#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
|
|
using System;
|
using System.Runtime.CompilerServices;
|
|
namespace Cysharp.Threading.Tasks.Internal
|
{
|
// optimized version of Standard Queue<T>.
|
internal class MinimumQueue<T>
|
{
|
const int MinimumGrow = 4;
|
const int GrowFactor = 200;
|
|
T[] array;
|
int head;
|
int tail;
|
int size;
|
|
public MinimumQueue(int capacity)
|
{
|
if (capacity < 0) throw new ArgumentOutOfRangeException("capacity");
|
array = new T[capacity];
|
head = tail = size = 0;
|
}
|
|
public int Count
|
{
|
[MethodImpl(MethodImplOptions.AggressiveInlining)]
|
get { return size; }
|
}
|
|
public T Peek()
|
{
|
if (size == 0) ThrowForEmptyQueue();
|
return array[head];
|
}
|
|
[MethodImpl(MethodImplOptions.AggressiveInlining)]
|
public void Enqueue(T item)
|
{
|
if (size == array.Length)
|
{
|
Grow();
|
}
|
|
array[tail] = item;
|
MoveNext(ref tail);
|
size++;
|
}
|
|
[MethodImpl(MethodImplOptions.AggressiveInlining)]
|
public T Dequeue()
|
{
|
if (size == 0) ThrowForEmptyQueue();
|
|
int head = this.head;
|
T[] array = this.array;
|
T removed = array[head];
|
array[head] = default(T);
|
MoveNext(ref this.head);
|
size--;
|
return removed;
|
}
|
|
void Grow()
|
{
|
int newcapacity = (int)((long)array.Length * (long)GrowFactor / 100);
|
if (newcapacity < array.Length + MinimumGrow)
|
{
|
newcapacity = array.Length + MinimumGrow;
|
}
|
SetCapacity(newcapacity);
|
}
|
|
void SetCapacity(int capacity)
|
{
|
T[] newarray = new T[capacity];
|
if (size > 0)
|
{
|
if (head < tail)
|
{
|
Array.Copy(array, head, newarray, 0, size);
|
}
|
else
|
{
|
Array.Copy(array, head, newarray, 0, array.Length - head);
|
Array.Copy(array, 0, newarray, array.Length - head, tail);
|
}
|
}
|
|
array = newarray;
|
head = 0;
|
tail = (size == capacity) ? 0 : size;
|
}
|
|
[MethodImpl(MethodImplOptions.AggressiveInlining)]
|
void MoveNext(ref int index)
|
{
|
int tmp = index + 1;
|
if (tmp == array.Length)
|
{
|
tmp = 0;
|
}
|
index = tmp;
|
}
|
|
void ThrowForEmptyQueue()
|
{
|
throw new InvalidOperationException("EmptyQueue");
|
}
|
}
|
}
|
