feat(serverAssets): opt-in embed modes for large catalogs

.gitignore

@@ -85,3 +85,4 @@ test/fixture/functions
 # Generated types
 *.d.ts
 !runtime-meta.d.ts
+test/unit/.tmp-server-assets-perf/

docs/1.guide/8.assets.md

@@ -121,3 +121,23 @@ export default defineEventHandler(async (event) => {
   return html
 })
 ```
+
+### Large catalogs (`embed`)
+
+By default each file becomes a lazy Rollup `raw:` module (`embed: true`). For directories with many small files you can opt in:
+
+| `embed` | Behavior |
+| --- | --- |
+| `true` (default) | One `raw:` chunk per file (unchanged) |
+| `"inline"` | Single virtual module (fast builds; larger server entry) |
+| `false` | Copy to `server/assets/<baseName>` and read from disk at runtime (Node/Bun/Deno) |
+
+```ts
+export default defineNitroConfig({
+  serverAssets: [{
+    baseName: 'i18n',
+    dir: './i18n-data',
+    embed: 'inline', // or false
+  }]
+})
+```

src/core/utils/fs-tree.ts

@@ -7,6 +7,13 @@ import prettyBytes from "pretty-bytes";
 import { isTest } from "std-env";
 import { runParallel } from "./parallel";
 
+/**
+ * Build a printable size tree for the server output directory.
+ *
+ * Files under `chunks/raw/` (one Rollup module per `serverAssets` file) are
+ * summarized with `stat` only. Gzipping each of them dominated build wall time
+ * for large catalogs (nitrojs/nitro#1833).
+ */
 export async function generateFSTree(
   dir: string,
   options: { compressedSizes?: boolean } = {}
@@ -15,7 +22,10 @@ export async function generateFSTree(
     return;
   }
 
-  const files = await globby("**/*.*", { cwd: dir, ignore: ["*.map"] });
+  const files = await globby("**/*.*", {
+    cwd: dir,
+    ignore: ["*.map", "chunks/raw/**"],
+  });
 
   const items: { file: string; path: string; size: number; gzip: number }[] =
     [];
@@ -43,9 +53,9 @@ export async function generateFSTree(
   let treeText = "";
 
   for (const [index, item] of items.entries()) {
-    let dir = dirname(item.file);
-    if (dir === ".") {
-      dir = "";
+    let _dir = dirname(item.file);
+    if (_dir === ".") {
+      _dir = "";
     }
     const rpath = relative(process.cwd(), item.path);
     const treeChar = index === items.length - 1 ? "└─" : "├─";
@@ -69,6 +79,25 @@ export async function generateFSTree(
     totalGzip += item.gzip;
   }
 
+  const rawFiles = await globby("chunks/raw/**/*.*", {
+    cwd: dir,
+    ignore: ["*.map"],
+  });
+  if (rawFiles.length > 0) {
+    let rawSize = 0;
+    await runParallel(
+      new Set(rawFiles),
+      async (file) => {
+        rawSize += (await fsp.stat(resolve(dir, file))).size;
+      },
+      { concurrency: 25 }
+    );
+    totalSize += rawSize;
+    treeText += colors.gray(
+      `  ├─ chunks/raw/* (${rawFiles.length} files, ${prettyBytes(rawSize)}, gzip skipped)\n`
+    );
+  }
+
   treeText += `${colors.cyan("Σ Total size:")} ${prettyBytes(
     totalSize + totalNodeModulesSize
   )}`;

src/rollup/plugins/raw.ts

@@ -89,6 +89,9 @@ function isBinary(id: string) {
   return true;
 }
 
+/** Shared with server-assets inline embedding. */
+export { isBinary };
+
 function getHelpers() {
   const js = String.raw;
   return js`