Offload Oxide scanning to separate process

Author: thecrypticace

packages/tailwindcss-language-server/package.json

@@ -13,8 +13,9 @@
   },
   "homepage": "https://github.com/tailwindlabs/tailwindcss-intellisense/tree/HEAD/packages/tailwindcss-language-server#readme",
   "scripts": {
-    "build": "pnpm run clean && pnpm run _esbuild && pnpm run _esbuild:css",
+    "build": "pnpm run clean && pnpm run _esbuild && pnpm run _esbuild:oxide && pnpm run _esbuild:css",
     "_esbuild": "node ../../esbuild.mjs src/server.ts --outfile=bin/tailwindcss-language-server --minify",
+    "_esbuild:oxide": "node ../../esbuild.mjs src/oxide-helper.ts --outfile=bin/oxide-helper.js --minify",
     "_esbuild:css": "node ../../esbuild.mjs src/language/css.ts --outfile=bin/css-language-server --minify",
     "clean": "rimraf bin",
     "prepublishOnly": "pnpm run build",

packages/tailwindcss-language-server/src/oxide-helper.ts

@@ -0,0 +1,14 @@
+#!/usr/bin/env node
+
+import * as rpc from 'vscode-jsonrpc/node'
+import { scan, type ScanOptions, type ScanResult } from './oxide'
+
+let connection = rpc.createMessageConnection(
+  new rpc.IPCMessageReader(process),
+  new rpc.IPCMessageWriter(process),
+)
+
+let scanRequest = new rpc.RequestType<ScanOptions, ScanResult, void>('scan')
+connection.onRequest<ScanOptions, ScanResult, void>(scanRequest, (options) => scan(options))
+
+connection.listen()

packages/tailwindcss-language-server/src/oxide-session.ts

@@ -0,0 +1,67 @@
+import * as rpc from 'vscode-jsonrpc/node'
+import * as proc from 'node:child_process'
+import * as path from 'node:path'
+import { type ScanOptions, type ScanResult } from './oxide'
+
+/**
+ * This helper starts a session in which we can use Oxide in *another process*
+ * to communicate content scanning results.
+ *
+ * Thie exists for two reasons:
+ * - The Oxide API has changed over time so this function presents a unified
+ *   interface that works with all versions of the Oxide API. The results may
+ *   vary but the structure of the results will always be identical.
+ *
+ * - Requiring a native node module on Windows permanently keeps an open handle
+ *   to the binary for the duration of the process. This prevents unlinking the
+ *   file like happens when running `npm ci`. Running an ephemeral process lets
+ *   us sidestep the problem as the process will only be running as needed.
+ */
+export class OxideSession {
+  helper: proc.ChildProcess | null = null
+  connection: rpc.MessageConnection | null = null
+
+  public async scan(options: ScanOptions): Promise<ScanResult> {
+    await this.startIfNeeded()
+
+    return await this.connection.sendRequest('scan', options)
+  }
+
+  async startIfNeeded(): Promise<void> {
+    if (this.connection) return
+
+    // TODO: Can we find a way to not require a build first?
+    // let module = path.resolve(path.dirname(__filename), './oxide-helper.ts')
+    let module = path.resolve(path.dirname(__filename), '../bin/oxide-helper.js')
+
+    let helper = proc.fork(module)
+    let connection = rpc.createMessageConnection(
+      new rpc.IPCMessageReader(helper),
+      new rpc.IPCMessageWriter(helper),
+    )
+
+    helper.on('disconnect', () => {
+      connection.dispose()
+      this.connection = null
+      this.helper = null
+    })
+
+    helper.on('exit', () => {
+      connection.dispose()
+      this.connection = null
+      this.helper = null
+    })
+
+    connection.listen()
+
+    this.helper = helper
+    this.connection = connection
+  }
+
+  async stop() {
+    if (!this.helper) return
+
+    this.helper.disconnect()
+    this.helper.kill()
+  }
+}

packages/tailwindcss-language-server/src/oxide.ts

@@ -111,14 +111,14 @@ interface SourceEntry {
   negated: boolean
 }
 
-interface ScanOptions {
+export interface ScanOptions {
   oxidePath: string
   oxideVersion: string
   basePath: string
   sources: Array<SourceEntry>
 }
 
-interface ScanResult {
+export interface ScanResult {
   files: Array<string>
   globs: Array<GlobEntry>
 }

packages/tailwindcss-language-server/src/project-locator.ts

@@ -16,6 +16,7 @@ import { normalizeDriveLetter, normalizePath, pathToFileURL } from './utils'
 import postcss from 'postcss'
 import * as oxide from './oxide'
 import { analyzeStylesheet, TailwindStylesheet } from './version-guesser'
+import { OxideSession } from './oxide-session'
 
 export interface ProjectConfig {
   /** The folder that contains the project */
@@ -60,7 +61,10 @@ export class ProjectLocator {
     let configs = await this.findConfigs()
 
     // Create a project for each of the config files
-    let results = await Promise.allSettled(configs.map((config) => this.createProject(config)))
+    let session = new OxideSession()
+    let results = await Promise.allSettled(
+      configs.map((config) => this.createProject(config, session)),
+    )
     let projects: ProjectConfig[] = []
 
     for (let result of results) {
@@ -71,6 +75,8 @@ export class ProjectLocator {
       }
     }
 
+    console.log(projects[0])
+
     if (projects.length === 1) {
       projects[0].additionalSelectors.push({
         pattern: normalizePath(path.join(this.base, '**')),
@@ -98,6 +104,8 @@ export class ProjectLocator {
       }
     }
 
+    await session.stop()
+
     return projects
   }
 
@@ -148,7 +156,10 @@ export class ProjectLocator {
     }
   }
 
-  private async createProject(config: ConfigEntry): Promise<ProjectConfig | null> {
+  private async createProject(
+    config: ConfigEntry,
+    session: OxideSession,
+  ): Promise<ProjectConfig | null> {
     let tailwind = await this.detectTailwindVersion(config)
 
     let possibleVersions = config.entries.flatMap((entry) => entry.meta?.versions ?? [])
@@ -218,7 +229,12 @@ export class ProjectLocator {
     // Look for the package root for the config
     config.packageRoot = await getPackageRoot(path.dirname(config.path), this.base)
 
-    let selectors = await calculateDocumentSelectors(config, tailwind.features, this.resolver)
+    let selectors = await calculateDocumentSelectors(
+      config,
+      tailwind.features,
+      this.resolver,
+      session,
+    )
 
     return {
       config,
@@ -520,10 +536,11 @@ function contentSelectorsFromConfig(
   entry: ConfigEntry,
   features: Feature[],
   resolver: Resolver,
+  session: OxideSession,
   actualConfig?: any,
 ): AsyncIterable<DocumentSelector> {
   if (entry.type === 'css') {
-    return contentSelectorsFromCssConfig(entry, resolver)
+    return contentSelectorsFromCssConfig(entry, resolver, session)
   }
 
   if (entry.type === 'js') {
@@ -582,6 +599,7 @@ async function* contentSelectorsFromJsConfig(
 async function* contentSelectorsFromCssConfig(
   entry: ConfigEntry,
   resolver: Resolver,
+  session: OxideSession,
 ): AsyncIterable<DocumentSelector> {
   let auto = false
   for (let item of entry.content) {
@@ -606,6 +624,7 @@ async function* contentSelectorsFromCssConfig(
         entry.path,
         sources,
         resolver,
+        session,
       )) {
         yield {
           pattern,
@@ -621,14 +640,15 @@ async function* detectContentFiles(
   inputFile: string,
   sources: SourcePattern[],
   resolver: Resolver,
+  session: OxideSession,
 ): AsyncIterable<string> {
   try {
     let oxidePath = await resolver.resolveJsId('@tailwindcss/oxide', base)
     oxidePath = pathToFileURL(oxidePath).href
     let oxidePackageJsonPath = await resolver.resolveJsId('@tailwindcss/oxide/package.json', base)
     let oxidePackageJson = JSON.parse(await fs.readFile(oxidePackageJsonPath, 'utf8'))
 
-    let result = await oxide.scan({
+    let result = await session.scan({
       oxidePath,
       oxideVersion: oxidePackageJson.version,
       basePath: base,
@@ -654,8 +674,8 @@ async function* detectContentFiles(
       base = normalizeDriveLetter(base)
       yield `${base}/${pattern}`
     }
-  } catch {
-    //
+  } catch (err) {
+    console.log({ err })
   }
 }
 
@@ -812,8 +832,15 @@ export async function calculateDocumentSelectors(
   config: ConfigEntry,
   features: Feature[],
   resolver: Resolver,
+  session?: OxideSession,
   actualConfig?: any,
 ) {
+  let hasTemporarySession = false
+  if (!session) {
+    hasTemporarySession = true
+    session = new OxideSession()
+  }
+
   let selectors: DocumentSelector[] = []
 
   // selectors:
@@ -834,7 +861,13 @@ export async function calculateDocumentSelectors(
   })
 
   // - Content patterns from config
-  for await (let selector of contentSelectorsFromConfig(config, features, resolver, actualConfig)) {
+  for await (let selector of contentSelectorsFromConfig(
+    config,
+    features,
+    resolver,
+    session,
+    actualConfig,
+  )) {
     selectors.push(selector)
   }
 
@@ -876,5 +909,9 @@ export async function calculateDocumentSelectors(
     return 0
   })
 
+  if (hasTemporarySession) {
+    await session.stop()
+  }
+
   return selectors
 }

packages/tailwindcss-language-server/src/projects.ts

@@ -964,6 +964,7 @@ export async function createProjectService(
         projectConfig.config,
         state.features,
         resolver,
+        undefined,
         originalConfig,
       )
     }