IJPL-161551 IjentNioFsPath + BasicFileAttributesHolder: fetch file attributes only when it is explicitly requested

GitOrigin-RevId: 5209a3af25fe96b6c694fcb651ff5789913be9a8

platform/core-nio-fs/src/com/intellij/platform/core/nio/fs/BasicFileAttributesHolder2.java

@@ -6,10 +6,14 @@ import org.jetbrains.annotations.Nullable;
 import sun.nio.fs.BasicFileAttributesHolder;
 
 import java.lang.ref.WeakReference;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Path;
 import java.nio.file.attribute.BasicFileAttributes;
 
 /**
  * This interface allows not adding `--add-exports` to modules where some class implements {@link BasicFileAttributesHolder}.
+ *
+ * Also, this interface defines some hacks and helper methods related to {@link BasicFileAttributesHolder}.
  */
 public interface BasicFileAttributesHolder2 extends BasicFileAttributesHolder {
   /**
@@ -47,4 +51,30 @@ public interface BasicFileAttributesHolder2 extends BasicFileAttributesHolder {
       myCachedAttributes.clear();
     }
   }
+
+  static @Nullable BasicFileAttributes getAttributesFromHolder(@NotNull Path path) {
+    if (path instanceof BasicFileAttributesHolder bafh) {
+      return bafh.get();
+    }
+    return null;
+  }
+
+  /**
+   * A marker interface for {@link java.nio.file.spi.FileSystemProvider#newDirectoryStream}
+   * that advises the file system to fetch file attributes and fill {@link BasicFileAttributesHolder}, if it's supported.
+   * <p>
+   * Unlike many other methods in {@code FileSystemProvider}, {@code newDirectoryStream} doesn't accept a set of options.
+   * The easiest way to provide additional information to the method is through the filter argument.
+   * </p>
+   * A file system provider should support this feature explicitly.
+   * This interface has no effect on default filesystems from JDK:
+   * <ul>
+   *   <li>In the default file system on Windows, file attributes are always fetched, regardless of the filter argument.</li>
+   *   <li>In the default file system on Posix, file attributes are never fetched.</li>
+   * </ul>
+   */
+  @FunctionalInterface
+  interface FetchAttributesFilter extends DirectoryStream.Filter<Path> {
+    FetchAttributesFilter ACCEPT_ALL = path -> true;
+  }
 }

platform/ijent/impl/src/com/intellij/platform/ijent/community/impl/nio/IjentNioFileSystemProvider.kt

@@ -2,6 +2,7 @@
 package com.intellij.platform.ijent.community.impl.nio
 
 import com.intellij.openapi.diagnostic.thisLogger
+import com.intellij.platform.core.nio.fs.BasicFileAttributesHolder2.FetchAttributesFilter
 import com.intellij.platform.ijent.community.impl.IjentFsResultImpl
 import com.intellij.platform.ijent.community.impl.nio.IjentNioFileSystemProvider.Companion.newFileSystemMap
 import com.intellij.platform.ijent.community.impl.nio.IjentNioFileSystemProvider.UnixFilePermissionBranch.*
@@ -180,23 +181,34 @@ class IjentNioFileSystemProvider : FileSystemProvider() {
     val nioFs = dir.nioFs
 
     return fsBlocking {
-      val children = nioFs.ijentFs
-        .listDirectoryWithAttrs(ensurePathIsAbsolute(dir.ijentPath), IjentFileSystemApi.SymlinkPolicy.DO_NOT_RESOLVE)
-        .getOrThrowFileSystemException()
-
-      val nioPathList = children.asSequence()
-        .map { (childName, childStat) ->
-          val childIjentPath = dir.ijentPath.getChild(childName).getOrThrow()
-          val childAttrs = when (childStat) {
-            is IjentPosixFileInfo -> IjentNioPosixFileAttributes(childStat)
-            is IjentWindowsFileInfo -> TODO()
-          }
-          IjentNioPath(childIjentPath, nioFs, childAttrs)
+      val notFilteredPaths =
+        if (pathFilter is FetchAttributesFilter) {
+          nioFs.ijentFs
+            .listDirectoryWithAttrs(ensurePathIsAbsolute(dir.ijentPath), IjentFileSystemApi.SymlinkPolicy.DO_NOT_RESOLVE)
+            .getOrThrowFileSystemException()
+            .asSequence()
+            .map { (childName, childStat) ->
+              val childIjentPath = dir.ijentPath.getChild(childName).getOrThrow()
+              val childAttrs = when (childStat) {
+                is IjentPosixFileInfo -> IjentNioPosixFileAttributes(childStat)
+                is IjentWindowsFileInfo -> TODO()
+              }
+              IjentNioPath(childIjentPath, nioFs, childAttrs)
+            }
         }
-        .filter { nioPath ->
-          pathFilter?.accept(nioPath) != false
+        else {
+          nioFs.ijentFs
+            .listDirectory(ensurePathIsAbsolute(dir.ijentPath))
+            .getOrThrowFileSystemException()
+            .asSequence()
+            .map { childName ->
+              val childIjentPath = dir.ijentPath.getChild(childName).getOrThrow()
+              IjentNioPath(childIjentPath, nioFs, null)
+            }
         }
-        .toMutableList()
+      val nioPathList = notFilteredPaths.filterTo(mutableListOf()) { nioPath ->
+        pathFilter?.accept(nioPath) != false
+      }
 
       object : DirectoryStream<Path> {
         // The compiler doesn't (didn't?) allow to relax types here.

platform/platform-impl/src/com/intellij/execution/wsl/ijent/nio/IjentWslNioFileSystemProvider.kt

@@ -6,6 +6,8 @@ import com.intellij.execution.wsl.WslPath
 import com.intellij.openapi.diagnostic.logger
 import com.intellij.openapi.util.io.CaseSensitivityAttribute
 import com.intellij.openapi.util.io.FileAttributes
+import com.intellij.platform.core.nio.fs.BasicFileAttributesHolder2
+import com.intellij.platform.core.nio.fs.BasicFileAttributesHolder2.FetchAttributesFilter
 import com.intellij.platform.core.nio.fs.RoutingAwareFileSystemProvider
 import com.intellij.platform.ijent.IjentPosixInfo
 import com.intellij.platform.ijent.community.impl.nio.IjentNioPath
@@ -315,11 +317,9 @@ class IjentWslNioFileSystemProvider(
           lastDirectory = lastDirectory.parent
         }
 
-        // TODO Add BasicFileAttributesHolder, it gives a huge speed up.
-        //val stat =
-        //  source.asSafely<BasicFileAttributesHolder>()?.get()
-        //  ?: source.readAttributes(LinkOption.NOFOLLOW_LINKS)
-        val stat = source.readAttributes<BasicFileAttributes>(LinkOption.NOFOLLOW_LINKS)
+        val stat =
+          BasicFileAttributesHolder2.getAttributesFromHolder(source)
+          ?: source.readAttributes(LinkOption.NOFOLLOW_LINKS)
 
         // WindowsPath doesn't support resolve() from paths of different class.
         val target = source.relativeTo(sourceRoot).fold(targetRoot) { parent, file ->
@@ -337,7 +337,7 @@ class IjentWslNioFileSystemProvider(
                 throw err
               }
             }
-            Files.newDirectoryStream(source).use { children ->
+            source.fileSystem.provider().newDirectoryStream(source, FetchAttributesFilter.ACCEPT_ALL).use { children ->
               sourceStack.addAll(children.toList().asReversed())
             }
           }

platform/platform-impl/src/com/intellij/util/io/PlatformNioHelper.java

@@ -2,6 +2,7 @@
 package com.intellij.util.io;
 
 import com.intellij.openapi.util.io.NioFiles;
+import com.intellij.platform.core.nio.fs.BasicFileAttributesHolder2.FetchAttributesFilter;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -40,7 +41,7 @@ public final class PlatformNioHelper {
   @SuppressWarnings({"UnnecessaryFullyQualifiedName", "InstanceofIncompatibleInterface"})
   public static void visitDirectory(@NotNull Path directory, @Nullable Set<String> filter, @NotNull BiPredicate<Path, Result<BasicFileAttributes>> consumer)
   throws IOException, SecurityException {
-    try (var dirStream = Files.newDirectoryStream(directory)) {
+    try (var dirStream = directory.getFileSystem().provider().newDirectoryStream(directory, FetchAttributesFilter.ACCEPT_ALL)) {
       for (var path : dirStream) {
         if (filter != null && !filter.contains(path.getFileName().toString())) {
           continue;