Refactor caching functions for site page metadata and viewport in PPR components

packages/gitbook/src/app/sites/ppr/[mode]/[siteURL]/[siteData]/[tocAPIToken]/[pageAPIToken]/(content)/[pagePath]/page.tsx

@@ -8,7 +8,7 @@ import {
     PPRPageBody,
     cachedGenerateSitePageMetadata,
     cachedGenerateSitePageViewport,
-} from '@/components/SitePage';
+} from '@/components/SitePage/PPRSitePage';
 
 import type { Metadata, Viewport } from 'next';
 

packages/gitbook/src/components/SitePage/PPRSitePage.tsx

@@ -3,9 +3,16 @@ import { SpaceHeader, SpaceTableOfContents } from '@/components/SpaceLayout';
 
 import { getCacheTag } from '@gitbook/cache-tags';
 
-import { cacheLife, cacheTag } from 'next/cache';
+import { cacheLife, cacheTag, unstable_cache } from 'next/cache';
 
-import { SitePage } from './SitePage';
+import type { GitBookSiteContext } from '@/lib/context';
+import type { Metadata, Viewport } from 'next';
+import {
+    SitePage,
+    type SitePageProps,
+    generateSitePageMetadata,
+    generateSitePageViewport,
+} from './SitePage';
 
 /**
  * Render the header from cache without carrying a request-scoped data fetcher into the cache key.
@@ -92,3 +99,47 @@ export async function PPRPageBody(props: { params: RouteLayoutParams; pathname:
 
     return <SitePage context={context} pageParams={{ pathname: props.pathname }} staticRoute />;
 }
+
+// It looks like we cannot use use cache for this one.
+export const cachedGenerateSitePageMetadata = (props: SitePageProps): (() => Promise<Metadata>) => {
+    return unstable_cache(
+        async () => generateSitePageMetadata(props),
+        ['cachedGenerateSitePageMetadata'],
+        {
+            revalidate: 60 * 60 * 24, // Revalidate every 24 hours
+            tags: [
+                getCacheTag({
+                    tag: 'site',
+                    site: props.context.site.id,
+                }),
+                getCacheTag({
+                    tag: 'space',
+                    space: props.context.space.id,
+                }),
+            ],
+        }
+    );
+};
+
+export async function cachedGenerateSitePageViewport(
+    context: GitBookSiteContext
+): Promise<Viewport> {
+    'use cache: remote';
+    cacheLife('days'); // Cache for 1 day
+
+    cacheTag(
+        getCacheTag({
+            tag: 'site',
+            site: context.site.id,
+        })
+    ); // Tag the cache entry for the metadata so it can be invalidated when the site changes
+
+    cacheTag(
+        getCacheTag({
+            tag: 'space',
+            space: context.space.id,
+        })
+    ); // Tag the cache entry for the metadata so it can be invalidated when the space changes
+
+    return generateSitePageViewport(context);
+}

packages/gitbook/src/components/SitePage/SitePage.tsx

@@ -1,5 +1,4 @@
 import type { Metadata, Viewport } from 'next';
-import { cacheLife, cacheTag } from 'next/cache';
 import { notFound, redirect } from 'next/navigation';
 
 import {
@@ -9,7 +8,6 @@ import {
     SiteInsightsDisplayContext,
     type TranslationLanguage,
 } from '@gitbook/api';
-import { getCacheTag } from '@gitbook/cache-tags';
 import { IconsProvider } from '@gitbook/icons';
 
 import { PageContextProvider } from '../PageContext';
@@ -148,29 +146,6 @@ export async function SitePage(props: SitePageProps & { staticRoute: boolean })
     );
 }
 
-export async function cachedGenerateSitePageViewport(
-    context: GitBookSiteContext
-): Promise<Viewport> {
-    'use cache: remote';
-    cacheLife('days'); // Cache for 1 day
-
-    cacheTag(
-        getCacheTag({
-            tag: 'site',
-            site: context.site.id,
-        })
-    ); // Tag the cache entry for the metadata so it can be invalidated when the site changes
-
-    cacheTag(
-        getCacheTag({
-            tag: 'space',
-            space: context.space.id,
-        })
-    ); // Tag the cache entry for the metadata so it can be invalidated when the space changes
-
-    return generateSitePageViewport(context);
-}
-
 export async function generateSitePageViewport(context: GitBookSiteContext): Promise<Viewport> {
     const { customization } = context;
 
@@ -187,27 +162,6 @@ export async function generateSitePageViewport(context: GitBookSiteContext): Pro
     };
 }
 
-export async function cachedGenerateSitePageMetadata(props: SitePageProps): Promise<Metadata> {
-    'use cache: remote';
-    cacheLife('days'); // Cache for 1 day
-
-    cacheTag(
-        getCacheTag({
-            tag: 'site',
-            site: props.context.site.id,
-        })
-    ); // Tag the cache entry for the metadata so it can be invalidated when the site changes
-
-    cacheTag(
-        getCacheTag({
-            tag: 'space',
-            space: props.context.space.id,
-        })
-    ); // Tag the cache entry for the metadata so it can be invalidated when the space changes
-
-    return generateSitePageMetadata(props);
-}
-
 export async function generateSitePageMetadata(props: SitePageProps): Promise<Metadata> {
     const { context, pageTarget, pageMetaLinks } = await getPageDataWithFallback({
         context: props.context,