[importers] Also speed up koreader imports

vrobbler/apps/scrobbles/importers/webdav.py

@@ -71,10 +71,14 @@ def import_from_webdav_for_all_users(restart=False, update_retroarch_hash=False)
 
 
 def scan_webdav_for_koreader(webdav_client, user_id, restart=False):
-    """Check for koreader statistics.sqlite3 and queue import if changed."""
+    """Check for koreader statistics.sqlite3 and queue import if changed.
+
+    Uses the remote file's ETag (from a single PROPFIND) to detect changes
+    without downloading the file, making the common no-change case fast.
+    """
     koreader_path = DEFAULT_KOREADER_PATH + "statistics.sqlite3"
     try:
-        webdav_client.info(koreader_path)
+        remote_info = webdav_client.info(koreader_path)
     except:
         logger.info(
             "No koreader stats file found on webdav",
@@ -82,12 +86,26 @@ def scan_webdav_for_koreader(webdav_client, user_id, restart=False):
         )
         return 0
 
+    remote_etag = remote_info.get("etag") or ""
+
     last_import = (
         KoReaderImport.objects.filter(user_id=user_id, processed_finished__isnull=False)
         .order_by("processed_finished")
         .last()
     )
 
+    if last_import and last_import.webdav_etag and remote_etag:
+        if last_import.webdav_etag == remote_etag:
+            logger.info(
+                "koreader stats file unchanged (ETag match)",
+                extra={
+                    "user_id": user_id,
+                    "etag": remote_etag,
+                    "last_import_id": last_import.id,
+                },
+            )
+            return 0
+
     file_path = fetch_file_from_webdav(user_id)
     if not file_path:
         logger.warning(
@@ -99,9 +117,9 @@ def scan_webdav_for_koreader(webdav_client, user_id, restart=False):
     new_hash = get_file_md5_hash(file_path)
     old_hash = last_import.file_md5_hash() if last_import else None
 
-    if last_import and new_hash == old_hash:
+    if last_import and remote_etag and new_hash == old_hash:
         logger.info(
-            "koreader stats file has not changed",
+            "koreader stats file has not changed (content hash match)",
             extra={
                 "user_id": user_id,
                 "new_hash": new_hash,
@@ -124,6 +142,7 @@ def scan_webdav_for_koreader(webdav_client, user_id, restart=False):
         os.unlink(file_path)
         return 0
 
+    koreader_import.webdav_etag = remote_etag
     koreader_import.save_sqlite_file_to_self(file_path)
     process_koreader_import.delay(koreader_import.id)
     os.unlink(file_path)
@@ -219,8 +238,8 @@ def scan_webdav_for_retroarch(webdav_client, user_id, update_hash_only=False):
         return 0
 
     lrtl_files = sorted(
-        [f for f in files if f.get("name", "").lower().endswith(".lrtl")],
-        key=lambda x: x.get("name", ""),
+        [f for f in files if (f.get("name") or "").lower().endswith(".lrtl")],
+        key=lambda x: (x.get("name") or ""),
     )
     if not lrtl_files:
         logger.info("No .lrtl files found on webdav", extra={"user_id": user_id})
@@ -239,7 +258,7 @@ def scan_webdav_for_retroarch(webdav_client, user_id, update_hash_only=False):
     # Compute hash from filenames + ETags (no downloads needed)
     hasher = hashlib.md5()
     for f in lrtl_files:
-        hasher.update(f.get("name", "").encode())
+        hasher.update((f.get("name") or "").encode())
         hasher.update((f.get("etag") or f.get("modified") or "").encode())
     content_hash = hasher.hexdigest()
 

vrobbler/apps/scrobbles/migrations/0087_koreaderimport_webdav_etag.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.2.29 on 2026-05-26 13:15
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("scrobbles", "0086_add_import_in_progress_to_lastfmimport"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="koreaderimport",
+            name="webdav_etag",
+            field=models.CharField(blank=True, max_length=255, null=True),
+        ),
+    ]

vrobbler/apps/scrobbles/models.py

@@ -188,6 +188,7 @@ class KoReaderImport(BaseFileImportMixin):
         return path
 
     sqlite_file = models.FileField(upload_to=get_path, **BNULL)
+    webdav_etag = models.CharField(max_length=255, **BNULL)
 
     def save_sqlite_file_to_self(self, file_path):
         with open(file_path, "rb") as f: