perf: add adaptive aging factor to priority queue

Signed-off-by: Jérôme Benoit <[email protected]>

Author: jerome-benoit

deno.json

@@ -3,9 +3,7 @@
   "version": "0.5.12",
   "exports": "./src/mod.ts",
   "compilerOptions": {
-    "lib": [
-      "deno.worker"
-    ],
+    "lib": ["deno.worker"],
     "strict": true
   },
   "tasks": {
@@ -27,9 +25,7 @@
     "documentation": "deno doc ./src/mod.ts"
   },
   "test": {
-    "include": [
-      "./tests/**/*.test.mjs"
-    ]
+    "include": ["./tests/**/*.test.mjs"]
   },
   "fmt": {
     "semiColons": false,
@@ -42,18 +38,8 @@
     "@std/testing": "jsr:@std/testing@^1.0.15"
   },
   "publish": {
-    "include": [
-      "LICENSE",
-      "README.md",
-      "deno.json",
-      "src/**/*.ts"
-    ]
+    "include": ["LICENSE", "README.md", "deno.json", "src/**/*.ts"]
   },
   "lock": false,
-  "exclude": [
-    "./coverage",
-    "./dist/browser",
-    "./dist/esm",
-    "./npm"
-  ]
+  "exclude": ["./coverage", "./dist/browser", "./dist/esm", "./npm"]
 }

src/queues/fixed-priority-queue.ts

@@ -10,16 +10,22 @@ import type { IFixedQueue } from './queue-types.ts'
 export class FixedPriorityQueue<T> extends AbstractFixedQueue<T>
   implements IFixedQueue<T> {
   private readonly agingFactor: number
+  private readonly loadExponent: number
 
   /**
    * Constructs a FixedPriorityQueue.
    * @param size - Fixed queue size. @defaultValue defaultQueueSize
    * @param agingFactor - Aging factor to apply to items in priority points per millisecond. A higher value makes items age faster.
    * @returns IFixedQueue.
    */
-  public constructor(size?: number, agingFactor = 0.001) {
+  public constructor(
+    size?: number,
+    agingFactor = 0.001,
+    loadExponent = 1.0 / 1.5,
+  ) {
     super(size)
     this.agingFactor = agingFactor
+    this.loadExponent = loadExponent
   }
 
   /** @inheritdoc */
@@ -29,12 +35,14 @@ export class FixedPriorityQueue<T> extends AbstractFixedQueue<T>
     }
     priority = priority ?? 0
     const now = performance.now()
+    const effectiveAgingFactor = this.agingFactor *
+      (1 + ((this.size + 1) / this.capacity) ** this.loadExponent)
     let insertionPhysicalIndex = -1
     let currentPhysicalIndex = this.start
     for (let i = 0; i < this.size; i++) {
       const node = this.nodeArray[currentPhysicalIndex]!
       const nodeEffectivePriority = node.priority -
-        (now - node.timestamp) * this.agingFactor
+        (now - node.timestamp) * effectiveAgingFactor
       if (nodeEffectivePriority > priority) {
         insertionPhysicalIndex = currentPhysicalIndex
         break