Class: DTAS::Mcache

Inherits:
Object
  • Object
show all
Defined in:
lib/dtas/mcache.rb

Instance Method Summary collapse

Constructor Details

#initialize(shift = 8, ttl = 60) ⇒ Mcache 



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# File 'lib/dtas/mcache.rb', line 8

def initialize(shift = 8, ttl = 60)
  @mask = (1 << shift) - 1
  @ttl = ttl
  @tbl = []
end

Instance Method Details

#lookup(infile) ⇒ Object 



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# File 'lib/dtas/mcache.rb', line 14

def lookup(infile)
  bucket = infile.hash & @mask
  st = nil
  if cur = @tbl[bucket]
    if cur[:infile] == infile && (DTAS.now - cur[:btime]) < @ttl
      begin
        st = File.stat(infile)
        return cur if cur[:ctime] == st.ctime
      rescue
      end
    end
  end
  return unless block_given?
  @tbl[bucket] = begin
    cur = cur ? cur.clear : {}
    begin
      st ||= File.stat(infile)
      cur[:ctime] = st.ctime
    rescue
      return
    end
    if ret = yield(infile, cur)
      ret[:infile] = infile.frozen? ? infile : -(infile.dup)
      ret[:btime] = DTAS.now
    end
    ret
  end
end