IJPL-217737 IJent: Posix-to-DOS FileAttributeView adapter

GitOrigin-RevId: de5c63d4a310ba3ef225f3dfba70e7758f5d2b71

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

@@ -2,6 +2,7 @@
 package com.intellij.platform.ide.impl.wsl.ijent.nio
 
 import com.intellij.execution.ijent.nio.getCachedFileAttributesAndWrapToDosAttributesAdapter
+import com.intellij.execution.ijent.nio.getFileAttributeViewUsingDosAttributesAdapter
 import com.intellij.execution.ijent.nio.readAttributesUsingDosAttributesAdapter
 import com.intellij.execution.wsl.WslDistributionManager
 import com.intellij.execution.wsl.WslPath
@@ -302,8 +303,8 @@ class IjentWslNioFileSystemProvider(
   override fun getFileStore(path: Path): FileStore =
     ijentFsProvider.getFileStore(path.toIjentPath())
 
-  override fun <V : FileAttributeView?> getFileAttributeView(path: Path, type: Class<V>, vararg options: LinkOption): V =
-    ijentFsProvider.getFileAttributeView(path.toIjentPath(), type, *options)
+  override fun <V : FileAttributeView> getFileAttributeView(path: Path, type: Class<V>, vararg options: LinkOption): V =
+    ijentFsProvider.getFileAttributeViewUsingDosAttributesAdapter(path.toIjentPath(), type, *options)
 
   override fun <A : BasicFileAttributes> readAttributes(path: Path, type: Class<A>, vararg options: LinkOption): A {
     return ijentFsProvider.readAttributesUsingDosAttributesAdapter(path, path.toIjentPath(), type, *options)

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

@@ -12,9 +12,7 @@ import com.intellij.platform.ijent.community.impl.nio.IjentNioPosixFileAttribute
 import org.jetbrains.annotations.ApiStatus
 import java.nio.file.LinkOption
 import java.nio.file.Path
-import java.nio.file.attribute.BasicFileAttributes
-import java.nio.file.attribute.DosFileAttributes
-import java.nio.file.attribute.PosixFileAttributes
+import java.nio.file.attribute.*
 import java.nio.file.attribute.PosixFilePermission.*
 import java.nio.file.spi.FileSystemProvider
 import kotlin.io.path.name
@@ -111,4 +109,84 @@ class IjentNioPosixFileAttributesWithDosAdapter(
   override fun getCaseSensitivity(): FileAttributes.CaseSensitivity {
     if (fileInfo is CaseSensitivityAttribute) return fileInfo.caseSensitivity else return FileAttributes.CaseSensitivity.UNKNOWN
   }
+}
+
+@ApiStatus.Internal
+class IjentNioPosixFileAttributeViewWithDosAdapter(
+  private val userInfo: EelUserPosixInfo,
+  private val posixView: PosixFileAttributeView,
+  private val nameStartsWithDot: Boolean,
+) : PosixFileAttributeView by posixView, DosFileAttributeView {
+  override fun readAttributes(): IjentNioPosixFileAttributesWithDosAdapter =
+    IjentNioPosixFileAttributesWithDosAdapter(userInfo, posixView.readAttributes(), nameStartsWithDot)
+
+  override fun setReadOnly(readOnly: Boolean) {
+    val permissions: MutableSet<PosixFilePermission> = posixView.readAttributes().permissions()
+
+    // "Read-only" implies "readable", "not read-only" implies "not only readable". In any case, the resource is supposed to be readable.
+    permissions += OWNER_READ
+
+    if (readOnly) {
+      permissions -= OWNER_WRITE
+      permissions -= GROUP_WRITE
+      permissions -= OTHERS_WRITE
+    }
+    else {
+      // Windows has a complicated ACL for every file, but this option refers to the old DOS attribute.
+      // MS DOS was not a multi-user operating system, but Posix systems are.
+      // The dilemma is in how to treat the request to setting the read-only attribute as false:
+      // make the file readable for everyone or only for the owner.
+      // This code explicitly sets only for the user because in the worst but rare scenario it leads to non-functioning features,
+      // but too broad permissions can hypothetically lead to a security issue.
+      permissions += OWNER_WRITE
+    }
+
+    posixView.setPermissions(permissions)
+  }
+
+  override fun setHidden(value: Boolean) {
+    // There's no such conception as a hidden file in terms of the Posix filesystem,
+    // but there's a tradition to treat all files starting from `.` as hidden.
+    //
+    // File renaming is certainly something that the caller of `DosFileAttribute.setHidden` does not expect.
+    // Throwing an error might have been possible if this implementation was introduced for new code,
+    // but it is here to support unknown legacy code.
+    //
+    // Lastly, it might be worth using extended attributes like `sun.nio.fs.LinuxDosFileAttributeView` does,
+    // but it's usually unexpected, it's not supported on macOS, and also it requires efforts for implementing.
+    // Reference: https://github.com/JetBrains/JetBrainsRuntime/blob/922b12f30c4cfd6b504d66daf37fb30c7fb1bfe7/src/java.base/linux/classes/sun/nio/fs/LinuxDosFileAttributeView.java
+    //
+    // Thus, it's better to do nothing in this method.
+  }
+
+  override fun setSystem(value: Boolean) {
+    // There's no such conception as a "system file" in Posix, though it might be implemented like in `sun.nio.fs.LinuxDosFileAttributeView`
+  }
+
+  override fun setArchive(value: Boolean) {
+    // There's no such conception as a "system file" in Posix, though it might be implemented like in `sun.nio.fs.LinuxDosFileAttributeView`
+  }
+}
+
+@ApiStatus.Internal
+fun <V : FileAttributeView> FileSystemProvider.getFileAttributeViewUsingDosAttributesAdapter(
+  ijentPath: IjentNioPath,
+  type: Class<V>,
+  vararg options: LinkOption,
+): V {
+  val actualType = when {
+    DosFileAttributeView::class.java.isAssignableFrom(type) -> PosixFileAttributeView::class.java
+    else -> type
+  }
+
+  val resultAttrs = when (val actualView = getFileAttributeView(ijentPath, actualType, *options)) {
+    is PosixFileAttributeView -> IjentNioPosixFileAttributeViewWithDosAdapter(
+      userInfo = ijentPath.fileSystem.ijentFs.user as EelUserPosixInfo,
+      posixView = actualView,
+      nameStartsWithDot = ijentPath.name.startsWith("."),
+    )
+    else -> actualView
+  }
+
+  return type.cast(resultAttrs)
 }