example.

Implementations

impl<T> ZeroSlice<T> where
    T: AsULE, 

pub fn as_zerovec(&self) -> ZeroVec<'_, T>

Get this ZeroSlice as a borrowed ZeroVec

ZeroSlice does not have most of the methods that ZeroVec does, so it is recommended to convert it to a ZeroVec before doing anything.

pub fn from_ule_slice(slice: &[T::ULE]) -> &Self

Construct a &ZeroSlice<T> from a slice of ULEs

pub fn from_boxed_slice(slice: Box<[T::ULE]>) -> Box<Self>

Construct a Box<ZeroSlice<T>> from a boxed slice of ULEs

pub fn as_bytes(&self) -> &[u8]

Returns this slice as its underlying &[u8] byte buffer representation.

Useful for serialization.

Example

use zerovec::ZeroVec;

// The little-endian bytes correspond to the numbers on the following line.
let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let nums: &[u16] = &[211, 281, 421, 461];

let zerovec = ZeroVec::alloc_from_slice(nums);

assert_eq!(bytes, zerovec.as_bytes());

pub fn as_ule_slice(&self) -> &[T::ULE]

Dereferences this slice as &[T::ULE].

pub fn len(&self) -> usize

Returns the number of elements in this slice.

Example

use zerovec::ZeroVec;
use zerovec::ule::AsULE;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");

assert_eq!(4, zerovec.len());
assert_eq!(
    bytes.len(),
    zerovec.len() * std::mem::size_of::<<u16 as AsULE>::ULE>()
);

pub fn is_empty(&self) -> bool

Returns whether this slice is empty.

Example

use zerovec::ZeroVec;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");
assert!(!zerovec.is_empty());

let emptyvec: ZeroVec<u16> = ZeroVec::parse_byte_slice(&[]).expect("infallible");
assert!(emptyvec.is_empty());

impl<T> ZeroSlice<T> where
    T: AsULE, 

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

Gets the element at the specified index. Returns None if out of range.

Example

use zerovec::ZeroVec;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");

assert_eq!(zerovec.get(2), Some(421));
assert_eq!(zerovec.get(4), None);

pub fn get_subslice(&self, range: Range<usize>) -> Option<&ZeroSlice<T>>

Gets a subslice of elements within a certain range. Returns None if the range is out of bounds of this ZeroSlice.

Example

use zerovec::ZeroVec;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");

assert_eq!(
    zerovec.get_subslice(1..3),
    Some(&*ZeroVec::from_slice(&[0x0119, 0x01A5]))
);
assert_eq!(zerovec.get_subslice(3..5), None);

pub fn get_ule_ref(&self, index: usize) -> Option<&T::ULE>

Get a borrowed reference to the underlying ULE type at a specified index.

Prefer Self::get() over this method where possible since working directly with ULE types is less ergonomic

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

Gets the first element. Returns None if empty.

Example

use zerovec::ZeroVec;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");

assert_eq!(zerovec.first(), Some(211));

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

Gets the last element. Returns None if empty.

Example

use zerovec::ZeroVec;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");

assert_eq!(zerovec.last(), Some(461));

pub fn iter(&self) -> impl Iterator<Item = T> + '_

Gets an iterator over the elements.

Example

use zerovec::ZeroVec;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");
let mut it = zerovec.iter();

assert_eq!(it.next(), Some(211));
assert_eq!(it.next(), Some(281));
assert_eq!(it.next(), Some(421));
assert_eq!(it.next(), Some(461));
assert_eq!(it.next(), None);

impl<T> ZeroSlice<T> where
    T: AsULE + Ord, 

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

Binary searches a sorted ZeroVec<T> for the given element. For more information, see the primitive function binary_search.

Example

use zerovec::ZeroVec;

let bytes: &[u8] = &[0xD3, 0x00, 0x19, 0x01, 0xA5, 0x01, 0xCD, 0x01];
let zerovec: ZeroVec<u16> = ZeroVec::parse_byte_slice(bytes).expect("infallible");

assert_eq!(zerovec.binary_search(&281), Ok(1));
assert_eq!(zerovec.binary_search(&282), Err(2));

Trait Implementations

impl<T: AsULE> AsRef<ZeroSlice<T>> for Vec<T::ULE>

fn as_ref(&self) -> &ZeroSlice<T>

Performs the conversion.

impl<T: AsULE> AsRef<ZeroSlice<T>> for &[T::ULE]

fn as_ref(&self) -> &ZeroSlice<T>

Performs the conversion.

impl<'a, T: AsULE> AsRef<ZeroSlice<T>> for ZeroVec<'a, T>

fn as_ref(&self) -> &ZeroSlice<T>

Performs the conversion.

impl<'a, T> BorrowedZeroVecLike<'a, T> for &'a ZeroSlice<T> where
    T: AsULE + Ord + Copy, 

fn zvl_get_borrowed(&self, index: usize) -> Option<&'a T::ULE>

Get element at index, with a longer lifetime

impl<T> Debug for ZeroSlice<T> where
    T: AsULE + Debug, 

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Default for &ZeroSlice<T> where
    T: AsULE, 

fn default() -> Self

Returns the “default value” for a type.

impl<T> EncodeAsVarULE<ZeroSlice<T>> for &[T] where
    T: AsULE + 'static, 

fn encode_var_ule_as_slices<R>(&self, _: impl FnOnce(&[&[u8]]) -> R) -> R

Calls cb with a piecewise list of byte slices that when concatenated produce the memory pattern of the corresponding instance of T.

fn encode_var_ule_len(&self) -> usize

Return the length, in bytes, of the corresponding VarULE type

fn encode_var_ule_write(&self, dst: &mut [u8])

Write the corresponding VarULE type to the dst buffer. dst should be the size of Self::encode_var_ule_len()

impl<T> EncodeAsVarULE<ZeroSlice<T>> for Vec<T> where
    T: AsULE + 'static, 

fn encode_var_ule_as_slices<R>(&self, _: impl FnOnce(&[&[u8]]) -> R) -> R

Calls cb with a piecewise list of byte slices that when concatenated produce the memory pattern of the corresponding instance of T.

fn encode_var_ule_len(&self) -> usize

Return the length, in bytes, of the corresponding VarULE type

fn encode_var_ule_write(&self, dst: &mut [u8])

Write the corresponding VarULE type to the dst buffer. dst should be the size of Self::encode_var_ule_len()

impl<T> EncodeAsVarULE<ZeroSlice<T>> for ZeroVec<'_, T> where
    T: AsULE + 'static, 

fn encode_var_ule_as_slices<R>(&self, _: impl FnOnce(&[&[u8]]) -> R) -> R

Calls cb with a piecewise list of byte slices that when concatenated produce the memory pattern of the corresponding instance of T.

fn encode_var_ule_len(&self) -> usize

Return the length, in bytes, of the corresponding VarULE type

fn encode_var_ule_write(&self, dst: &mut [u8])

Write the corresponding VarULE type to the dst buffer. dst should be the size of Self::encode_var_ule_len()

impl<T: AsULE + Ord> Ord for ZeroSlice<T>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<T> PartialEq<[T]> for ZeroSlice<T> where
    T: AsULE + PartialEq, 

fn eq(&self, other: &[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 !=.

impl<T> PartialEq<ZeroSlice<T>> for ZeroSlice<T> where
    T: AsULE + PartialEq, 

fn eq(&self, other: &ZeroSlice<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 !=.

impl<'a, T> PartialEq<ZeroSlice<T>> for ZeroVec<'a, T> where
    T: AsULE + PartialEq, 

fn eq(&self, other: &ZeroSlice<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 !=.

impl<'a, T> PartialEq<ZeroVec<'a, T>> for ZeroSlice<T> where
    T: AsULE + PartialEq, 

fn eq(&self, other: &ZeroVec<'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 !=.

impl<'a, T: AsULE + PartialOrd> PartialOrd<ZeroSlice<T>> for ZeroSlice<T>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Serialize for ZeroSlice<T> where
    T: Serialize + AsULE, 

This impl can be made available by enabling the optional serde feature of the zerovec crate

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl<T: AsULE + 'static> VarULE for ZeroSlice<T>

fn validate_byte_slice(bytes: &[u8]) -> Result<(), ZeroVecError>

Validates a byte slice, &[u8].

unsafe fn from_byte_slice_unchecked(bytes: &[u8]) -> &Self

Takes a byte slice, &[u8], and return it as &Self with the same lifetime, assuming that this byte slice has previously been run through Self::parse_byte_slice() with success.

fn parse_byte_slice(bytes: &[u8]) -> Result<&Self, ZeroVecError>

Parses a byte slice, &[u8], and return it as &Self with the same lifetime.

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

Given &Self, returns a &[u8] with the same lifetime.

fn to_boxed(&self) -> Box<Self>

Allocate on the heap as a Box<T>

impl<'a, T: AsULE + 'static + Ord> ZeroMapKV<'a> for ZeroSlice<T>

type Container = VarZeroVec<'a, ZeroSlice<T>>

The container that can be used with this type: ZeroVec or VarZeroVec.

type GetType = ZeroSlice<T>

The type produced by Container::get()

type OwnedType = Box<ZeroSlice<T>>

The type produced by Container::replace() and Container::remove(), also used during deserialization. If Self is human readable serialized, deserializing to Self::OwnedType should produce the same value once passed through Self::owned_as_self()

impl<'a, T> ZeroVecLike<'a, T> for &'a ZeroSlice<T> where
    T: AsULE + Ord + Copy, 

type GetType = T::ULE

The type returned by Self::get()

type BorrowedVariant = &'a ZeroSlice<T>

A fully borrowed version of this

fn zvl_new() -> Self

Create a new, empty vector

fn zvl_binary_search(&self, k: &T) -> Result<usize, usize>

Search for a key in a sorted vector, returns Ok(index) if found, returns Err(insert_index) if not found, where insert_index is the index where it should be inserted to maintain sort order.

fn zvl_binary_search_in_range(
    &self,
    k: &T,
    range: Range<usize>
) -> Option<Result<usize, usize>>

Search for a key within a certain range in a sorted vector. Returns None if the range is out of bounds, and Ok or Err in the same way as zvl_binary_search. Indices are returned relative to the start of the range.

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

Get element at index

fn zvl_len(&self) -> usize

The length of this vector

fn zvl_is_ascending(&self) -> bool

Check if this vector is in ascending order according to Ts Ord impl

fn zvl_as_borrowed(&'a self) -> &'a ZeroSlice<T>

Construct a borrowed variant by borrowing from &self.

fn zvl_as_borrowed_inner(&self) -> Option<&'a ZeroSlice<T>>

Extract the inner borrowed variant if possible. Returns None if the data is owned.

fn zvl_from_borrowed(b: &'a ZeroSlice<T>) -> Self

Construct from the borrowed version of the type

fn t_cmp_get(t: &T, g: &Self::GetType) -> Ordering

Compare this type with a Self::GetType. This must produce the same result as if g were converted to Self

fn get_cmp_get(a: &Self::GetType, b: &Self::GetType) -> Ordering

Compare two values of Self::GetType. This must produce the same result as if both a and b were converted to Self

fn t_with_ser<R>(g: &Self::GetType, f: impl FnOnce(&T) -> R) -> R

Obtain a version of T suitable for serialization

fn zvl_is_empty(&self) -> bool

Check if this vector is empty

impl<T> Eq for ZeroSlice<T> where
    T: AsULE + Eq,