| 1 | export const DEFAULT_CIRCULAR_ARRAY_SIZE = 2000; |
| 2 | |
| 3 | /** Array with a maximum length shifting items when full. */ |
| 4 | export class CircularArray<T> extends Array<T> { |
| 5 | public size: number; |
| 6 | |
| 7 | constructor(size: number = DEFAULT_CIRCULAR_ARRAY_SIZE, ...items: T[]) { |
| 8 | super(); |
| 9 | this.checkSize(size); |
| 10 | this.size = size; |
| 11 | if (arguments.length > 1) { |
| 12 | this.push(...items); |
| 13 | } |
| 14 | } |
| 15 | |
| 16 | public push(...items: T[]): number { |
| 17 | const length = super.push(...items); |
| 18 | if (length > this.size) { |
| 19 | super.splice(0, length - this.size); |
| 20 | } |
| 21 | return this.length; |
| 22 | } |
| 23 | |
| 24 | public unshift(...items: T[]): number { |
| 25 | const length = super.unshift(...items); |
| 26 | if (length > this.size) { |
| 27 | super.splice(this.size, items.length); |
| 28 | } |
| 29 | return this.length; |
| 30 | } |
| 31 | |
| 32 | public concat(...items: (T | ConcatArray<T>)[]): CircularArray<T> { |
| 33 | const concatenatedCircularArray = super.concat( |
| 34 | items as T[] |
| 35 | ) as CircularArray<T>; |
| 36 | concatenatedCircularArray.size = this.size; |
| 37 | if (concatenatedCircularArray.length > concatenatedCircularArray.size) { |
| 38 | concatenatedCircularArray.splice( |
| 39 | 0, |
| 40 | concatenatedCircularArray.length - concatenatedCircularArray.size |
| 41 | ); |
| 42 | } |
| 43 | return concatenatedCircularArray; |
| 44 | } |
| 45 | |
| 46 | public splice(start: number, deleteCount?: number, ...items: T[]): T[] { |
| 47 | let itemsRemoved: T[]; |
| 48 | if (arguments.length >= 3 && typeof deleteCount !== 'undefined') { |
| 49 | itemsRemoved = super.splice(start, deleteCount); |
| 50 | // FIXME: that makes the items insert not in place |
| 51 | this.push(...items); |
| 52 | } else if (arguments.length === 2) { |
| 53 | itemsRemoved = super.splice(start, deleteCount); |
| 54 | } else { |
| 55 | itemsRemoved = super.splice(start); |
| 56 | } |
| 57 | return itemsRemoved; |
| 58 | } |
| 59 | |
| 60 | public resize(size: number): void { |
| 61 | this.checkSize(size); |
| 62 | if (size === 0) { |
| 63 | this.length = 0; |
| 64 | } else if (size < this.size) { |
| 65 | for (let i = size; i < this.size; i++) { |
| 66 | super.pop(); |
| 67 | } |
| 68 | } |
| 69 | this.size = size; |
| 70 | } |
| 71 | |
| 72 | public empty(): boolean { |
| 73 | return this.length === 0; |
| 74 | } |
| 75 | |
| 76 | public full(): boolean { |
| 77 | return this.length === this.size; |
| 78 | } |
| 79 | |
| 80 | private checkSize(size: number) { |
| 81 | if (size < 0) { |
| 82 | throw new RangeError('Invalid circular array size'); |
| 83 | } |
| 84 | } |
| 85 | } |