Fix consistency_checks for externally stored blobs

Author: alexdachin

apps/server/src/becca/entities/abstract_becca_entity.ts

@@ -230,7 +230,25 @@ abstract class AbstractBeccaEntity<T extends AbstractBeccaEntity<T>> {
         const blobNeedsInsert = !sql.getValue("SELECT 1 FROM blobs WHERE blobId = ?", [newBlobId]);
 
         if (!blobNeedsInsert) {
-            return newBlobId;
+            if (!blobStorageService.hasExternalContentColumns()) {
+                // If no external storage support, safe to reuse blob
+                return newBlobId;
+            }
+
+            // Self recover external blob if the file was deleted externally
+            const existingBlob = sql.getRow<{ contentLocation: BlobContentLocation }>(/*sql*/
+                `SELECT contentLocation FROM blobs WHERE blobId = ?`,
+                [newBlobId]
+            );
+
+            const isInternalBlob = existingBlob?.contentLocation === 'internal';
+            if (isInternalBlob || blobStorageService.externalFileExists(existingBlob.contentLocation)) {
+                // If external blob is still present, safe to reuse
+                return newBlobId;
+            }
+
+            // External file is missing, recreate it
+            log.info(`External file missing for blob ${newBlobId}, recreating...`);
         }
 
         // Check if we should store this blob externally

apps/server/src/services/blob-storage.ts

@@ -23,7 +23,7 @@ export class BlobStorageService {
     /**
      * Check if the external content columns (contentLocation, contentLength) exist in the blobs table.
      * This is cached for performance.
-     * Returns false before migration 234 has been applied (for example when applying older migrations).
+     * Returns false before migration 234 has been applied (aka when applying older migrations).
      */
     hasExternalContentColumns(): boolean {
         if (!this._hasExternalContentColumns) {
@@ -123,6 +123,19 @@ export class BlobStorageService {
 
         return blob.getContentLength(content) > config.ExternalBlobStorage.thresholdBytes;
     }
+
+    /**
+     * Check if an external blob file exists
+     */
+    externalFileExists(contentLocation: BlobContentLocation): boolean {
+        if (contentLocation === "internal" || !contentLocation.startsWith("file://")) {
+            return false;
+        }
+
+        const relativePath = contentLocation.replace("file://", "");
+        const filePath = path.join(this.externalBlobPath, relativePath);
+        return fs.existsSync(filePath);
+    }
 }
 
 export default new BlobStorageService();

apps/server/src/services/consistency_checks.ts

@@ -524,7 +524,8 @@ class ConsistencyChecks {
                         JOIN blobs USING (blobId)
                         WHERE isDeleted = 0
                         AND isProtected = 0
-                        AND content IS NULL`,
+                        AND content IS NULL
+                        AND (contentLocation IS NULL OR contentLocation = 'internal')`,
                 ({ noteId, type, mime }) => {
                     if (this.autoFix) {
                         const note = becca.getNote(noteId);