Retry file conversion in case of DB connection issues

Fix CODEOCEAN-RZ

app/controllers/concerns/file_conversion.rb

@@ -4,42 +4,53 @@ module FileConversion
   private
 
   def convert_files_json_to_files(files_json)
-    # Return an empty list of files and directories if the files_json is nil
-    return [[], []] if files_json.blank?
+    retry_block do
+      # Return an empty list of files and directories if the files_json is nil
+      return [[], []] if files_json.blank?
 
-    directories = []
-    files = files_json['files'].filter_map do |file|
-      # entryType: `-` describes a regular file, `d` a directory. See `info ls` for others
-      directories.push(file['name']) if file['entryType'] == 'd'
-      next unless file['entryType'] == '-'
+      directories = []
+      files = files_json['files'].filter_map do |file|
+        # entryType: `-` describes a regular file, `d` a directory. See `info ls` for others
+        directories.push(file['name']) if file['entryType'] == 'd'
+        next unless file['entryType'] == '-'
 
-      file['extension'] = File.extname(file['name'])
-      file
+        file['extension'] = File.extname(file['name'])
+        file
+      end
+
+      # Optimize SQL queries: We are first fetching all required file types from the database.
+      # Then, we store them in a hash, so that we can access them by using their file extension.
+      file_types = {}
+      FileType.where(file_extension: files.pluck('extension')).each do |file_type|
+        file_types[file_type.file_extension] = file_type
+      end
+
+      files.map! do |file|
+        CodeOcean::File.new(
+          name: File.basename(file['name'], file['extension']),
+          path: File.dirname(file['name']).sub(%r{^(?>\./|\.)}, '').presence,
+          size: file['size'],
+          owner: file['owner'],
+          group: file['group'],
+          permissions: file['permissions'],
+          updated_at: file['modificationTime'],
+          file_type: file_types[file['extension']] || FileType.new(file_extension: file['extension'])
+        )
+      end
+      [augment_files_for_download(files), directories]
     end
-
-    # Optimize SQL queries: We are first fetching all required file types from the database.
-    # Then, we store them in a hash, so that we can access them by using their file extension.
-    file_types = {}
-    FileType.where(file_extension: files.pluck('extension')).each do |file_type|
-      file_types[file_type.file_extension] = file_type
-    end
-
-    files.map! do |file|
-      CodeOcean::File.new(
-        name: File.basename(file['name'], file['extension']),
-        path: File.dirname(file['name']).sub(%r{^(?>\./|\.)}, '').presence,
-        size: file['size'],
-        owner: file['owner'],
-        group: file['group'],
-        permissions: file['permissions'],
-        updated_at: file['modificationTime'],
-        file_type: file_types[file['extension']] || FileType.new(file_extension: file['extension'])
-      )
-    end
-    [augment_files_for_download(files), directories]
   end
 
   def augment_files_for_download(files)
     raise NotImplementedError
   end
+
+  def retry_block(count: 1)
+    yield
+  rescue ActiveRecord::StatementInvalid => e
+    count -= 1
+    retry if count.positive?
+
+    raise e
+  end
 end