1 // Copyright Jerome Benoit. 2024. All Rights Reserved.
3 import { FixedPriorityQueue
} from
'./fixed-priority-queue.js'
8 export const defaultBucketSize
= 2048
11 * Priority queue node.
12 * @typeParam T - Type of priority queue node data.
15 export interface PriorityQueueNode
<T
> extends FixedPriorityQueue
<T
> {
16 next
?: FixedPriorityQueue
<T
>
21 * @typeParam T - Type of priority queue data.
24 export class PriorityQueue
<T
> {
25 private head
!: PriorityQueueNode
<T
>
26 private tail
!: PriorityQueueNode
<T
>
27 private readonly bucketSize
: number
28 /** The priority queue maximum size. */
29 public maxSize
!: number
32 * Constructs a priority queue.
33 * @param bucketSize - Prioritized bucket size. @defaultValue defaultBucketSize
34 * @param enablePriority - Whether to enable priority. @defaultValue false
35 * @returns PriorityQueue.
38 bucketSize
: number = defaultBucketSize
,
39 enablePriority
= false
41 if (!Number.isSafeInteger(bucketSize
)) {
43 `Invalid bucket size: '${bucketSize.toString()}' is not an integer`
47 throw new RangeError(`Invalid bucket size: ${bucketSize.toString()} < 0`)
49 this.bucketSize
= bucketSize
50 this.head
= this.tail
= new FixedPriorityQueue(
58 * The priority queue size.
60 public get
size (): number {
61 let node
: PriorityQueueNode
<T
> | undefined = this.tail
63 while (node
!= null) {
70 public get
enablePriority (): boolean {
71 return this.head
.enablePriority
74 public set
enablePriority (enablePriority
: boolean) {
75 if (this.head
.enablePriority
=== enablePriority
) {
78 let node
: PriorityQueueNode
<T
> | undefined = this.tail
79 while (node
!= null) {
80 node
.enablePriority
= enablePriority
86 * The number of filled prioritized buckets.
88 public get
buckets (): number {
89 return Math.trunc(this.size
/ this.bucketSize
)
93 * Enqueue data into the priority queue.
94 * @param data - Data to enqueue.
95 * @param priority - Priority of the data. Lower values have higher priority.
96 * @returns The new size of the priority queue.
98 public enqueue (data
: T
, priority
?: number): number {
99 if (this.head
.full()) {
100 this.head
= this.head
.next
= new FixedPriorityQueue(
105 this.head
.enqueue(data
, priority
)
106 const size
= this.size
107 if (size
> this.maxSize
) {
114 * Dequeue data from the priority queue.
115 * @param bucket - The prioritized bucket to dequeue from.
116 * @returns The dequeued data or `undefined` if the priority queue is empty.
118 public dequeue (bucket
?: number): T
| undefined {
119 let tail
: PriorityQueueNode
<T
> | undefined = this.tail
120 let tailChanged
= false
121 if (bucket
!= null && bucket
> 0) {
122 let currentBucket
= 1
123 while (tail
!= null) {
124 if (currentBucket
=== bucket
) {
132 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
133 const data
= tail
!.dequeue()
134 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
135 if (tail
!.empty() && tail
!.next
!= null) {
137 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
138 this.tail
= tail
!.next
140 let node
: PriorityQueueNode
<T
> | undefined = this.tail
141 while (node
!= null) {
142 if (node
.next
=== tail
) {
143 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
144 node
.next
= tail
!.next
150 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
157 * Clears the priority queue.
159 public clear (): void {
160 this.head
= this.tail
= new FixedPriorityQueue(
168 * Returns an iterator for the priority queue.
169 * @returns An iterator for the priority queue.
170 * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols
172 public [Symbol
.iterator
] (): Iterator
<T
> {
177 const value
= node
.get(index
) as T
185 if (index
=== node
.capacity
&& node
.next
!= null) {