From 08e893528cafbf9a8cf99d418a0f2c1a16c3afef Mon Sep 17 00:00:00 2001
From: Roman Shevchenko <roman.shevchenko@jetbrains.com>
Date: Thu, 8 Dec 2011 17:55:46 +0100
Subject: [PATCH] [davdeev] Symlink support reloaded

---
 .../vfs/newvfs/impl/SymlinkDirectory.java     | 68 ++++++++++++++++---
 .../vfs/newvfs/impl/VirtualDirectoryImpl.java |  4 +-
 2 files changed, 60 insertions(+), 12 deletions(-)

diff --git a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/SymlinkDirectory.java b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/SymlinkDirectory.java
index 28dfa5d2226e..dc12c2d4b485 100644
--- a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/SymlinkDirectory.java
+++ b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/SymlinkDirectory.java
@@ -15,9 +15,11 @@
  */
 package com.intellij.openapi.vfs.newvfs.impl;
 
+import com.intellij.openapi.util.AtomicNotNullLazyValue;
 import com.intellij.openapi.util.NullableComputable;
 import com.intellij.openapi.util.RecursionManager;
 import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.openapi.vfs.newvfs.NewVirtualFile;
 import com.intellij.openapi.vfs.newvfs.NewVirtualFileSystem;
 import com.intellij.openapi.vfs.newvfs.VfsImplUtil;
 import org.jetbrains.annotations.NotNull;
@@ -25,28 +27,72 @@ import org.jetbrains.annotations.Nullable;
 
 /**
  * @author Dmitry Avdeev
- *         Date: 10/31/11
+ * @since 31.10.2011
  */
+@SuppressWarnings("NonSynchronizedMethodOverridesSynchronizedMethod")
 public class SymlinkDirectory extends VirtualDirectoryImpl {
+  private final AtomicNotNullLazyValue<VirtualDirectoryImpl> myTarget = new AtomicNotNullLazyValue<VirtualDirectoryImpl>() {
+    @NotNull
+    @Override
+    protected VirtualDirectoryImpl compute() {
+      final String path = getFileSystem().resolveSymLink(SymlinkDirectory.this);
+      VirtualFile file = null;
+      if (path != null)  {
+        file = findFile(path, false);
+      }
+      if (file == SymlinkDirectory.this && file != null) {
+        final VirtualFile parent = file.getParent();
+        if (parent instanceof VirtualDirectoryImpl) {
+          ((VirtualDirectoryImpl)parent).removeChild(file);
+          file = findFile(path, true);
+        }
+      }
+      return file instanceof VirtualDirectoryImpl ? (VirtualDirectoryImpl)file : new VirtualDirectoryImpl("foo", SymlinkDirectory.this, getFileSystem(), 0);
+    }
 
-  @Nullable
-  private final VirtualFile myTarget;
+    @Nullable
+    private VirtualFile findFile(final String path, final boolean refresh) {
+      return RecursionManager.doPreventingRecursion(SymlinkDirectory.this, false, new NullableComputable<VirtualFile>() {
+        @Override
+        public VirtualFile compute() {
+          return refresh ? VfsImplUtil.refreshAndFindFileByPath(getFileSystem(), path) : VfsImplUtil.findFileByPath(getFileSystem(), path);
+        }
+      });
+    }
+  };
 
   public SymlinkDirectory(@NotNull String name, final VirtualDirectoryImpl parent, @NotNull final NewVirtualFileSystem fs, final int id) {
     super(name, parent, fs, id);
-    final String path = fs.resolveSymLink(this);
+  }
 
-    myTarget = path == null ? null : RecursionManager.doPreventingRecursion("", false, new NullableComputable<VirtualFile>() {
-      @Override
-      public VirtualFile compute() {
-        return VfsImplUtil.findFileByPath(getFileSystem(), path);
-      }
-    });
+  @Override
+  public VirtualFileSystemEntry findChild(@NotNull String name) {
+    return myTarget.getValue().findChild(name);
+  }
+
+  @Override
+  public NewVirtualFile findChildIfCached(@NotNull String name) {
+    return myTarget.getValue().findChildIfCached(name);
+  }
+
+  @Override
+  public NewVirtualFile findChildById(int id) {
+    return myTarget.getValue().findChildById(id);
+  }
+
+  @Override
+  public NewVirtualFile findChildByIdIfCached(int id) {
+    return myTarget.getValue().findChildByIdIfCached(id);
+  }
+
+  @Override
+  public NewVirtualFile refreshAndFindChild(@NotNull String name) {
+    return myTarget.getValue().refreshAndFindChild(name);
   }
 
   @NotNull
   @Override
   public VirtualFile[] getChildren() {
-    return myTarget == null ? VirtualFile.EMPTY_ARRAY : myTarget.getChildren();
+    return myTarget.getValue().getChildren();
   }
 }
diff --git a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VirtualDirectoryImpl.java b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VirtualDirectoryImpl.java
index 1f2a85384360..128963c96843 100644
--- a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VirtualDirectoryImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VirtualDirectoryImpl.java
@@ -63,6 +63,8 @@ import java.util.*;
  * @author max
  */
 public class VirtualDirectoryImpl extends VirtualFileSystemEntry {
+  private static final boolean ALT_SYMLINK_HANDLING = "true".equals(System.getProperty("idea.io.alt.symlink"));
+
   private static final VirtualFileSystemEntry NULL_VIRTUAL_FILE = new VirtualFileImpl("*?;%NULL", null, -42);
 
   private final NewVirtualFileSystem myFS;
@@ -165,7 +167,7 @@ public class VirtualDirectoryImpl extends VirtualFileSystemEntry {
     final VirtualFileSystemEntry child;
     final NewVirtualFileSystem fs = getFileSystem();
     if (PersistentFS.isDirectory(id)) {
-      child = /*PersistentFS.isSymLink(id) ? new SymlinkDirectory(name, this, fs, id) :*/ new VirtualDirectoryImpl(name, this, fs, id);
+      child = ALT_SYMLINK_HANDLING && PersistentFS.isSymLink(id) ? new SymlinkDirectory(name, this, fs, id) : new VirtualDirectoryImpl(name, this, fs, id);
     }
     else {
       child = new VirtualFileImpl(name, this, id);