feat(workers): cache

cloudflare-workers/src/cache.ts

@@ -0,0 +1,23 @@
+import { getPaths } from './db';
+
+export async function purgeAllCommentCache(env: Env, cache: Cache, baseUrl: string) {
+	const paths = await getPaths(env);
+
+	await Promise.all(
+		paths.map((path) => {
+			purgeCommentCache(env, cache, baseUrl, path);
+		}),
+	);
+}
+
+export async function purgeCommentCache(env: Env, cache: Cache, baseUrl: string, path: string) {
+	await cache.delete(`${baseUrl}/comment${path}`);
+}
+
+export async function putCommentCache(env: Env, cache: Cache, baseUrl: string, path: string, resp: Response): Promise<void> {
+	await cache.put(`${baseUrl}/comment${path}`, resp);
+}
+
+export async function matchCommentCache(env: Env, cache: Cache, baseUrl: string, path: string): Promise<Response | undefined> {
+	return await cache.match(`${baseUrl}/comment${path}`);
+}

cloudflare-workers/src/db.ts

@@ -78,3 +78,9 @@ export async function getMeta(env: Env, key: string): Promise<string | undefined
 
 	return meta?.value;
 }
+
+export async function getPaths(env: Env): Promise<string[]> {
+	const db = env.DB;
+
+	return (await db.prepare('SELECT path FROM pages').all()).results.map((page) => page.path as string);
+}

cloudflare-workers/src/index.ts

@@ -12,18 +12,30 @@
  */
 
 import { AutoRouter, error } from 'itty-router';
-import { GetCommentBody, GetCommentRespBody, GetCommitHashRespBody, PostCommentBody, PutCommitHashBody, ResponseBody } from './types';
-import { getComment, getMeta, postComment } from './db';
+import { GetCommentBody, GetCommentRespBody, PostCommentBody, PutCommitHashBody, ResponseBody } from './types';
+import { getComment, postComment } from './db';
 import { validateSecret, setCommitHash, compareCommitHash } from './administration';
+import { matchCommentCache, purgeAllCommentCache, purgeCommentCache, putCommentCache } from './cache';
 
 const router = AutoRouter();
 
-router.post('/comment', async (req, env, ctx) => {
+router.post('/comment/:path', async (req, env, ctx) => {
+	const params = req.params as GetCommentBody;
+
+	if (params == undefined || params.path == undefined) {
+		return error(400, 'Invalid request body');
+	}
+
+	params.path = decodeURIComponent(params.path);
+
+	if (!params.path.startsWith('/')) {
+		return error(400, 'Invalid path');
+	}
+
 	const body = await req.json<PostCommentBody>();
 
 	if (
 		body == undefined ||
-		body.path == undefined ||
 		body.offset == undefined ||
 		body.commenter == undefined ||
 		body.comment == undefined ||
@@ -35,10 +47,6 @@ router.post('/comment', async (req, env, ctx) => {
 		return error(400, 'Invalid request body');
 	}
 
-	if (!body.path.startsWith('/')) {
-		return error(400, 'Invalid path');
-	}
-
 	if (body.offset.start < 0 || body.offset.end < 0 || body.offset.start >= body.offset.end) {
 		return error(400, 'Invalid offset');
 	}
@@ -56,7 +64,7 @@ router.post('/comment', async (req, env, ctx) => {
 	}
 
 	await postComment(env, {
-		path: body.path,
+		path: params.path,
 		offset: body.offset,
 		commenter: {
 			name: body.commenter.name,
@@ -66,6 +74,9 @@ router.post('/comment', async (req, env, ctx) => {
 		comment: body.comment,
 	});
 
+	const cache = caches.default;
+	ctx.waitUntil(purgeCommentCache(env, cache, new URL(req.url).origin, params.path));
+
 	return {
 		status: 200,
 	} satisfies ResponseBody;
@@ -80,12 +91,25 @@ router.get('/comment/:path', async (req, env, ctx) => {
 
 	params.path = decodeURIComponent(params.path);
 
-	const rst = await getComment(env, params);
+	const cache = caches.default;
+	let resp = await matchCommentCache(env, cache, new URL(req.url).origin, params.path);
+
+	if (!resp) {
+		resp = new Response(
+			JSON.stringify({
+				status: 200,
+				data: await getComment(env, params),
+			} satisfies ResponseBody<GetCommentRespBody>),
+			{
+				headers: {
+					'Content-Type': 'application/json',
+				},
+			},
+		);
+		ctx.waitUntil(putCommentCache(env, cache, new URL(req.url).origin, params.path, resp.clone()));
+	}
 
-	return {
-		status: 200,
-		data: rst,
-	} satisfies ResponseBody<GetCommentRespBody>;
+	return resp;
 });
 
 router.put('/meta/commithash', async (req, env, ctx) => {
@@ -122,4 +146,29 @@ router.put('/meta/commithash', async (req, env, ctx) => {
 	} satisfies ResponseBody;
 });
 
+router.delete('/cache', async (req, env, ctx) => {
+	const authorization = req.headers.get('Authorization');
+
+	if (!authorization) {
+		return error(401, 'Unauthorized');
+	}
+
+	const [scheme, secret] = authorization.split(' ');
+
+	if (scheme !== 'Bearer' || !secret) {
+		return error(400, 'Malformed authorization header');
+	}
+
+	if (validateSecret(env, secret) !== true) {
+		return error(401, 'Unauthorized');
+	}
+
+	const cache = caches.default;
+	await purgeAllCommentCache(env, cache, new URL(req.url).origin);
+
+	return {
+		status: 200,
+	} satisfies ResponseBody;
+});
+
 export default { ...router } satisfies ExportedHandler<Env>;

cloudflare-workers/src/types.ts

@@ -1,5 +1,4 @@
 export type PostCommentBody = {
-	path: string;
 	offset: {
 		start: number;
 		end: number;
@@ -16,7 +15,9 @@ export type PostComment = {
 		user_agent: string;
 		ip_address: string | null;
 	};
-} & Omit<PostCommentBody, 'commit_hash'>;
+} & Omit<PostCommentBody, 'commit_hash'> & {
+		path: string;
+	};
 
 export type GetCommentBody = {
 	path: string;