From 3bbfb0d19722fdac2f827deebc0030ce7a1f7291 Mon Sep 17 00:00:00 2001
From: wolpi <wolpi.dev@web.de>
Date: Sat, 19 Oct 2024 14:05:48 +0200
Subject: [PATCH] More usage of URI-base-SAF-API (instead of DocumentFile) in
 SAF to avoid calls to listFiles() which is very slow, but use cursor to list
 children, see GH issues #372 and #376

---
 .../org/primftpd/filesystem/RoSafFile.java    |  1 +
 .../src/org/primftpd/filesystem/SafFile.java  | 63 ++++++++++++++++---
 .../filesystem/SafFileSystemView.java         |  4 ++
 3 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/primitiveFTPd/src/org/primftpd/filesystem/RoSafFile.java b/primitiveFTPd/src/org/primftpd/filesystem/RoSafFile.java
index 4153ccfe..2c70a15b 100644
--- a/primitiveFTPd/src/org/primftpd/filesystem/RoSafFile.java
+++ b/primitiveFTPd/src/org/primftpd/filesystem/RoSafFile.java
@@ -26,6 +26,7 @@ public abstract class RoSafFile<TMina, TFileSystemView extends RoSafFileSystemVi
     private boolean writable;
     private boolean deletable;
 
+    static final int CURSOR_INDEX_ID = 0;
     static final int CURSOR_INDEX_NAME = 1;
     static final String[] SAF_QUERY_COLUMNS = {
             DocumentsContract.Document.COLUMN_DOCUMENT_ID,
diff --git a/primitiveFTPd/src/org/primftpd/filesystem/SafFile.java b/primitiveFTPd/src/org/primftpd/filesystem/SafFile.java
index c451b87e..8ad24d79 100644
--- a/primitiveFTPd/src/org/primftpd/filesystem/SafFile.java
+++ b/primitiveFTPd/src/org/primftpd/filesystem/SafFile.java
@@ -1,7 +1,10 @@
 package org.primftpd.filesystem;
 
+import android.content.Context;
+import android.database.Cursor;
 import android.net.Uri;
 import android.os.Build;
+import android.provider.DocumentsContract;
 import android.widget.Toast;
 
 import org.primftpd.events.ClientActionEvent;
@@ -80,6 +83,10 @@ public SafFile(
         this.parentNonexistentDirs = parentNonexistentDirs;
     }
 
+    protected final Uri getStartUrl() {
+        return getFileSystemView().getStartUrl();
+    }
+
     private boolean mkParentNonexistentDirs() {
         if (0 < parentNonexistentDirs.size()) {
             DocumentFile parentDoc = parentDocumentFile;
@@ -216,18 +223,60 @@ public List<TMina> listFiles() {
         logger.trace("[{}] listFiles()", name);
         postClientAction(ClientActionEvent.ClientAction.LIST_DIR);
 
-        DocumentFile[] children = documentFile.listFiles();
-        List<TMina> result = new ArrayList<>(children.length);
-        for (DocumentFile child : children) {
-            String absPath = this.absPath.endsWith("/")
-                    ? this.absPath + child.getName()
-                    : this.absPath + "/" + child.getName();
-            result.add(createFile(absPath, documentFile, child));
+        // listFiles() is very slow, use URI-based-SAF-API as in RoSAF instead
+//        DocumentFile[] children = documentFile.listFiles();
+//        List<TMina> result = new ArrayList<>(children.length);
+//        for (DocumentFile child : children) {
+//            String absPath = this.absPath.endsWith("/")
+//                    ? this.absPath + child.getName()
+//                    : this.absPath + "/" + child.getName();
+//            result.add(createFile(absPath, documentFile, child));
+//        }
+
+        List<TMina> result = new ArrayList<>();
+        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
+            Uri startUrl = getStartUrl();
+            Context context = getPftpdService().getContext();
+
+            Cursor childCursor = null;
+            try {
+                String documentId = DocumentsContract.getDocumentId(documentFile.getUri());
+                Uri childrenUri = DocumentsContract.buildChildDocumentsUriUsingTree(
+                        startUrl,
+                        documentId);
+                childCursor = context.getContentResolver().query(
+                        childrenUri,
+                        RoSafFile.SAF_QUERY_COLUMNS,
+                        null,
+                        null,
+                        null);
+                while (childCursor.moveToNext()) {
+                    String absPath = this.absPath.endsWith("/")
+                            ? this.absPath + childCursor.getString(RoSafFile.CURSOR_INDEX_NAME)
+                            : this.absPath + "/" + childCursor.getString(RoSafFile.CURSOR_INDEX_NAME);
+                    String childId = childCursor.getString(RoSafFile.CURSOR_INDEX_ID);
+                    Uri childUri = DocumentsContract.buildDocumentUriUsingTree(startUrl, childId);
+                    DocumentFile childDocFile = DocumentFile.fromTreeUri(context, childUri);
+                    result.add(createFile(absPath, documentFile, childDocFile));
+                }
+            } catch (Exception e) {
+                logger.error("", e);
+                Toast.makeText(context, e.getMessage(), Toast.LENGTH_SHORT).show();
+            } finally {
+                closeQuietly(childCursor);
+            }
         }
+
         logger.trace("  [{}] listFiles(): num children: {}", name, result.size());
         return result;
     }
 
+    private void closeQuietly(Cursor cursor) {
+        if (cursor != null) {
+            cursor.close();
+        }
+    }
+
     public OutputStream createOutputStream(long offset) throws IOException {
         logger.trace("[{}] createOutputStream(offset: {})", name, offset);
         postClientAction(ClientActionEvent.ClientAction.UPLOAD);
diff --git a/primitiveFTPd/src/org/primftpd/filesystem/SafFileSystemView.java b/primitiveFTPd/src/org/primftpd/filesystem/SafFileSystemView.java
index 7f2717ea..03470673 100644
--- a/primitiveFTPd/src/org/primftpd/filesystem/SafFileSystemView.java
+++ b/primitiveFTPd/src/org/primftpd/filesystem/SafFileSystemView.java
@@ -30,6 +30,10 @@ public SafFileSystemView(PftpdService pftpdService, Uri startUrl) {
         this.timeResolution = StorageManagerUtil.getFilesystemTimeResolutionForTreeUri(startUrl);
     }
 
+    public final Uri getStartUrl() {
+        return startUrl;
+    }
+
     protected abstract TFile createFile(
             String absPath,
             DocumentFile parentDocumentFile,