-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Improve queues with circular buffers
- Loading branch information
1 parent
7c04dee
commit 7cf5bc6
Showing
6 changed files
with
175 additions
and
129 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,81 +1,118 @@ | ||
| import { EmptyQueueException } from "./exceptions/EmptyQueueException"; | ||
| import { EmptyQueueException } from './exceptions/EmptyQueueException'; | ||
|
|
||
| export class Queue<T>{ | ||
| private _data: (T | undefined)[]; | ||
| private _head: number; | ||
| private _tail: number; | ||
| class Node<T> { | ||
| data: (T | undefined)[]; | ||
| next: Node<T> | null = null; | ||
|
|
||
| /** | ||
| * Initializes a new instance of the Queue class with the given array. | ||
| * @param array | ||
| */ | ||
| constructor(array: T[]) { | ||
| this._data = array; | ||
| this._head = 0; | ||
| this._tail = array.length; | ||
| } | ||
|
|
||
| /** | ||
| * Adds a new item to the end of the queue. | ||
| * @param value | ||
| */ | ||
| enqueue(value: T) { | ||
| this._data[this._tail] = value; | ||
| this._tail++; | ||
| } | ||
|
|
||
| /** | ||
| * Removes and returns the item at the front of the queue. | ||
| * @throws EmptyQueueException - If the queue is empty. | ||
| * @returns The item that was removed from the front of the queue. | ||
| */ | ||
| dequeue() { | ||
| if (this.isEmpty()) { | ||
| throw new EmptyQueueException(); | ||
| } | ||
|
|
||
| const value = this._data[this._head]; | ||
| this._data[this._head] = undefined; | ||
| this._head++; | ||
| return value; | ||
| } | ||
| constructor(size: number) { | ||
| this.data = new Array<T | undefined>(size); | ||
| } | ||
| } | ||
|
|
||
| export class Queue<T> { | ||
| private _head: Node<T> | null = null; | ||
| private _tail: Node<T> | null = null; | ||
| private _headIndex: number = 0; | ||
| private _tailIndex: number = 0; | ||
| private _arraySize: number; | ||
| private _size: number = 0; | ||
|
|
||
| /** | ||
| * Returns the item at the front of the queue without removing it. | ||
| * @throws EmptyQueueException - If the queue is empty. | ||
| * @returns The item at the front of the queue. | ||
| */ | ||
| peek() { | ||
| if (this.isEmpty()) { | ||
| throw new EmptyQueueException(); | ||
| } | ||
| return this._data[this._head]; | ||
| /** | ||
| * Initializes a new instance of the Queue class with a customizable array size. | ||
| * @param arraySize The size of each array block (default: 4096). | ||
| */ | ||
| constructor(arraySize: number = 4096) { | ||
| this._arraySize = arraySize; | ||
| } | ||
|
|
||
| /** | ||
| * Adds a new item to the end of the queue. | ||
| * @param value The value to be added to the queue. | ||
| */ | ||
| enqueue(value: T) { | ||
| if (this._tail === null) { | ||
| // First element, initialize the linked list | ||
| this._tail = new Node<T>(this._arraySize); | ||
| this._head = this._tail; | ||
| } else if (this._tailIndex === this._arraySize) { | ||
| // Last array is full, add a new node | ||
| const newNode = new Node<T>(this._arraySize); | ||
| this._tail.next = newNode; | ||
| this._tail = newNode; | ||
| this._tailIndex = 0; | ||
| } | ||
|
|
||
| /** | ||
| * Clears all items from the queue and resets its state. | ||
| */ | ||
| clear() { | ||
| this._data = []; | ||
| this._head = 0; | ||
| this._tail = 0; | ||
| this._tail.data[this._tailIndex++] = value; | ||
| this._size++; | ||
| } | ||
|
|
||
| /** | ||
| * Removes and returns the item at the front of the queue. | ||
| * @throws EmptyQueueException - If the queue is empty. | ||
| * @returns The item that was removed from the front of the queue. | ||
| */ | ||
| dequeue(): T | undefined { | ||
| if (this.isEmpty()) { | ||
| throw new EmptyQueueException(); | ||
| } | ||
| const value = this._head!.data[this._headIndex]; | ||
| // This step is optional and may not be required. | ||
| // It doesn't actually have a significant impact on the behavior of the queue, but is added for better memory management. | ||
| this._head!.data[this._headIndex] = undefined; | ||
| this._headIndex++; | ||
| this._size--; | ||
|
|
||
| /** | ||
| * Returns the number of items currently in the queue. | ||
| * @returns The number of items in the queue. | ||
| */ | ||
| size() { | ||
| return this._tail - this._head; | ||
| // If the current array is empty, move to the next node | ||
| if (this._headIndex === this._arraySize) { | ||
| this._head = this._head!.next; | ||
| this._headIndex = 0; | ||
|
|
||
| // If we removed the last node, reset the tail as well | ||
| if (this._head === null) { | ||
| this._tail = null; | ||
| this._tailIndex = 0; | ||
| } | ||
| } | ||
|
|
||
| /** | ||
| * Checks if the queue is empty. | ||
| * @returns `true` if the queue is empty, `false` otherwise. | ||
| */ | ||
| isEmpty() { | ||
| return this._head === this._tail; | ||
| return value; | ||
| } | ||
|
|
||
| /** | ||
| * Returns the item at the front of the queue without removing it. | ||
| * @throws EmptyQueueException - If the queue is empty. | ||
| * @returns The item at the front of the queue. | ||
| */ | ||
| peek(): T | undefined { | ||
| if (this.isEmpty()) { | ||
| throw new EmptyQueueException(); | ||
| } | ||
| return this._head!.data[this._headIndex]; | ||
| } | ||
|
|
||
| /** | ||
| * Clears all items from the queue and resets its state. | ||
| */ | ||
| clear() { | ||
| this._head = null; | ||
| this._tail = null; | ||
| this._headIndex = 0; | ||
| this._tailIndex = 0; | ||
| this._size = 0; | ||
| } | ||
|
|
||
| /** | ||
| * Returns the number of items currently in the queue. | ||
| * @returns The number of items in the queue. | ||
| */ | ||
| size(): number { | ||
| return this._size; | ||
| } | ||
|
|
||
| /** | ||
| * Checks if the queue is empty. | ||
| * @returns `true` if the queue is empty, `false` otherwise. | ||
| */ | ||
| isEmpty(): boolean { | ||
| return this._size === 0; | ||
| } | ||
|
|
||
|
|
||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,6 +1,6 @@ | ||
| export abstract class BaseException extends Error { | ||
| constructor(message: string) { | ||
| super(message); | ||
| this.name = "BaseException"; | ||
| } | ||
| } | ||
| constructor(message: string) { | ||
| super(message); | ||
| this.name = 'BaseException'; | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,8 +1,8 @@ | ||
| import { BaseException } from "./BaseException"; | ||
| import { BaseException } from './BaseException'; | ||
|
|
||
| export class EmptyQueueException extends BaseException { | ||
| constructor() { | ||
| super("Queue is empty"); | ||
| this.name = "EmptyQueueException"; | ||
| } | ||
| } | ||
| constructor() { | ||
| super('Queue is empty'); | ||
| this.name = 'EmptyQueueException'; | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters