feat: use the cache api if there is no kv cache available

.changeset/gold-onions-lick.md

@@ -0,0 +1,7 @@
+---
+"@opennextjs/cloudflare": minor
+---
+
+feat: use the cache api if there is no kv cache available
+
+Instead of requiring a KV cache is available in the environment for Next.js caching to work, the cache handle will default to using the Cache API.

packages/cloudflare/src/cli/templates/cache-handler/cache-store.ts

@@ -0,0 +1,65 @@
+import type { IncrementalCacheValue } from "next/dist/server/response-cache";
+
+export type CacheEntry = {
+  lastModified: number;
+  value: IncrementalCacheValue | null;
+};
+
+export type CacheStore = {
+  get: (key: string) => Promise<CacheEntry | null>;
+  put: (key: string, entry: CacheEntry, ttl?: number) => Promise<void>;
+};
+
+export function getCacheStore() {
+  const kvName = process.env.__OPENNEXT_KV_BINDING_NAME;
+  if (process.env[kvName]) {
+    return new KVStore(process.env[kvName] as unknown as KVNamespace);
+  }
+
+  return new CacheAPIStore();
+}
+
+const oneYearInMs = 31536000;
+
+class KVStore implements CacheStore {
+  constructor(private store: KVNamespace) {}
+
+  get(key: string) {
+    return this.store.get<CacheEntry>(key, "json");
+  }
+
+  put(key: string, entry: CacheEntry, ttl = oneYearInMs) {
+    return this.store.put(key, JSON.stringify(entry), {
+      expirationTtl: ttl,
+    });
+  }
+}
+
+class CacheAPIStore implements CacheStore {
+  constructor(private name = "__opennext_cache") {}
+
+  async get(key: string) {
+    const cache = await caches.open(this.name);
+    const response = await cache.match(this.createCacheKey(key));
+
+    if (response) {
+      return response.json<CacheEntry>();
+    }
+
+    return null;
+  }
+
+  async put(key: string, entry: CacheEntry, ttl = oneYearInMs) {
+    const cache = await caches.open(this.name);
+
+    const response = new Response(JSON.stringify(entry), {
+      headers: { "cache-control": `max-age=${ttl}` },
+    });
+
+    return cache.put(this.createCacheKey(key), response);
+  }
+
+  private createCacheKey(key: string) {
+    return `https://${this.name}.local/entry/${key}`;
+  }
+}

packages/cloudflare/src/cli/templates/cache-handler/open-next-cache-handler.ts

@@ -1,4 +1,3 @@
-import type { KVNamespace } from "@cloudflare/workers-types";
 import type {
   CacheHandler,
   CacheHandlerContext,
@@ -14,20 +13,17 @@ import {
   RSC_SUFFIX,
   SEED_DATA_DIR,
 } from "../../constants/incremental-cache";
+import type { CacheEntry, CacheStore } from "./cache-store";
+import { getCacheStore } from "./cache-store";
 import { getSeedBodyFile, getSeedMetaFile, getSeedTextFile, parseCtx } from "./utils";
 
-type CacheEntry = {
-  lastModified: number;
-  value: IncrementalCacheValue | null;
-};
-
 export class OpenNextCacheHandler implements CacheHandler {
-  protected kv: KVNamespace | undefined;
+  protected cache: CacheStore;
 
   protected debug: boolean = !!process.env.NEXT_PRIVATE_DEBUG_CACHE;
 
   constructor(protected ctx: CacheHandlerContext) {
-    this.kv = process.env[process.env.__OPENNEXT_KV_BINDING_NAME] as KVNamespace | undefined;
+    this.cache = getCacheStore();
   }
 
   async get(...args: Parameters<CacheHandler["get"]>): Promise<CacheHandlerValue | null> {
@@ -36,13 +32,11 @@ export class OpenNextCacheHandler implements CacheHandler {
 
     if (this.debug) console.log(`cache - get: ${key}, ${ctx?.kind}`);
 
-    if (this.kv !== undefined) {
-      try {
-        const value = await this.kv.get<CacheEntry>(key, "json");
-        if (value) return value;
-      } catch (e) {
-        console.error(`Failed to get value for key = ${key}: ${e}`);
-      }
+    try {
+      const value = await this.cache.get(key);
+      if (value) return value;
+    } catch (e) {
+      console.error(`Failed to get value for key = ${key}: ${e}`);
     }
 
     // Check for seed data from the file-system.
@@ -118,10 +112,6 @@ export class OpenNextCacheHandler implements CacheHandler {
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
     const [key, entry, _ctx] = args;
 
-    if (this.kv === undefined) {
-      return;
-    }
-
     if (this.debug) console.log(`cache - set: ${key}`);
 
     const data: CacheEntry = {
@@ -130,17 +120,14 @@ export class OpenNextCacheHandler implements CacheHandler {
     };
 
     try {
-      await this.kv.put(key, JSON.stringify(data));
+      await this.cache.put(key, data);
     } catch (e) {
       console.error(`Failed to set value for key = ${key}: ${e}`);
     }
   }
 
   async revalidateTag(...args: Parameters<CacheHandler["revalidateTag"]>) {
     const [tags] = args;
-    if (this.kv === undefined) {
-      return;
-    }
 
     if (this.debug) console.log(`cache - revalidateTag: ${JSON.stringify([tags].flat())}`);
   }