X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Fqueue.ts;h=ead4b6375388398483eda10abaaae50e2c779928;hb=64383951fbf11fdf6a804fc6d081635fb925e403;hp=11766e4e9109dc4356be0a4b589ee5e5ed9b7bd3;hpb=4d8bf9e40e07bd233be4494fda4e4270fdd8a355;p=poolifier.git

diff --git a/src/queue.ts b/src/queue.ts
index 11766e4e..ead4b637 100644
--- a/src/queue.ts
+++ b/src/queue.ts
@@ -1,37 +1,74 @@
+// Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
+
 /**
  * Queue
+ *
+ * @typeParam T - Type of queue items.
  */
 export class Queue<T> {
-  private items: Record<number, T>
-  private head: number
-  private tail: number
+  private items!: T[]
+  private offset!: number
+  /** The size of the queue. */
+  public size!: number
+  /** The maximum size of the queue. */
+  public maxSize!: number
 
   public constructor () {
-    this.items = {}
-    this.head = 0
-    this.tail = 0
-  }
-
-  public get size (): number {
-    return this.tail - this.head
+    this.clear()
   }
 
+  /**
+   * Enqueue an item.
+   *
+   * @param item - Item to enqueue.
+   * @returns The new size of the queue.
+   */
   public enqueue (item: T): number {
-    this.items[this.tail] = item
-    this.tail++
+    this.items.push(item)
+    ++this.size
+    if (this.size > this.maxSize) {
+      this.maxSize = this.size
+    }
     return this.size
   }
 
+  /**
+   * Dequeue an item.
+   *
+   * @returns The dequeued item or `undefined` if the queue is empty.
+   */
   public dequeue (): T | undefined {
-    if (this.size <= 0) return undefined
-    const item = this.items[this.head]
-    // eslint-disable-next-line @typescript-eslint/no-dynamic-delete
-    delete this.items[this.head]
-    this.head++
-    if (this.head === this.tail) {
-      this.head = 0
-      this.tail = 0
+    if (this.size <= 0) {
+      return undefined
+    }
+    const item = this.items[this.offset]
+    if (++this.offset * 2 >= this.items.length) {
+      this.items = this.items.slice(this.offset)
+      this.offset = 0
     }
+    --this.size
     return item
   }
+
+  /**
+   * Peeks at the first item.
+   *
+   * @returns The first item or `undefined` if the queue is empty.
+   */
+  public peek (): T | undefined {
+    if (this.size <= 0) {
+      return undefined
+    }
+    return this.items[this.offset]
+  }
+
+  /**
+   * Clears the queue.
+   */
+  public clear (): void {
+    this.items = []
+    this.offset = 0
+    this.size = 0
+    this.maxSize = 0
+  }
 }