feat: Persistent cache

packages/vite/src/node/__tests__/utils.spec.ts

@@ -1,4 +1,4 @@
-import { injectQuery, isWindows } from '../utils'
+import { asyncPool, injectQuery, isWindows } from '../utils'
 
 if (isWindows) {
   // this test will work incorrectly on unix systems
@@ -38,3 +38,19 @@ test('path with unicode, space, and %', () => {
     '/usr/vite/東京 %20 hello?direct'
   )
 })
+
+test('asyncPool', async () => {
+  const finished: number[] = []
+  await asyncPool({
+    concurrency: 3,
+    items: [1, 6, 4, 2, 5, 3],
+    fn: (nb) =>
+      new Promise<void>((resolve) =>
+        setTimeout(() => {
+          finished.push(nb)
+          resolve()
+        }, nb * 10)
+      )
+  })
+  expect(finished).toEqual([1, 2, 4, 6, 3, 5])
+})

packages/vite/src/node/server/moduleGraph.ts

@@ -7,6 +7,7 @@ import type { FSWatcher } from 'chokidar'
 import { performance } from 'perf_hooks'
 import { isDirectCSSRequest } from '../plugins/css'
 import {
+  asyncPool,
   cleanUrl,
   createDebugger,
   ensureWatchedFile,
@@ -266,38 +267,43 @@ export class ModuleGraph {
     try {
       cache = JSON.parse(fs.readFileSync(cacheLocation, { encoding: 'utf-8' }))
     } catch {
-      // This can happen when the process is killed while writing to disc.
+      // This can happen when the process is killed while writing to disk.
       isDebug && debugModuleGraph('Corrupted cache, cache not loaded')
       return
     }
     if (cache.configHash !== this.getCacheHash()) {
       isDebug && debugModuleGraph("Config hash didn't match, cache not loaded")
       return
     }
-    for (const [url, value] of Object.entries(cache.files)) {
-      const id = (await this.resolveId(url, false))?.id || url
-      let loadResult = await this.load(id)
-      if (!loadResult) {
-        try {
-          loadResult = await fs.promises.readFile(id, 'utf-8')
-        } catch (e) {
-          if (e.code !== 'ENOENT') throw e
+    await asyncPool({
+      concurrency: 10,
+      items: Object.entries(cache.files),
+      fn: async ([url, value]) => {
+        const id = (await this.resolveId(url, false))?.id || url
+        let loadResult = await this.load(id)
+        if (!loadResult) {
+          try {
+            loadResult = await fs.promises.readFile(id, 'utf-8')
+          } catch (e) {
+            if (e.code !== 'ENOENT') throw e
+          }
         }
+        if (!loadResult) {
+          isDebug && debugModuleGraph(`Module ${url} not found`)
+          return
+        }
+        const code =
+          typeof loadResult === 'object' ? loadResult.code : loadResult
+        if (getEtag(code, { weak: true }) !== value.sourceEtag) {
+          isDebug && debugModuleGraph(`Module ${url} changed`)
+          return
+        }
+        const module = await this.ensureEntryFromUrl(url)
+        ensureWatchedFile(this.watcher, module.file, this.config.root)
+        module.sourceEtag = value.sourceEtag
+        module.transformResult = value.transformResult
       }
-      if (!loadResult) {
-        isDebug && debugModuleGraph(`Module ${url} not found`)
-        continue
-      }
-      const code = typeof loadResult === 'object' ? loadResult.code : loadResult
-      if (getEtag(code, { weak: true }) !== value.sourceEtag) {
-        isDebug && debugModuleGraph(`Module ${url} changed`)
-        continue
-      }
-      const module = await this.ensureEntryFromUrl(url)
-      ensureWatchedFile(this.watcher, module.file, this.config.root)
-      module.sourceEtag = value.sourceEtag
-      module.transformResult = value.transformResult
-    }
+    })
     isDebug &&
       debugModuleGraph(
         timeFrom(start),

packages/vite/src/node/server/transformRequest.ts

@@ -187,12 +187,12 @@ async function doTransform(
       url
     ))
   } else {
-    const transformResult = (mod.transformResult = {
+    mod.transformResult = {
       code,
       map: map as SourceMap,
       etag: getEtag(code, { weak: true })
-    })
+    }
     server.moduleGraph.queueSaveCache()
-    return transformResult
+    return mod.transformResult
   }
 }

packages/vite/src/node/utils.ts

@@ -663,3 +663,26 @@ export function parseRequest(id: string): Record<string, string> | null {
   }
   return Object.fromEntries(new URLSearchParams(search.slice(1)))
 }
+
+// TS rewrite of https://github.com/rxaviers/async-pool/blob/master/lib/es7.js
+// Credits: Rafael Xavier de Souza http://rafael.xavier.blog.br
+export async function asyncPool<Item, Result>({
+  concurrency,
+  items,
+  fn
+}: {
+  concurrency: number
+  items: Item[]
+  fn: (item: Item) => Promise<Result>
+}): Promise<Result[]> {
+  const promises: Promise<Result>[] = []
+  const pool = new Set<Promise<Result>>()
+  for (const item of items) {
+    const promise = fn(item)
+    promises.push(promise)
+    pool.add(promise)
+    promise.then(() => pool.delete(promise))
+    if (pool.size >= concurrency) await Promise.race(pool)
+  }
+  return Promise.all(promises)
+}