#306

backend/app/services/material_file_sha256.rb

@@ -0,0 +1,25 @@
+require 'digest'
+
+class MaterialFileSha256
+  def self.from_blob blob
+    sha256 = blob.metadata['sha256']
+    return sha256 if sha256.present?
+
+    blob.open do |file|
+      sha256 = Digest::SHA256.file(file.path).hexdigest
+      blob.metadata['sha256'] = sha256
+      blob.save! if blob.changed?
+      sha256
+    end
+  end
+
+  def self.from_upload upload
+    tempfile = upload&.tempfile
+    return nil unless tempfile
+
+    tempfile.rewind
+    Digest::SHA256.file(tempfile.path).hexdigest.tap do
+      tempfile.rewind
+    end
+  end
+end