Use single entry per cache tag

Author: kitop

src/handlers/cache.cts

@@ -2,13 +2,9 @@ import { getStore } from '@netlify/blobs'
 import { purgeCache } from '@netlify/functions'
 import type { CacheHandler, CacheHandlerContext } from 'next/dist/server/lib/incremental-cache/index.js'
 
-type TagsManifest = {
- version: 1
- items: { [tag: string]: { revalidatedAt: number } }
-}
+type TagManifest = { revalidatedAt: number }
 
-let tagsManifest: TagsManifest | undefined
-const tagsManifestPath = '_netlify/tags-manifest.json'
+const tagsManifestPath = '_netlify-cache/tags'
 const blobStore = getStore('TODO')
 
 /**
@@ -17,11 +13,11 @@ const blobStore = getStore('TODO')
  */
 export default class NetlifyCacheHandler implements CacheHandler {
  options: CacheHandlerContext
+ revalidatedTags: string[]
 
  constructor(options: CacheHandlerContext) {
  this.options = options
-
- this.loadTagsManifest()
+ this.revalidatedTags = options.revalidatedTags
  }
 
  // eslint-disable-next-line require-await, class-methods-use-this
@@ -39,31 +35,29 @@ export default class NetlifyCacheHandler implements CacheHandler {
  public async revalidateTag(tag: string) {
  console.log('NetlifyCacheHandler.revalidateTag', tag)
 
- await this.loadTagsManifest()
- if (!tagsManifest) {
- return
+ const data: TagManifest = {
+ revalidatedAt: Date.now()
  }
 
- const data = tagsManifest.items[tag] || {}
- data.revalidatedAt = Date.now()
- tagsManifest.items[tag] = data
-
  try {
- blobStore.setJSON(tagsManifestPath, tagsManifest)
+ blobStore.setJSON(this.tagManifestPath(tag), data)
  } catch (error: any) {
- console.warn('Failed to update tags manifest.', error)
+ console.warn(`Failed to update tag manifest for ${tag}`, error)
  }
 
  purgeCache({ tags: [tag] })
  }
 
- // eslint-disable-next-line class-methods-use-this
- private async loadTagsManifest() {
+ private async loadTagManifest(tag: string) {
  try {
- tagsManifest = await blobStore.get(tagsManifestPath, {type: 'json'})
+ return await blobStore.get(this.tagManifestPath(tag), {type: 'json'})
  } catch (error: any) {
- console.warn('Failed to fetch tags manifest.', error)
- tagsManifest = { version: 1, items: {} }
+ console.warn(`Failed to fetch tag manifest for ${tag}`, error)
  }
  }
+
+ // eslint-disable-next-line class-methods-use-this
+ private tagManifestPath(tag: string) {
+ return [tagsManifestPath, tag].join('/')
+ }
 }