Struct slice_ring_buf::SliceRB

pub struct SliceRB<T: Copy + Clone + Default> { /* private fields */ }

A fast ring buffer implementation optimized for working with slices. Copies/reads with slices are implemented with memcpy.

Implementations

impl<T: Copy + Clone + Default> SliceRB<T>

pub fn from_len(len: usize) -> Self

Creates a new SliceRB. All data will be initialized with the default value.

• len - The length of the ring buffer.

Example

use slice_ring_buf::SliceRB;

let rb = SliceRB::<u32>::from_len(3);

assert_eq!(rb.len(), 3);

assert_eq!(rb[0], 0);
assert_eq!(rb[1], 0);
assert_eq!(rb[2], 0);

Panics

• This will panic if len = 0.
• This will panic if this tries to allocate more than isize::MAX bytes.

pub fn from_len_with_capacity(len: usize, capacity: usize) -> Self

Creates a new SliceRB, while reserving extra capacity for future changes to len. All data from [0..len) will be initialized with the default value.

• len - The length of the ring buffer.
• capacity - The allocated capacity of the ring buffer. If this is less than len, then it will be ignored.

Example

use slice_ring_buf::SliceRB;

let rb = SliceRB::<u32>::from_len_with_capacity(3, 10);

assert_eq!(rb.len(), 3);
assert!(rb.capacity() >= 10);

Panics

• This will panic if len = 0.
• This will panic if this tries to allocate more than isize::MAX bytes.

pub unsafe fn from_len_uninit(len: usize) -> Self

Creates a new SliceRB without initializing data.

• len - The length of the ring buffer.

Safety

• Undefined behavior may occur if uninitialized data is read from. By using this you assume the responsibility of making sure any data is initialized before it is read.

Example

use slice_ring_buf::SliceRB;

unsafe {
    let rb = SliceRB::<u32>::from_len_uninit(3);
    assert_eq!(rb.len(), 3);
}

Panics

• This will panic if len = 0.
• This will panic if this tries to allocate more than isize::MAX bytes.

pub unsafe fn from_len_with_capacity_uninit(len: usize, capacity: usize) -> Self

Creates a new SliceRB without initializing data, while reserving extra capacity for future changes to len.

• len - The length of the ring buffer.
• capacity - The allocated capacity of the ring buffer. If this is less than len, then it will be ignored.

Safety

• Undefined behavior may occur if uninitialized data is read from. By using this you assume the responsibility of making sure any data is initialized before it is read.

Example

use slice_ring_buf::SliceRB;

unsafe {
    let rb = SliceRB::<u32>::from_len_with_capacity_uninit(3, 10);
    assert_eq!(rb.len(), 3);
    assert!(rb.capacity() >= 10);
}

Panics

• This will panic if len = 0.
• This will panic if this tries to allocate more than isize::MAX bytes.

pub fn clear_set_len(&mut self, len: usize)

Sets the length of the ring buffer while clearing all values to the default value.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(2);
rb[0] = 1;
rb[1] = 2;

rb.clear_set_len(4);

assert_eq!(rb.len(), 4);

assert_eq!(rb[0], 0);
assert_eq!(rb[1], 0);
assert_eq!(rb[2], 0);
assert_eq!(rb[3], 0);

Panics

• This will panic if len = 0.
• This will panic if this tries to allocate more than isize::MAX bytes.

pub fn set_len(&mut self, len: usize)

Sets the length of the ring buffer.

• If len is less than the current length, then the data will be truncated.
• If len is larger than the current length, then all newly allocated elements appended to the end will be initialized with the default value.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(2);
rb[0] = 1;
rb[1] = 2;

rb.set_len(4);

assert_eq!(rb.len(), 4);

assert_eq!(rb[0], 1);
assert_eq!(rb[1], 2);
assert_eq!(rb[2], 0);
assert_eq!(rb[3], 0);

Panics

• This will panic if len = 0.
• This will panic if this tries to allocate more than isize::MAX bytes.

pub unsafe fn set_len_uninit(&mut self, len: usize)

Sets the length of the ring buffer without initializing any newly allocated data.

• If len is less than the current length, then the data will be truncated.
• If len is larger than the current length, then all newly allocated elements appended to the end will be unitialized.

Safety

• Undefined behavior may occur if uninitialized data is read from. By using this you assume the responsibility of making sure any data is initialized before it is read.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(2);
rb[0] = 1;
rb[1] = 2;

unsafe {
    rb.set_len_uninit(4);

    assert_eq!(rb.len(), 4);

    assert_eq!(rb[0], 1);
    assert_eq!(rb[1], 2);
}

Panics

• This will panic if len = 0.
• This will panic if this tries to allocate more than isize::MAX bytes.

pub fn clear(&mut self)

Clears all values in the ring buffer to the default value.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(2);
rb[0] = 1;
rb[1] = 2;

rb.clear();

assert_eq!(rb[0], 0);
assert_eq!(rb[1], 0);

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements to be inserted in the internal Vec. This is equivalant to Vec::reserve().

The collection may reserve more space to avoid frequent reallocations. After calling reserve, capacity will be greater than or equal to self.len() + additional. Does nothing if capacity is already sufficient.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(2);

rb.reserve(8);

assert!(rb.capacity() >= 10);

Panics

• Panics if the new capacity overflows usize.

pub fn reserve_exact(&mut self, additional: usize)

Reserves capacity for exactly additional more elements to be inserted in the internal Vec. This is equivalant to Vec::reserve_exact().

The collection may reserve more space to avoid frequent reallocations. After calling reserve, capacity will be greater than or equal to self.len() + additional. Does nothing if capacity is already sufficient.

Note that the allocator may give the collection more space than it requests. Therefore, capacity can not be relied upon to be precisely minimal. Prefer reserve if future insertions are expected.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(2);

rb.reserve_exact(8);

assert!(rb.capacity() >= 10);

Panics

• Panics if the new capacity overflows usize.

pub fn shrink_to_fit(&mut self)

Shrinks the capacity of the internal Vec as much as possible. This is equivalant to Vec::shrink_to_fit.

It will drop down as close as possible to the length but the allocator may still inform the vector that there is space for a few more elements.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(2);

rb.reserve(8);
assert!(rb.capacity() >= 10);

rb.shrink_to_fit();
assert!(rb.capacity() >= 2);

pub fn as_slices(&self, start: isize) -> (&[T], &[T])

Returns two slices that contain all the data in the ring buffer starting at the index start.

Returns

• The first slice is the starting chunk of data. This will never be empty.
• The second slice is the second contiguous chunk of data. This may or may not be empty depending if the buffer needed to wrap around to the beginning of its internal memory layout.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let (s1, s2) = rb.as_slices(-4);
assert_eq!(s1, &[1, 2, 3, 4]);
assert_eq!(s2, &[]);

let (s1, s2) = rb.as_slices(3);
assert_eq!(s1, &[4]);
assert_eq!(s2, &[1, 2, 3]);

pub fn as_slices_len(&self, start: isize, len: usize) -> (&[T], &[T])

Returns two slices of data in the ring buffer starting at the index start and with length len.

• start - The starting index
• len - The length of data to read. If len is greater than the length of the ring buffer, then that length will be used instead.

Returns

• The first slice is the starting chunk of data.
• The second slice is the second contiguous chunk of data. This may or may not be empty depending if the buffer needed to wrap around to the beginning of its internal memory layout.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let (s1, s2) = rb.as_slices_len(-4, 3);
assert_eq!(s1, &[1, 2, 3]);
assert_eq!(s2, &[]);

let (s1, s2) = rb.as_slices_len(3, 5);
assert_eq!(s1, &[4]);
assert_eq!(s2, &[1, 2, 3]);

pub fn as_slices_latest(&self, start: isize, len: usize) -> (&[T], &[T])

Returns two slices of data in the ring buffer starting at the index start and with length len. If len is greater than the length of the ring buffer, then the buffer’s length will be used instead, while still preserving the position of the last element.

• start - The starting index
• len - The length of data to read. If len is greater than the length of the ring buffer, then the buffer’s length will be used instead, while still preserving the position of the last element.

Returns

• The first slice is the starting chunk of data.
• The second slice is the second contiguous chunk of data. This may or may not be empty depending if the buffer needed to wrap around to the beginning of its internal memory layout.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let (s1, s2) = rb.as_slices_latest(-4, 3);
assert_eq!(s1, &[1, 2, 3]);
assert_eq!(s2, &[]);

let (s1, s2) = rb.as_slices_latest(0, 5);
assert_eq!(s1, &[2, 3, 4]);
assert_eq!(s2, &[1]);

pub fn as_mut_slices(&mut self, start: isize) -> (&mut [T], &mut [T])

Returns two mutable slices that contain all the data in the ring buffer starting at the index start.

Returns

• The first slice is the starting chunk of data. This will never be empty.
• The second slice is the second contiguous chunk of data. This may or may not be empty depending if the buffer needed to wrap around to the beginning of its internal memory layout.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let (s1, s2) = rb.as_mut_slices(-4);
assert_eq!(s1, &mut [1, 2, 3, 4]);
assert_eq!(s2, &mut []);

let (s1, s2) = rb.as_mut_slices(3);
assert_eq!(s1, &mut [4]);
assert_eq!(s2, &mut [1, 2, 3]);

pub fn as_mut_slices_len( &mut self, start: isize, len: usize ) -> (&mut [T], &mut [T])

Returns two mutable slices of data in the ring buffer starting at the index start and with length len.

• start - The starting index
• len - The length of data to read. If len is greater than the length of the ring buffer, then that length will be used instead.

Returns

• The first slice is the starting chunk of data.
• The second slice is the second contiguous chunk of data. This may or may not be empty depending if the buffer needed to wrap around to the beginning of its internal memory layout.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let (s1, s2) = rb.as_mut_slices_len(-4, 3);
assert_eq!(s1, &mut [1, 2, 3]);
assert_eq!(s2, &mut []);

let (s1, s2) = rb.as_mut_slices_len(3, 5);
assert_eq!(s1, &mut [4]);
assert_eq!(s2, &mut [1, 2, 3]);

pub fn as_mut_slices_latest( &mut self, start: isize, len: usize ) -> (&mut [T], &mut [T])

Returns two mutable slices of data in the ring buffer starting at the index start and with length len. If len is greater than the length of the ring buffer, then the buffer’s length will be used instead, while still preserving the position of the last element.

• start - The starting index
• len - The length of data to read. If len is greater than the length of the ring buffer, then the buffer’s length will be used instead, while still preserving the position of the last element.

Returns

• The first slice is the starting chunk of data.
• The second slice is the second contiguous chunk of data. This may or may not be empty depending if the buffer needed to wrap around to the beginning of its internal memory layout.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let (s1, s2) = rb.as_mut_slices_latest(-4, 3);
assert_eq!(s1, &mut [1, 2, 3]);
assert_eq!(s2, &mut []);

let (s1, s2) = rb.as_mut_slices_latest(0, 5);
assert_eq!(s1, &mut [2, 3, 4]);
assert_eq!(s2, &mut [1]);

pub fn read_into(&self, slice: &mut [T], start: isize)

Copies the data from the ring buffer starting from the index start into the given slice. If the length of slice is larger than the length of the ring buffer, then the data will be reapeated until the given slice is filled.

• slice - This slice to copy the data into.
• start - The index of the ring buffer to start copying from.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let mut read_buf = [0u32; 3];
rb.read_into(&mut read_buf[..], -3);
assert_eq!(read_buf, [2, 3, 4]);

let mut read_buf = [0u32; 9];
rb.read_into(&mut read_buf[..], 2);
assert_eq!(read_buf, [3, 4, 1, 2, 3, 4, 1, 2, 3]);

pub fn write_latest(&mut self, slice: &[T], start: isize)

Copies data from the given slice into the ring buffer starting from the index start.

Earlier data will not be copied if it will be overwritten by newer data, avoiding unecessary memcpy’s. The correct placement of the newer data will still be preserved.

• slice - This slice to copy data from.
• start - The index of the ring buffer to start copying from.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut rb = SliceRB::<u32>::from_len(4);

let input = [1u32, 2, 3];
rb.write_latest(&input[..], -3);
assert_eq!(rb[0], 0);
assert_eq!(rb[1], 1);
assert_eq!(rb[2], 2);
assert_eq!(rb[3], 3);

let input = [1u32, 2, 3, 4, 5, 6, 7, 8, 9];
rb.write_latest(&input[..], 2);
assert_eq!(rb[0], 7);
assert_eq!(rb[1], 8);
assert_eq!(rb[2], 9);
assert_eq!(rb[3], 6);

pub fn write_latest_2(&mut self, first: &[T], second: &[T], start: isize)

Copies data from two given slices into the ring buffer starting from the index start. The first slice will be copied first then second will be copied next.

Earlier data will not be copied if it will be overwritten by newer data, avoiding unecessary memcpy’s. The correct placement of the newer data will still be preserved.

• first - This first slice to copy data from.
• second - This second slice to copy data from.
• start - The index of the ring buffer to start copying from.

Performance

Prefer to use this to manipulate data in bulk over indexing one element at a time.

Example

use slice_ring_buf::SliceRB;

let mut input_rb = SliceRB::<u32>::from_len(4);
input_rb[0] = 1;
input_rb[1] = 2;
input_rb[2] = 3;
input_rb[3] = 4;

let mut output_rb = SliceRB::<u32>::from_len(4);
// s1 == &[1, 2], s2 == &[]
let (s1, s2) = input_rb.as_slices_len(0, 2);
output_rb.write_latest_2(s1, s2, -3);
assert_eq!(output_rb[0], 0);
assert_eq!(output_rb[1], 1);
assert_eq!(output_rb[2], 2);
assert_eq!(output_rb[3], 0);

let mut output_rb = SliceRB::<u32>::from_len(2);
// s1 == &[4],  s2 == &[1, 2, 3]
let (s1, s2) = input_rb.as_slices_len(3, 4);
// rb[1] = 4  ->  rb[0] = 1  ->  rb[1] = 2  ->  rb[0] = 3
output_rb.write_latest_2(s1, s2, 1);
assert_eq!(output_rb[0], 3);
assert_eq!(output_rb[1], 2);

pub fn len(&self) -> usize

Returns the length of the ring buffer.

Example

use slice_ring_buf::SliceRB;
let rb = SliceRB::<u32>::from_len(4);

assert_eq!(rb.len(), 4);

pub fn capacity(&self) -> usize

Returns the allocated capacity of the internal vector.

Please note this is not the same as the length of the buffer. For that use SliceRB::len().

Example

use slice_ring_buf::SliceRB;
let rb = SliceRB::<u32>::from_len(4);

assert!(rb.capacity() >= 4);

pub fn constrain(&self, i: isize) -> isize

Returns the actual index of the ring buffer from the given i index.

• First, a bounds check will be performed. If it is within bounds, then it is simply returned.
• If it is not in bounds, then performance will be limited by the modulo (remainder) operation on an isize value.

Performance

Prefer to manipulate data in bulk with methods that return slices. If you need to index multiple elements one at a time, prefer to use SliceRB::at(&mut i) over SliceRB[i] to reduce the number of modulo operations to perform.

Example

use slice_ring_buf::SliceRB;
let rb = SliceRB::<u32>::from_len(4);

assert_eq!(rb.constrain(2), 2);
assert_eq!(rb.constrain(4), 0);
assert_eq!(rb.constrain(-3), 1);
assert_eq!(rb.constrain(7), 3);

pub fn raw_data(&self) -> &[T]

Returns all the data in the buffer. The starting index will always be 0.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let raw_data = rb.raw_data();
assert_eq!(raw_data, &[1u32, 2, 3, 4]);

pub fn raw_data_mut(&mut self) -> &mut [T]

Returns all the data in the buffer as mutable. The starting index will always be 0.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let raw_data = rb.raw_data_mut();
assert_eq!(raw_data, &mut [1u32, 2, 3, 4]);

pub fn raw_at(&self, i: usize) -> &T

Returns the element at the index of type usize.

Please note this does NOT wrap around. This is equivalent to indexing a normal Vec.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[3] = 4;

assert_eq!(*rb.raw_at(0), 1);
assert_eq!(*rb.raw_at(3), 4);

// These will panic!
// assert_eq!(*rb.raw_at(-3), 2);
// assert_eq!(*rb.raw_at(4), 1);

Panics

• This will panic if i is out of bounds of the internal Vec.

pub fn raw_at_mut(&mut self, i: usize) -> &mut T

Returns the element at the index of type usize as mutable.

Please note this does NOT wrap around. This is equivalent to indexing a normal Vec.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(4);

*rb.raw_at_mut(0) = 1;
*rb.raw_at_mut(3) = 4;

assert_eq!(rb[0], 1);
assert_eq!(rb[3], 4);

// These will panic!
// *rb.raw_at_mut(-3) = 2;
// *rb.raw_at_mut(4) = 1;

Panics

• This will panic if i is out of bounds of the internal Vec.

pub fn at(&self, i: &mut isize) -> &T

Returns the element at the index of type usize while also constraining the index i. This is more efficient than calling both methods individually.

Performance

Prefer to manipulate data in bulk with methods that return slices. If you need to index multiple elements one at a time, prefer to use this over SliceRB[i] to reduce the number of modulo operations to perform.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(4);
rb[0] = 1;
rb[1] = 2;
rb[2] = 3;
rb[3] = 4;

let mut i = -3;
assert_eq!(*rb.at(&mut i), 2);
assert_eq!(i, 1);

pub fn at_mut(&mut self, i: &mut isize) -> &mut T

Returns the element at the index of type usize as mutable while also constraining the index i. This is more efficient than calling both methods individually.

Performance

Prefer to manipulate data in bulk with methods that return slices. If you need to index multiple elements one at a time, prefer to use this over SliceRB[i] to reduce the number of modulo operations to perform.

Example

use slice_ring_buf::SliceRB;
let mut rb = SliceRB::<u32>::from_len(4);

let mut i = -3;
*rb.at_mut(&mut i) = 2;

assert_eq!(rb[1], 2);
assert_eq!(i, 1);

Trait Implementations

impl<T: Clone + Copy + Clone + Default> Clone for SliceRB<T>

fn clone(&self) -> SliceRB<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug + Copy + Clone + Default> Debug for SliceRB<T>

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

Formats the value using the given formatter.

impl<T: Copy + Clone + Default> Index<isize> for SliceRB<T>

type Output = T

The returned type after indexing.

fn index(&self, i: isize) -> &T

Performs the indexing (container[index]) operation.

impl<T: Copy + Clone + Default> IndexMut<isize> for SliceRB<T>

fn index_mut(&mut self, i: isize) -> &mut T

Performs the mutable indexing (container[index]) operation.