I started using fog storage for a project. I do the most simple actions: upload an object, get the object, delete the object. My code looks something like this:
storage = get_storage(...) // S3 / OpenStack / ...
dir = storage.directories.get(bucket) # 1st request
if !dir.nil?
dir.files.create(key: key, body: body) # 2nd request
# or:
dir.files.get(key) # 2nd request
#or
file = dir.files.get(key) # 2nd request
if !file.nil?
file.destroy # 3rd request
end
end
In all cases there's a 1st step to get the directory, which does a request to the storage engine (it returns nil if the directory doesn't exists).
Then there's another step to do whatever I'd like to do (in case of delete there's even a 3rd step in the middle).
However if I look at let's say the Amazon S3 API, it's clear that deleting an object doesn't need 3 requests to amazon.
Is there a way to use fog but make it do less requests to the storage provider?
I think this was already answered on the mailing list, but if you use #new on directories/files it will give you just a local reference (vs #get which does a lookup). That should get you what you want, though it may raise errors if the file or directory does not exist.
Something like this:
storage = get_storage(...) // S3 / OpenStack / ...
dir = storage.directories.new(key: bucket)
dir.files.create(key: key, body: body) # 1st request
# or:
dir.files.get(key) # 1st request
#or
file = dir.files.new(key)
if !file.nil?
file.destroy # 1st request
end
Working in this way should allow any of the 3 modalities to work in a single request, but may result in errors if the bucket does not exist (as trying to add a file to non-existent bucket is an error). So it is more efficient, but would need different error handling. Conversely, you can make the extra requests if you need to be sure.