class Sprockets::Cache::FileStore


environment.cache = Sprockets::Cache::FileStore.new(“tmp/sprockets”)
A simple file system cache store.

def [](key)

Lookup value in cache 
def [](key)
  pathname = path_for(key)
  pathname.exist? ? pathname.open('rb') { |f| Marshal.load(f) } : nil
end

def []=(key, value)

Save value to cache 
def []=(key, value)
  path_for(key).open('w') { |f| Marshal.dump(value, f)}
  value
end

def initialize(root) 

def initialize(root)
  @root = Pathname.new(root)
  # Ensure directory exists
  FileUtils.mkdir_p @root
end

def path_for(key)

safe hex.
The key may include some funky characters so hash it into

Returns path for cache key. 
def path_for(key)
  @root.join(::Digest::MD5.hexdigest(key))
end