Merge branch 'add-moneky-patch-for-using-stream-upload-with-carrierwave' into 'master'

Add a monkey patch of https://github.com/carrierwaveuploader/carrierwave/pull/2314

See merge request gitlab-org/gitlab-ce!19102

changelogs/unreleased/add-moneky-patch-for-using-stream-upload-with-carrierwave.yml

+---
+title: Fix CarrierWave reads local files into memoery when migrates to ObjectStorage
+merge_request: 19102
+author:
+type: performance

config/initializers/carrierwave_monkey_patch.rb

+# This fixes the problem https://gitlab.com/gitlab-org/gitlab-ce/issues/46182 that carrierwave eagerly loads upoloading files into memory
+# There is an PR https://github.com/carrierwaveuploader/carrierwave/pull/2314 which has the identical change.
+module CarrierWave
+  module Storage
+    class Fog < Abstract
+      class File
+        module MonkeyPatch
+          ##
+          # Read content of file from service
+          #
+          # === Returns
+          #
+          # [String] contents of file
+          def read
+            file_body = file.body
+
+            return if file_body.nil?
+            return file_body unless file_body.is_a?(::File)
+
+            # Fog::Storage::XXX::File#body could return the source file which was upoloaded to the remote server.
+            read_source_file(file_body) if ::File.exist?(file_body.path)
+
+            # If the source file doesn't exist, the remote content is read
+            @file = nil # rubocop:disable Gitlab/ModuleWithInstanceVariables
+            file.body
+          end
+
+          ##
+          # Write file to service
+          #
+          # === Returns
+          #
+          # [Boolean] true on success or raises error
+          def store(new_file)
+            if new_file.is_a?(self.class) # rubocop:disable Cop/LineBreakAroundConditionalBlock
+              new_file.copy_to(path)
+            else
+              fog_file = new_file.to_file
+              @content_type ||= new_file.content_type # rubocop:disable Gitlab/ModuleWithInstanceVariables
+              @file = directory.files.create({ # rubocop:disable Gitlab/ModuleWithInstanceVariables
+                :body         => fog_file ? fog_file : new_file.read, # rubocop:disable Style/HashSyntax
+                :content_type => @content_type, # rubocop:disable Style/HashSyntax,Gitlab/ModuleWithInstanceVariables
+                :key          => path, # rubocop:disable Style/HashSyntax
+                :public       => @uploader.fog_public # rubocop:disable Style/HashSyntax,Gitlab/ModuleWithInstanceVariables
+              }.merge(@uploader.fog_attributes)) # rubocop:disable Gitlab/ModuleWithInstanceVariables
+              fog_file.close if fog_file && !fog_file.closed?
+            end
+            true
+          end
+
+          private
+
+          def read_source_file(file_body)
+            return unless ::File.exist?(file_body.path)
+
+            begin
+              file_body = ::File.open(file_body.path) if file_body.closed? # Reopen if it's already closed
+              file_body.read
+            ensure
+              file_body.close
+            end
+          end
+        end
+
+        prepend MonkeyPatch
+      end
+    end
+  end
+end