cloudflare--workers-sdk/packages/workers-shared/router-worker/src/analytics.ts

import type { ReadyAnalytics } from "./types";

// This will allow us to make breaking changes to the analytic schema
const VERSION = 1;

export enum STATIC_ROUTING_DECISION {
	NOT_PROVIDED = 0,
	NOT_ROUTED = 1,
	ROUTED = 2,
}

export enum DISPATCH_TYPE {
	ASSETS = "asset",
	WORKER = "worker",
}

// When adding new columns please update the schema
type Data = {
	// -- Indexes --
	accountId?: number;
	scriptId?: number;

	// -- Doubles --
	// double1 - The time it takes for the whole request to complete in milliseconds
	requestTime?: number;
	// double2 - Colo ID
	coloId?: number;
	// double3 - Metal ID
	metalId?: number;
	// double4 - Colo tier (e.g. tier 1, tier 2, tier 3)
	coloTier?: number;
	// double5 - Run user worker ahead of assets
	userWorkerAhead?: boolean;
	// double6 - Routing performed based on the _routes.json (if provided)
	staticRoutingDecision?: STATIC_ROUTING_DECISION;
	// double7 - Whether the request was blocked by abuse mitigation or not
	abuseMitigationBlocked?: boolean;
	// double8 - User worker invocation denied due to free tier limiting
	userWorkerFreeTierLimiting?: boolean;
	// double9 - The time it takes for the request to be handed off the Asset Worker or user Worker in milliseconds
	timeToDispatch?: number;

	// -- Blobs --
	// blob1 - Hostname of the request
	hostname?: string;
	// blob2 - Dispatch type - what kind of thing did we dispatch
	dispatchtype?: DISPATCH_TYPE;
	// blob3 - Error message
	error?: string;
	// blob4 - The current version UUID of router-server
	version?: string;
	// blob5 - Region of the colo (e.g. WEUR)
	coloRegion?: string;
	// blob6 - URL for analysis
	abuseMitigationURLHost?: string;
	// blob7 - XSS detection href parameter value
	xssDetectionImageHref?: string;
	// blob8 - cdn-cgi backslash bypass attempt URL
	cdnCgiBackslashBypassUrl?: string;
};

export class Analytics {
	private data: Data = {};
	private readyAnalytics?: ReadyAnalytics;
	private hasWritten: boolean = false;

	constructor(readyAnalytics?: ReadyAnalytics) {
		this.readyAnalytics = readyAnalytics;
	}

	setData(newData: Partial<Data>) {
		this.data = { ...this.data, ...newData };
	}

	getData(key: keyof Data) {
		return this.data[key];
	}

	write() {
		if (this.hasWritten) {
			// We've already written analytics, don't double send
			return;
		} else if (!this.readyAnalytics) {
			// Local environment, no-op
			return;
		}

		this.hasWritten = true;

		this.readyAnalytics.logEvent({
			version: VERSION,
			accountId: this.data.accountId,
			indexId: this.data.scriptId?.toString(),
			doubles: [
				this.data.requestTime ?? -1, // double1
				this.data.coloId ?? -1, // double2
				this.data.metalId ?? -1, // double3
				this.data.coloTier ?? -1, // double4
				this.data.userWorkerAhead === undefined // double5
					? -1
					: Number(this.data.userWorkerAhead),
				this.data.staticRoutingDecision ?? STATIC_ROUTING_DECISION.NOT_PROVIDED, // double6
				this.data.abuseMitigationBlocked ? 1 : 0, // double7
				this.data.userWorkerFreeTierLimiting ? 1 : 0, // double8
				this.data.timeToDispatch ?? -1, // double9
			],
			blobs: [
				this.data.hostname?.substring(0, 256), // blob1 - trim to 256 bytes
				this.data.dispatchtype, // blob2
				this.data.error?.substring(0, 256), // blob3 - trim to 256 bytes
				this.data.version, // blob4
				this.data.coloRegion, // blob5
				this.data.abuseMitigationURLHost, // blob6
				this.data.xssDetectionImageHref, // blob7
				this.data.cdnCgiBackslashBypassUrl?.substring(0, 256), // blob8 - trim to 256 bytes
			],
		});
	}
}