Reuse existing identical disk files for new attachments (#25215).

Patch by Jens Kraemer.

git-svn-id: http://svn.redmine.org/redmine/trunk@16458 e93f8b46-1217-0410-a6f0-8f06a7374b81

1 files changed, 19 insertions, 0 deletions

diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 1e4f731e7..8e8cc0ac1 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -56,6 +56,7 @@ class Attachment < ActiveRecord::Base
   before_create :files_to_final_location
   after_rollback :delete_from_disk, :on => :create
   after_commit :delete_from_disk, :on => :destroy
+  after_commit :reuse_existing_file_if_possible, :on => :create
 
   safe_attributes 'filename', 'content_type', 'description'
 
@@ -411,6 +412,24 @@ class Attachment < ActiveRecord::Base
 
   private
 
+  def reuse_existing_file_if_possible
+    with_lock do
+      if existing = Attachment
+                      .lock
+                      .where(digest: self.digest, filesize: self.filesize)
+                      .where('id <> ? and disk_filename <> ?',
+                             self.id, self.disk_filename)
+                      .first
+
+        original_diskfile = self.diskfile
+        self.update_columns disk_directory: existing.disk_directory,
+                            disk_filename: existing.disk_filename
+        File.delete(original_diskfile) if File.exist?(original_diskfile)
+      end
+    end
+  end
+
+
   # Physically deletes the file from the file system
   def delete_from_disk!
     if disk_filename.present? && File.exist?(diskfile)