Task Init

node_modules/generic-pool/lib/PriorityQueue.js

@@ -0,0 +1,69 @@
+"use strict";
+
+const Queue = require("./Queue");
+
+/**
+ * @class
+ * @private
+ */
+class PriorityQueue {
+  constructor(size) {
+    this._size = Math.max(+size | 0, 1);
+    /** @type {Queue[]} */
+    this._slots = [];
+    // initialize arrays to hold queue elements
+    for (let i = 0; i < this._size; i++) {
+      this._slots.push(new Queue());
+    }
+  }
+
+  get length() {
+    let _length = 0;
+    for (let i = 0, slots = this._slots.length; i < slots; i++) {
+      _length += this._slots[i].length;
+    }
+    return _length;
+  }
+
+  enqueue(obj, priority) {
+    // Convert to integer with a default value of 0.
+    priority = (priority && +priority | 0) || 0;
+
+    if (priority) {
+      if (priority < 0 || priority >= this._size) {
+        priority = this._size - 1;
+        // put obj at the end of the line
+      }
+    }
+    this._slots[priority].push(obj);
+  }
+
+  dequeue() {
+    for (let i = 0, sl = this._slots.length; i < sl; i += 1) {
+      if (this._slots[i].length) {
+        return this._slots[i].shift();
+      }
+    }
+    return;
+  }
+
+  get head() {
+    for (let i = 0, sl = this._slots.length; i < sl; i += 1) {
+      if (this._slots[i].length > 0) {
+        return this._slots[i].head;
+      }
+    }
+    return;
+  }
+
+  get tail() {
+    for (let i = this._slots.length - 1; i >= 0; i--) {
+      if (this._slots[i].length > 0) {
+        return this._slots[i].tail;
+      }
+    }
+    return;
+  }
+}
+
+module.exports = PriorityQueue;