From bde25e49adce008cd4479653ba6af364a16410d0 Mon Sep 17 00:00:00 2001
From: Andrii Zinchenko <andrii.zinchenko@jetbrains.com>
Date: Thu, 26 Jun 2025 16:53:23 +0200
Subject: [PATCH] [platform-eel] IJPL-194035: All IJent filesystems are loaded
 greedily by recent projects in Welcome Screen

(cherry picked from commit 7868f0266f728dbbca0666c600e5964a1d4282e5)


(cherry picked from commit 4d3ec53a85d91ddb66a547edfea28c39157cb4c5)

IJ-MR-167682

GitOrigin-RevId: 96b3ebfbcfe9642a6010fd9b7726ca17742ac03d
---
 .../impl/IjentFailSafeFileSystemPosixApi.kt   | 19 +++++++------------
 .../nio/toggle/IjentWslNioFsToggleStrategy.kt |  6 ++----
 .../intellij/ide/RecentProjectIconHelper.kt   | 11 +++++++++++
 .../intellij/ide/RecentProjectsManagerBase.kt | 11 +++++++++++
 .../repo/GitRecentProjectsBranchesProvider.kt | 10 ++++++++++
 5 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/platform/ijent/impl/src/com/intellij/platform/ijent/community/impl/IjentFailSafeFileSystemPosixApi.kt b/platform/ijent/impl/src/com/intellij/platform/ijent/community/impl/IjentFailSafeFileSystemPosixApi.kt
index bf5796759391..03187550958f 100644
--- a/platform/ijent/impl/src/com/intellij/platform/ijent/community/impl/IjentFailSafeFileSystemPosixApi.kt
+++ b/platform/ijent/impl/src/com/intellij/platform/ijent/community/impl/IjentFailSafeFileSystemPosixApi.kt
@@ -38,15 +38,15 @@ import java.util.concurrent.atomic.AtomicReference
 @Suppress("FunctionName")
 fun IjentFailSafeFileSystemPosixApi(
   coroutineScope: CoroutineScope,
-  delegateFactory: suspend () -> IjentPosixApi,
+  descriptor: EelDescriptor,
 ): IjentFileSystemApi {
-  val holder = DelegateHolder<IjentPosixApi, IjentFileSystemPosixApi>(coroutineScope, delegateFactory)
-  return IjentFailSafeFileSystemPosixApiImpl(holder)
+  val holder = DelegateHolder<IjentPosixApi, IjentFileSystemPosixApi>(coroutineScope, descriptor)
+  return IjentFailSafeFileSystemPosixApiImpl(holder, descriptor)
 }
 
 private class DelegateHolder<I : IjentApi, F : IjentFileSystemApi>(
   private val coroutineScope: CoroutineScope,
-  private val delegateFactory: suspend () -> I,
+  private val descriptor: EelDescriptor
 ) {
   private val delegate = AtomicReference<Deferred<I>?>(null)
 
@@ -63,7 +63,8 @@ private class DelegateHolder<I : IjentApi, F : IjentFileSystemApi>(
         oldDelegate
       else
         coroutineScope.async(Dispatchers.IO, start = CoroutineStart.LAZY) {
-          delegateFactory()
+          @Suppress("UNCHECKED_CAST")
+          descriptor.toEelApi() as I
         }
     }!!
 
@@ -100,6 +101,7 @@ private class DelegateHolder<I : IjentApi, F : IjentFileSystemApi>(
  */
 private class IjentFailSafeFileSystemPosixApiImpl(
   private val holder: DelegateHolder<IjentPosixApi, IjentFileSystemPosixApi>,
+  override val descriptor: EelDescriptor
 ) : IjentFileSystemPosixApi {
   // TODO Make user suspendable again?
   override val user: EelUserPosixInfo by lazy {
@@ -108,13 +110,6 @@ private class IjentFailSafeFileSystemPosixApiImpl(
     }
   }
 
-  override val descriptor: EelDescriptor by lazy {
-    runBlocking {
-      holder.withDelegateRetrying { descriptor }
-    }
-  }
-
-
   override suspend fun listDirectory(
     path: EelPath,
   ): EelResult<Collection<String>, EelFileSystemApi.ListDirectoryError> =
diff --git a/platform/platform-impl/eel/src/com/intellij/platform/ide/impl/wsl/ijent/nio/toggle/IjentWslNioFsToggleStrategy.kt b/platform/platform-impl/eel/src/com/intellij/platform/ide/impl/wsl/ijent/nio/toggle/IjentWslNioFsToggleStrategy.kt
index a79b84fa22b2..8dbcb497f605 100644
--- a/platform/platform-impl/eel/src/com/intellij/platform/ide/impl/wsl/ijent/nio/toggle/IjentWslNioFsToggleStrategy.kt
+++ b/platform/platform-impl/eel/src/com/intellij/platform/ide/impl/wsl/ijent/nio/toggle/IjentWslNioFsToggleStrategy.kt
@@ -3,7 +3,6 @@ package com.intellij.platform.ide.impl.wsl.ijent.nio.toggle
 
 import com.intellij.execution.wsl.WSLDistribution
 import com.intellij.execution.wsl.WslDistributionManager
-import com.intellij.execution.wsl.WslIjentManager
 import com.intellij.openapi.diagnostic.logger
 import com.intellij.platform.eel.provider.EelNioBridgeService
 import com.intellij.platform.ide.impl.wsl.ijent.nio.IjentWslNioFileSystemProvider
@@ -74,9 +73,8 @@ class IjentWslNioFsToggleStrategy(
   fun switchToIjentFs(distro: WSLDistribution) {
     val ijentFsProvider = TracingFileSystemProvider(IjentNioFileSystemProvider.getInstance())
     try {
-      val ijentFs = IjentFailSafeFileSystemPosixApi(coroutineScope) {
-        WslIjentManager.instanceAsync().getIjentApi(distro, null, false)
-      }
+      val distributionId = distro.id
+      val ijentFs = IjentFailSafeFileSystemPosixApi(coroutineScope, WslEelDescriptor(WSLDistribution(distributionId)))
       ijentFsProvider.newFileSystem(
         URI("ijent", "wsl", "/${distro.id}", null, null),
         IjentNioFileSystemProvider.newFileSystemMap(ijentFs),
diff --git a/platform/platform-impl/src/com/intellij/ide/RecentProjectIconHelper.kt b/platform/platform-impl/src/com/intellij/ide/RecentProjectIconHelper.kt
index db6e50000fc3..7eb861eec753 100644
--- a/platform/platform-impl/src/com/intellij/ide/RecentProjectIconHelper.kt
+++ b/platform/platform-impl/src/com/intellij/ide/RecentProjectIconHelper.kt
@@ -7,6 +7,8 @@ import com.intellij.openapi.diagnostic.logger
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.project.ProjectStorePathManager
 import com.intellij.openapi.util.registry.Registry
+import com.intellij.platform.eel.provider.LocalEelDescriptor
+import com.intellij.platform.eel.provider.getEelDescriptor
 import com.intellij.ui.IconDeferrer
 import com.intellij.ui.JBColor
 import com.intellij.ui.LayeredIcon
@@ -34,6 +36,7 @@ import java.nio.file.attribute.BasicFileAttributes
 import java.util.*
 import java.util.concurrent.atomic.AtomicInteger
 import javax.swing.Icon
+import kotlin.io.path.Path
 
 @Internal
 fun unscaledProjectIconSize(): Int = Registry.intValue("ide.project.icon.size", 20)
@@ -216,6 +219,14 @@ private fun getCustomIconFileInfo(path: @SystemIndependent String): Pair<Path, B
 }
 
 private fun getCustomIcon(path: @SystemIndependent String, isProjectValid: Boolean, iconSize: Int): Icon? {
+  // IJPL-194035
+  // Avoid greedy I/O under non-local projects. For example, in the case of WSL:
+  //	1.	it may trigger Ijent initialization for each recent project
+  //	2.	with Ijent disabled, performance may degrade further — 9P is very slow and could lead to UI freezes
+  if (Path(path).getEelDescriptor() != LocalEelDescriptor) {
+    return null
+  }
+
   val (file, fileInfo) = getCustomIconFileInfo(path) ?: return null
   val timestamp = fileInfo.lastModifiedTime().toMillis()
 
diff --git a/platform/platform-impl/src/com/intellij/ide/RecentProjectsManagerBase.kt b/platform/platform-impl/src/com/intellij/ide/RecentProjectsManagerBase.kt
index a7e683c142ca..197ab36cdab1 100644
--- a/platform/platform-impl/src/com/intellij/ide/RecentProjectsManagerBase.kt
+++ b/platform/platform-impl/src/com/intellij/ide/RecentProjectsManagerBase.kt
@@ -43,6 +43,8 @@ import com.intellij.openapi.wm.impl.*
 import com.intellij.openapi.wm.impl.customFrameDecorations.header.CustomWindowHeaderUtil
 import com.intellij.platform.diagnostic.telemetry.impl.span
 import com.intellij.platform.eel.provider.EelInitialization
+import com.intellij.platform.eel.provider.LocalEelDescriptor
+import com.intellij.platform.eel.provider.getEelDescriptor
 import com.intellij.platform.ide.diagnostic.startUpPerformanceReporter.FUSProjectHotStartUpMeasurer
 import com.intellij.project.stateStore
 import com.intellij.ui.mac.createMacDelegate
@@ -71,6 +73,7 @@ import java.util.concurrent.atomic.LongAdder
 import javax.swing.Icon
 import javax.swing.JFrame
 import kotlin.collections.Map.Entry
+import kotlin.io.path.Path
 import kotlin.io.path.exists
 import kotlin.io.path.invariantSeparatorsPathString
 import kotlin.io.path.relativeTo
@@ -953,6 +956,14 @@ private fun readProjectName(path: String): String {
     return path
   }
 
+  // IJPL-194035
+  // Avoid greedy I/O under non-local projects. For example, in the case of WSL:
+  //	1.	it may trigger Ijent initialization for each recent project
+  //	2.	with Ijent disabled, performance may degrade further — 9P is very slow and could lead to UI freezes
+  if (Path(path).getEelDescriptor() != LocalEelDescriptor) {
+    return path
+  }
+
   if (path.endsWith(".ipr")) {
     return FileUtilRt.getNameWithoutExtension(path)
   }
diff --git a/plugins/git4idea/src/git4idea/repo/GitRecentProjectsBranchesProvider.kt b/plugins/git4idea/src/git4idea/repo/GitRecentProjectsBranchesProvider.kt
index 1cca7b4e7bab..1a1f519bce00 100644
--- a/plugins/git4idea/src/git4idea/repo/GitRecentProjectsBranchesProvider.kt
+++ b/plugins/git4idea/src/git4idea/repo/GitRecentProjectsBranchesProvider.kt
@@ -13,6 +13,8 @@ import com.intellij.openapi.components.service
 import com.intellij.openapi.diagnostic.thisLogger
 import com.intellij.openapi.options.advanced.AdvancedSettings
 import com.intellij.openapi.wm.IdeFrame
+import com.intellij.platform.eel.provider.LocalEelDescriptor
+import com.intellij.platform.eel.provider.getEelDescriptor
 import com.intellij.util.application
 import git4idea.GitUtil
 import git4idea.branch.GitBranchUtil
@@ -93,6 +95,14 @@ internal class GitRecentProjectsBranchesService(val coroutineScope: CoroutineSco
     if (!showBranchMode.shouldShow(nameIsDistinct)) {
       return null
     }
+
+    // IJPL-194035
+    // Avoid greedy I/O under non-local projects. For example, in the case of WSL:
+    //	1.	it may trigger Ijent initialization for each recent project
+    //	2.	with Ijent disabled, performance may degrade further — 9P is very slow and could lead to UI freezes
+    if (Path(projectPath).getEelDescriptor() != LocalEelDescriptor) {
+      return null
+    }
     val branchFuture = cache.get(projectPath)
     return (branchFuture.getNow(GitRecentProjectCachedBranch.Unknown) as? GitRecentProjectCachedBranch.KnownBranch)?.branchName
   }