export class DiscordEventQueue {

private readonly options: Required<DiscordEventQueueOptions>;

private readonly queue: DiscordEventQueueJob[] = [];

private queueHead = 0;

private processing = 0;

private processedCount = 0;

private droppedCount = 0;

}

enqueue(params: Omit<DiscordEventQueueJob, "resolve" | "reject">): Promise<void> {

if (this.queue.length >= this.options.maxQueueSize) {

if (this.pendingQueueSize >= this.options.maxQueueSize) {

this.droppedCount += 1;

return Promise.reject(

new Error(

getMetrics(): DiscordEventQueueMetrics {

return {

queueSize: this.queue.length,

queueSize: this.pendingQueueSize,

processing: this.processing,

processed: this.processedCount,

dropped: this.droppedCount,

};

}

private get pendingQueueSize(): number {

return Math.max(0, this.queue.length - this.queueHead);

}

private takeNextJob(): DiscordEventQueueJob | undefined {

if (this.queueHead >= this.queue.length) {

this.queue.length = 0;

this.queueHead = 0;

return undefined;

}

const job = this.queue[this.queueHead];

this.queueHead += 1;

if (this.queueHead >= this.queue.length) {

this.queue.length = 0;

this.queueHead = 0;

} else if (this.queueHead > 256 && this.queueHead * 2 > this.queue.length) {

this.queue.splice(0, this.queueHead);

this.queueHead = 0;

}

return job;

}

private processNext(): void {

while (this.processing < this.options.maxConcurrency && this.queue.length > 0) {

const job = this.queue.shift();

while (this.processing < this.options.maxConcurrency && this.pendingQueueSize > 0) {

const job = this.takeNextJob();

if (!job) {

return;

}