Cache if gem is indexed in Gemstash::Storage

[smellsblue]

This moves whether a gem is indexed into Gemstash::Storage so we don't need to do any DB queries when bundling with a Gemfile.lock.

This also combines a migration as described in #43.

Important note: There is now a small amount of file interaction inside a database transaction. I think it might be fine as it should be pretty minimal in an infrequent codepath, but it makes me uncomfortable enough to mention it here. It is nice that failed file operations would cause a DB rollback, but is this shortsighted in some way I'm not thinking of?

[pcarranza]

What about?

def save(content, properties: nil)
  save_content(content)
  save_properties(properties) unless properties.nil?
  self
end

def update_properties(data)
  load
  save_properties(@properties.merge(data))
  self
end

def save_content(content)
  store(content_filename, content)
  @content = content
end

def save_properties(properties)
  store(properties_filename, properties.to_yam)
  @properties = properties
end

def store(filename, content)
  FileUtils.mkpath(@folder) unless Dir.exist?(@folder)
  save_file(content_filename) { content }
  self
end

I have problems with flags 😅

[smellsblue]

👍 pushed an update

[pcarranza]

Regarding a rollback triggered by a saving failure, I don't think that it is an issue at all, I find it hard to think of a case when this will happen, and also if anyone is failing to save a yaml file probably has bigger issues than a rolled back transaction.

[smellsblue]

@pcarranza well, the rollback triggered by saving failure is kinda what I want (otherwise either the DB or the file system will be out of sync, neither case is good, especially with Gemstash::GemSource::PrivateSource using the storage to determine if the gem is indexed). What I don't like is interacting with anything but the database inside a database transaction... but I think it's fine and even desirable in this case... just wondering if there might be a better way :-)

[pcarranza]

I think it is fair enough. Not interacting would mean to do it with some kind of queuing system just registering the job and doing it later. Given the fact that this is such a small touch (a few bytes?) I wouldn't worry at all. It is quite an edge case.

[pcarranza]

👍 or