#306

backend/app/services/material_file_sha256.rb

@@ -1,15 +1,24 @@
 require 'digest'
 
 class MaterialFileSha256
-  def self.from_blob blob
+  def self.from_blob blob, allow_download: false
     sha256 = blob.metadata['sha256']
     return sha256 if sha256.present?
+    return nil unless allow_download
 
-    blob.open do |file|
-      sha256 = Digest::SHA256.file(file.path).hexdigest
-      blob.metadata['sha256'] = sha256
-      blob.save! if blob.changed?
-      sha256
+    begin
+      blob.open do |file|
+        sha256 = Digest::SHA256.file(file.path).hexdigest
+        blob.metadata['sha256'] = sha256
+        blob.save! if blob.changed?
+        sha256
+      end
+    rescue ActiveStorage::FileNotFoundError, ArgumentError => error
+      Rails.logger.warn(
+          "MaterialFileSha256.from_blob failed for blob_id=#{blob.id}: " \
+          "#{error.class}: #{error.message}",
+      )
+      nil
     end
   end