From 3446144f9683bec9ad4f32b3f40170afb9fcb69b Mon Sep 17 00:00:00 2001
From: Bernd Eckenfels <b.eckenfels@seeburger.de>
Date: Fri, 24 May 2024 13:24:47 +0200
Subject: [PATCH] Avoid piling up FileListener during GC

This short-cuts getting the URIs for Collected files.
DarcBasicTest.testCollectBlobs ensures result is unchanged.
---
 .../digestarc/DarcFileCollectOperation.java   | 29 ++++++++++---------
 .../provider/digestarc/DarcFileObject.java    | 22 ++++++++++++++
 2 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileCollectOperation.java b/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileCollectOperation.java
index 3ff1960..32e870e 100644
--- a/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileCollectOperation.java
+++ b/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileCollectOperation.java
@@ -48,25 +48,26 @@ public DarcFileCollectOperation(FileObject root)
     public void process()
         throws FileSystemException
     {
-        if (root instanceof DarcFileObject)
+        if (!(root instanceof DarcFileObject))
         {
-            DarcFileObject darcFile = (DarcFileObject) root;
-            FileObject delegateFile = darcFile.getDelegateFile();
+            return;
+        }
 
-            filesList.add(delegateFile.getName().getURI());
+        final DarcFileObject darcFile = (DarcFileObject) root;
+        final String uri = darcFile.getDelegateURI();
+        filesList.add(uri);
 
-            if (darcFile.getType() == FileType.FOLDER)
+        if (darcFile.getType() == FileType.FOLDER)
+        {
+            FileObject[] fileList = darcFile.getChildren();
+            for (FileObject nextFile : fileList)
             {
-                FileObject[] fileList = darcFile.getChildren();
-                for (FileObject nextFile : fileList)
+                FileOperations fileOperations = nextFile.getFileOperations();
+                CollectFilesOperation operation = (CollectFilesOperation) fileOperations.getOperation(CollectFilesOperation.class);
+                if (operation != null)
                 {
-                    FileOperations fileOperations = nextFile.getFileOperations();
-                    CollectFilesOperation operation = (CollectFilesOperation) fileOperations.getOperation(CollectFilesOperation.class);
-                    if (operation != null)
-                    {
-                        operation.setFilesList(filesList);
-                        operation.process();
-                    }
+                    operation.setFilesList(filesList);
+                    operation.process();
                 }
             }
         }
diff --git a/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileObject.java b/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileObject.java
index 21b3916..5f0c37b 100644
--- a/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileObject.java
+++ b/vfs2provider-digestarc/src/main/java/com/seeburger/vfs2/provider/digestarc/DarcFileObject.java
@@ -372,6 +372,28 @@ public void fileChanged(FileChangeEvent event)
         }
     }
 
+
+    /**
+     * Used by DarcFileCollectOperation to get URI of delegate.
+     * <P>
+     * This is done to avoid listener registration in {@link #getDelegateFile()}.
+     *
+     * @throws FileSystemException if lower level miss-behaves
+     */
+    protected String getDelegateURI() throws FileSystemException
+    {
+        Entry entry = getEntry();
+        String hash = entry.getHash();
+        FileObject targetFile = getProvider().resolveFileHash(hash);
+        if (targetFile != null)
+        {
+            /* we could refresh target here */
+            return targetFile.getName().getURI();
+        }
+        throw new FileSystemException("Expected file blob with hash=" + hash + " cannot be resolved");
+    }
+
+
     private BlobStorageProvider getProvider()
     {
         return ((DarcFileSystem)getFileSystem()).getBlobProvider();