Class CircularArray<T>

A resizable, array-backed list that stores its elements in a ring buffer (a "deque"-like structure) rather than always starting at index 0. This makes both ends of the collection cheap to grow/shrink from, and Insert(int, T) / RemoveAt(int) only need to shift whichever side of the target index is smaller, instead of always shifting everything after it as a plain array-backed list would.

Inheritance

object

CircularArray<T>

Implements

IList<T>

ICollection<T>

IReadOnlyList<T>

IReadOnlyCollection<T>

IEnumerable<T>

IEnumerable

Inherited Members

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Namespace: FFmpeg.Collections

Assembly: FFmpeg.dll

Syntax

public class CircularArray<T> : IList<T>, ICollection<T>, IReadOnlyList<T>, IReadOnlyCollection<T>, IEnumerable<T>, IEnumerable

Type Parameters

Name	Description
T	The type of elements stored in the collection.

Constructors

CircularArray()

Creates an empty CircularArray<T> with a small default capacity.

Declaration

public CircularArray()

CircularArray(ICollection<T>)

Creates a CircularArray<T> containing a copy of list's elements.

Declaration

public CircularArray(ICollection<T> list)

Parameters

Type	Name	Description
ICollection<T>	list

CircularArray(IEnumerable<T>)

Creates a CircularArray<T> containing a copy of list's elements. The sequence is consumed lazily via repeated Add(T) calls, since its length isn't known up front.

Declaration

public CircularArray(IEnumerable<T> list)

Parameters

Type	Name	Description
IEnumerable<T>	list

CircularArray(IList<T>)

Creates a CircularArray<T> containing a copy of list's elements.

Declaration

public CircularArray(IList<T> list)

Parameters

Type	Name	Description
IList<T>	list

CircularArray(IReadOnlyList<T>)

Creates a CircularArray<T> containing a copy of list's elements.

Declaration

public CircularArray(IReadOnlyList<T> list)

Parameters

Type	Name	Description
IReadOnlyList<T>	list

CircularArray(List<T>)

Creates a CircularArray<T> containing a copy of list's elements.

Declaration

public CircularArray(List<T> list)

Parameters

Type	Name	Description
List<T>	list

CircularArray(int)

Creates an empty CircularArray<T> with the given initial capacity.

Declaration

public CircularArray(int capacity)

Parameters

Type	Name	Description
int	capacity	The number of elements the backing array can hold before it needs to grow.

CircularArray(ReadOnlySpan<T>)

Creates a CircularArray<T> containing a copy of list's elements.

Declaration

public CircularArray(ReadOnlySpan<T> list)

Parameters

Type	Name	Description
ReadOnlySpan<T>	list

Properties

Capacity

The number of elements the backing array can hold before it needs to grow.

Declaration

public int Capacity { get; }

Property Value

Type	Description
int

Count

The number of elements currently stored.

Declaration

public int Count { get; }

Property Value

Type	Description
int

IsReadOnly

Declaration

public bool IsReadOnly { get; }

Property Value

Type	Description
bool

this[int]

Gets a reference to the element at the given logical index, allowing both reading and in-place mutation (e.g. array[i]++).

Declaration

public ref T this[int index] { get; }

Parameters

Type	Name	Description
int	index	A zero-based logical index in the range [0, Count).

Property Value

Type	Description
T

Exceptions

Type	Condition
IndexOutOfRangeException	index is negative or not less than Count.

Methods

Add(T)

Appends item to the end of the collection, growing the backing array first if it's already full.

Declaration

public void Add(T item)

Parameters

Type	Name	Description
T	item	The value to append.

AddRange(IEnumerable<T>)

Adds the elements of items, in order at the end of the list.

Declaration

public void AddRange(IEnumerable<T> items)

Parameters

Type	Name	Description
IEnumerable<T>	items	The elements to insert.

AddRange(ReadOnlySpan<T>)

Adds the elements of items, in order at the end of the list.

Declaration

public void AddRange(ReadOnlySpan<T> items)

Parameters

Type	Name	Description
ReadOnlySpan<T>	items	The elements to insert.

Clear()

Removes all elements. This does not shrink the backing array.

Declaration

public void Clear()

Contains(T)

Determines whether item is present in the collection.

Declaration

public bool Contains(T item)

Parameters

Type	Name	Description
T	item	The value to locate, compared using the default equality comparer for T.

Returns

Type	Description
bool

CopyTo(T[], int)

Copies all elements, in logical order, into array starting at arrayIndex.

Declaration

public void CopyTo(T[] array, int arrayIndex)

Parameters

Type	Name	Description
T[]	array	The destination array. Must have room for Count elements starting at arrayIndex.
int	arrayIndex	The index in array to start writing at.

GetEnumerator()

Returns a struct enumerator over the elements in logical order. Prefer iterating via foreach directly (rather than through IEnumerable<T>) to avoid boxing.

Declaration

public CircularArray<T>.CircularArrayEnumerator GetEnumerator()

Returns

Type	Description
CircularArray<T>.CircularArrayEnumerator

GetSpans(out Span<T>, out Span<T>)

Returns the live elements as one or two contiguous Span<T> slices over the backing array, in logical order. Two spans are returned when the logical range wraps past the end of the backing array; second is empty otherwise.

Declaration

public void GetSpans(out Span<T> first, out Span<T> second)

Parameters

Type	Name	Description
Span<T>	first	The first (and possibly only) contiguous slice of live elements.
Span<T>	second	The remaining live elements after the wrap point, or empty if there is no wrap.

IndexOf(T)

Searches for item and returns its logical index, or -1 if not found.

Declaration

public int IndexOf(T item)

Parameters

Type	Name	Description
T	item	The value to locate, compared using the default equality comparer for T.

Returns

Type	Description
int	The zero-based logical index of the first matching element, or -1 if none is found.

Insert(int, T)

Inserts item at the given logical index, shifting later elements (or earlier elements, whichever is fewer) to make room.

Declaration

public void Insert(int index, T item)

Parameters

Type	Name	Description
int	index	The logical index to insert at. Valid range is [0, Count]; Count appends.
T	item	The value to insert.

Exceptions

Type	Condition
IndexOutOfRangeException	index is negative or greater than Count.

InsertRange(int, IEnumerable<T>)

Inserts the elements of data, in order, starting at the given logical index.

Declaration

public void InsertRange(int index, IEnumerable<T> data)

Parameters

Type	Name	Description
int	index	The logical index to insert at. Valid range is [0, Count]; Count appends.
IEnumerable<T>	data	The elements to insert. If this isn't a T[], List<T>, or ICollection<T>, it is fully enumerated and buffered first, since the length must be known before any shifting happens.

Exceptions

Type	Condition
IndexOutOfRangeException	index is negative or greater than Count.

InsertRange(int, ReadOnlySpan<T>)

Inserts the elements of items, in order, starting at the given logical index.

Declaration

public void InsertRange(int index, ReadOnlySpan<T> items)

Parameters

Type	Name	Description
int	index	The logical index to insert at. Valid range is [0, Count]; Count appends.
ReadOnlySpan<T>	items	The elements to insert.

Exceptions

Type	Condition
IndexOutOfRangeException	index is negative or greater than Count.

Remove(T)

Removes the first occurrence of item, if present.

Declaration

public bool Remove(T item)

Parameters

Type	Name	Description
T	item	The value to remove, compared using the default equality comparer for T.

Returns

Type	Description
bool	true if a matching element was found and removed; otherwise false.

RemoveAt(int)

Removes the element at the given logical index, shifting whichever side of the split (elements before or after index) is smaller to close the gap. If the collection becomes sufficiently sparse, the backing array is also shrunk to reclaim memory.

Declaration

public void RemoveAt(int index)

Parameters

Type	Name	Description
int	index	The logical index of the element to remove. Valid range is [0, Count).

Exceptions

Type	Condition
IndexOutOfRangeException	index is negative or not less than Count.

ShrinkToFit()

Resizes the array to that the data fits perfectly into it.

Declaration

public void ShrinkToFit()

Implements

IList<T>

ICollection<T>

IReadOnlyList<T>

IReadOnlyCollection<T>

IEnumerable<T>

IEnumerable