-const DEFAULT_CIRCULAR_ARRAY_SIZE = 2000;
+// Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
-export default class CircularArray<T> extends Array<T> {
+const DEFAULT_CIRCULAR_ARRAY_SIZE = 1024;
+
+/**
+ * Array with a maximum length and shifting items when full.
+ */
+export class CircularArray<T> extends Array<T> {
public size: number;
- constructor(size?: number) {
+ constructor(size: number = DEFAULT_CIRCULAR_ARRAY_SIZE, ...items: T[]) {
super();
- this.size = size ?? DEFAULT_CIRCULAR_ARRAY_SIZE;
+ this.checkSize(size);
+ this.size = size;
+ if (arguments.length > 1) {
+ this.push(...items);
+ }
}
public push(...items: T[]): number {
- if (this.length + items.length > this.size) {
- super.splice(0, (this.length + items.length) - this.size);
+ const length = super.push(...items);
+ if (length > this.size) {
+ super.splice(0, length - this.size);
}
- return super.push(...items);
+ return this.length;
}
public unshift(...items: T[]): number {
- if (this.length + items.length > this.size) {
- super.splice(this.size - items.length, (this.length + items.length) - this.size);
+ const length = super.unshift(...items);
+ if (length > this.size) {
+ super.splice(this.size, items.length);
}
- return super.unshift(...items);
+ return this.length;
}
- public concat(...items: (T | ConcatArray<T>)[]): T[] {
- if (this.length + items.length > this.size) {
- super.splice(0, (this.length + items.length) - this.size);
+ public concat(...items: (T | ConcatArray<T>)[]): CircularArray<T> {
+ const concatenatedCircularArray = super.concat(items as T[]) as CircularArray<T>;
+ concatenatedCircularArray.size = this.size;
+ if (concatenatedCircularArray.length > concatenatedCircularArray.size) {
+ concatenatedCircularArray.splice(
+ 0,
+ concatenatedCircularArray.length - concatenatedCircularArray.size,
+ );
}
- return super.concat(items as T[]);
+ return concatenatedCircularArray;
}
public splice(start: number, deleteCount?: number, ...items: T[]): T[] {
- this.push(...items);
- return super.splice(start, deleteCount);
+ let itemsRemoved: T[];
+ if (arguments.length >= 3 && deleteCount !== undefined) {
+ itemsRemoved = super.splice(start, deleteCount);
+ // FIXME: that makes the items insert not in place
+ this.push(...items);
+ } else if (arguments.length === 2) {
+ itemsRemoved = super.splice(start, deleteCount);
+ } else {
+ itemsRemoved = super.splice(start);
+ }
+ return itemsRemoved;
}
public resize(size: number): void {
- if (size < 0) {
- throw new RangeError(
- 'circular array size does not allow negative values.'
- );
- }
+ this.checkSize(size);
if (size === 0) {
this.length = 0;
- } else if (size !== this.size) {
- this.slice(-size);
+ } else if (size < this.size) {
+ for (let i = size; i < this.size; i++) {
+ super.pop();
+ }
}
this.size = size;
}
public full(): boolean {
return this.length === this.size;
}
+
+ private checkSize(size: number): void {
+ if (!Number.isSafeInteger(size)) {
+ throw new TypeError(`Invalid circular array size: ${size} is not a safe integer`);
+ }
+ if (size < 0) {
+ throw new RangeError(`Invalid circular array size: ${size} < 0`);
+ }
+ }
}