Carrierwave uncompress RAR file after upload - ruby-on-rails

Question

I'm actually looking for advices more than pure coding answers on how to uncompress RAR/ZIP file after upload while keeping a maximum rate of data integrity.
Here is my problem : my application's users are uploading files generated by Adobe Edge (we are using it for animated ads) which are in RAR format. To upload the file, it was really trivial. Here is my uploader :
class MediaUploader < CarrierWave::Uploader::Base
storage :file
def store_dir
"uploads/#{ model.class.to_s.underscore }/#{ mounted_as }/#{ ScatterSwap.hash(model.id) }"
end
def extension_white_list
%w(jpg jpeg gif png rar zip)
end
def filename
"#{ secure_token }.#{ file.extension }" if original_filename.present?
end
protected
def secure_token
var = :"##{ mounted_as }_secure_token"
model.instance_variable_get(var) or model.instance_variable_set(var, SecureRandom.uuid)
end
end
Now, in my case, the RAR file is not actually the one I'll be using. What I need are the files contain inside the archive. Those files generally looks like that :
- edge_includes
|
- images
|
- js
|
| ADS_1234_988x160_edge.js
| ADS_1234_988x160_edgeActions.js
| ADS_1234_988x160.an
| ADS_1234_988x160.html
From the above example, I need to store the reference to ADS_1234_988x160.html file within the database.
For this purpose, I was going to use Carrierwave callbacks in order to :
after :store, :uncompress_and_update_reference
def uncompress_and_update_reference(file)
# uncompress and update reference
end
Uncompress the archive (probably using rubyzip)
Get the path to ADS_1234_988x160.html
Update the reference inside the database
Is there any better way to handle it? How to handle failure or network errors? Any ideas are welcome.

Answer 1

I had similar problem: zip is uploaded but it should not be stored, only unzipped content. I solved it by implementing dedicated storage. Something like:
class MyStorage
class App < CarrierWave::Storage::Abstract
def store!(file)
# invoked when file is moved from cache into store
# unzip and update db here
end
def retrieve!(identifier)
MyZipFile.new(identifier)
end
end
end
class MyZipFile
def initialize(identifier)
#identifier = identifier
end
def path
file.path
end
def delete
# delete unzipped files
end
def file
#file ||= zip_file
end
def zip_file
# create zip file somewhere in tmp dir
end
end
# in uploader file
storage MyStorage
storage :my_storage
If symbol is used than it need to be defined in carrierwave config:
CarrierWave.configure do |config|
config.storage_engines.merge!(my_storage: 'MyStorage')
end