migrate Cloudflare Workers implementation to v3 [#80]

serverless/cloudflare/src/index.ts

@@ -0,0 +1,111 @@
+/**
+ * - Run `wrangler dev src/index.ts` in your terminal to start a development server
+ * - Open a browser tab at http://localhost:8787/ to see your worker in action
+ * - Run `wrangler publish src/index.ts --name my-worker` to publish your worker
+ */
+
+import {
+	PMTiles,
+	Source,
+	RangeResponse,
+	ResolvedValueCache,
+} from "../../../js";
+
+export interface Env {
+	BUCKET: R2Bucket;
+	PMTILES_PATH?: string;
+}
+
+class KeyNotFoundError extends Error {
+	constructor(message: string) {
+		super(message);
+	}
+}
+
+const TILE = new RegExp(
+	/^\/([0-9a-zA-Z\/!\-_\.\*\'\(\)]+)\/(\d+)\/(\d+)\/(\d+).([a-z]+)$/
+);
+
+export const pmtiles_path = (p: string | undefined, name: string): string => {
+	if (p) {
+		return p.replace("{name}", name);
+	}
+	return name + ".pmtiles";
+};
+
+const CACHE = new ResolvedValueCache();
+
+export class R2Source implements Source {
+	env: Env;
+	archive_name: string;
+
+	constructor(env: Env, archive_name: string) {
+		this.env = env;
+		this.archive_name = archive_name;
+	}
+
+	getKey() {
+		return "";
+	}
+
+	async getBytes(offset: number, length: number): Promise<RangeResponse> {
+		const resp = await this.env.BUCKET.get(
+			pmtiles_path(this.env.PMTILES_PATH, this.archive_name),
+			{
+				range: { offset: offset, length: length },
+			}
+		);
+		if (!resp) {
+			throw new KeyNotFoundError("Archive not found");
+		}
+		const o = resp as R2ObjectBody;
+		const a = await o.arrayBuffer();
+		return { data: a, etag: o.etag };
+	}
+}
+
+export default {
+	async fetch(
+		request: Request,
+		env: Env,
+		ctx: ExecutionContext
+	): Promise<Response> {
+		const url = new URL(request.url);
+		const match = url.pathname.match(TILE)!;
+
+		if (match) {
+			const archive_name = match[1];
+			const z = +match[2];
+			const x = +match[3];
+			const y = +match[4];
+			const ext = match[5];
+			const source = new R2Source(env, archive_name);
+			const p = new PMTiles(source, CACHE);
+
+			// TODO: optimize by checking header min/maxzoom
+			// TODO: enforce extensions and MIME type using header information
+			try {
+				const tile = await p.getZxy(z, x, y);
+				const headers = new Headers();
+				headers.set("Access-Control-Allow-Origin", "*"); // TODO: make configurable
+				headers.set("Content-Type", "application/protobuf");
+
+				// TODO: optimize by making decompression optional
+				if (tile) {
+					return new Response(tile.data, { headers: headers, status: 200 });
+				} else {
+					return new Response(undefined, { headers: headers, status: 204 });
+				}
+			} catch (e) {
+				if (e instanceof KeyNotFoundError) {
+					return new Response("Archive not found", { status: 404 });
+				} else {
+					throw e;
+				}
+			}
+		}
+
+		// TODO: metadata responses
+		return new Response("Invalid URL", { status: 400 });
+	},
+};