feat: add an experimental KV based tag cache

Author: vicb

examples/overrides/kv-tag-next/package.json

@@ -1,5 +1,5 @@
 {
-	"name": "kv-tag-next",
+	"name": "d1-tag-next",
 	"version": "0.1.0",
 	"private": true,
 	"scripts": {

packages/cloudflare/src/api/overrides/tag-cache/kv-next-tag-cache.ts

@@ -13,12 +13,10 @@ export const BINDING_NAME = "NEXT_TAG_CACHE_KV";
  *
  * Warning:
  * This implementation is considered experimental for now.
- * KV is eventually consistent and can take up to 60s to reflect the last write.
+ * KV is eventually consistency and can take up to 60s to reflect the last write.
  * This means that:
  * - revalidations can take up to 60s to apply
- * - when a page depends on multiple tags they can be inconsistent for up to 60s.
- *   It also means that cached data could be outdated for one tag when other tags
- *   are revalidated resulting in the page being generated based on outdated data.
+ * - when a page depends on multiple tags they can be inconsistent for up to 60s
  */
 export class KVNextModeTagCache implements NextModeTagCache {
 	readonly mode = "nextMode" as const;
@@ -30,6 +28,7 @@ export class KVNextModeTagCache implements NextModeTagCache {
 			return 0;
 		}
 
+		console.log(`[KVNextModeTagCache] getLastRevalidated, tags=${tags}`);
 		try {
 			const keys = tags.map((tag) => this.getCacheKey(tag));
 			// Use the `json` type to get back numbers/null
@@ -63,8 +62,6 @@ export class KVNextModeTagCache implements NextModeTagCache {
 				await kv.put(this.getCacheKey(tag), timeMs);
 			})
 		);
-
-		// TODO: See https://github.com/opennextjs/opennextjs-aws/issues/986
 		await purgeCacheByTags(tags);
 	}