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9183b880 JB |
1 | import { |
2 | defaultQueueSize, | |
3 | type FixedQueueNode, | |
4 | type IFixedQueue, | |
5 | } from './utility-types.js' | |
097dea68 JB |
6 | |
7 | /** | |
8 | * Fixed queue. | |
9 | * @typeParam T - Type of fixed queue data. | |
10 | * @internal | |
11 | */ | |
12 | export class FixedQueue<T> implements IFixedQueue<T> { | |
13 | private start!: number | |
14 | /** @inheritdoc */ | |
15 | public readonly capacity: number | |
16 | /** @inheritdoc */ | |
17 | public size!: number | |
18 | /** @inheritdoc */ | |
19 | public nodeArray: FixedQueueNode<T>[] | |
20 | ||
21 | /** | |
22 | * Constructs a fixed queue. | |
23 | * @param size - Fixed queue size. @defaultValue defaultQueueSize | |
24 | * @returns FixedQueue. | |
25 | */ | |
26 | constructor (size: number = defaultQueueSize) { | |
27 | this.checkSize(size) | |
28 | this.capacity = size | |
29 | this.nodeArray = new Array<FixedQueueNode<T>>(this.capacity) | |
30 | this.clear() | |
31 | } | |
32 | ||
33 | /** @inheritdoc */ | |
34 | public empty (): boolean { | |
35 | return this.size === 0 | |
36 | } | |
37 | ||
38 | /** @inheritdoc */ | |
39 | public full (): boolean { | |
40 | return this.size === this.capacity | |
41 | } | |
42 | ||
43 | /** @inheritdoc */ | |
44 | public enqueue (data: T, priority?: number): number { | |
45 | if (this.full()) { | |
46 | throw new Error('Priority queue is full') | |
47 | } | |
48 | let index = this.start + this.size | |
49 | if (index >= this.capacity) { | |
50 | index -= this.capacity | |
51 | } | |
52 | this.nodeArray[index] = { data, priority: priority ?? 0 } | |
53 | return ++this.size | |
54 | } | |
55 | ||
56 | /** @inheritdoc */ | |
57 | public get (index: number): T | undefined { | |
58 | if (this.empty() || index >= this.size) { | |
59 | return undefined | |
60 | } | |
61 | index += this.start | |
62 | if (index >= this.capacity) { | |
63 | index -= this.capacity | |
64 | } | |
65 | return this.nodeArray[index].data | |
66 | } | |
67 | ||
68 | /** @inheritdoc */ | |
69 | public dequeue (): T | undefined { | |
70 | if (this.empty()) { | |
71 | return undefined | |
72 | } | |
73 | const index = this.start | |
74 | --this.size | |
75 | ++this.start | |
76 | if (this.start === this.capacity) { | |
77 | this.start = 0 | |
78 | } | |
79 | return this.nodeArray[index].data | |
80 | } | |
81 | ||
82 | /** @inheritdoc */ | |
83 | public clear (): void { | |
84 | this.start = 0 | |
85 | this.size = 0 | |
86 | } | |
87 | ||
88 | /** @inheritdoc */ | |
89 | public [Symbol.iterator] (): Iterator<T> { | |
90 | let index = this.start | |
91 | let i = 0 | |
92 | return { | |
93 | next: () => { | |
94 | if (i >= this.size) { | |
95 | return { | |
96 | value: undefined, | |
97 | done: true, | |
98 | } | |
99 | } | |
100 | const value = this.nodeArray[index].data | |
101 | ++index | |
102 | ++i | |
103 | if (index === this.capacity) { | |
104 | index = 0 | |
105 | } | |
106 | return { | |
107 | value, | |
108 | done: false, | |
109 | } | |
110 | }, | |
111 | } | |
112 | } | |
113 | ||
114 | /** | |
115 | * Checks the fixed queue size. | |
116 | * @param size - Queue size. | |
117 | */ | |
118 | private checkSize (size: number): void { | |
119 | if (!Number.isSafeInteger(size)) { | |
120 | throw new TypeError( | |
121 | `Invalid fixed queue size: '${size.toString()}' is not an integer` | |
122 | ) | |
123 | } | |
124 | if (size < 0) { | |
9183b880 | 125 | throw new RangeError(`Invalid fixed queue size: ${size.toString()} < 0`) |
097dea68 JB |
126 | } |
127 | } | |
128 | } |