Tim's cache engine code for his other app It interacts directly with memcache It is the rails side of the php caching engine

speed.rb

# frozen_string_literal: true

module Speed

  PAGE_UPDATES = 'SPcstat:all_updates'
  VERSION_NAME = "mv|#{Rails.env}"

  # the master version increments the 'decimal' portion
  # each day (using julian day)
  # this automatically invalidates the cache at least once daily
  def self.master_version
    format("#{init_counter(VERSION_NAME)}.%03d", Date.current.yday)
  end

  def self.bump_master_version
    $memcache.incr(VERSION_NAME) ||
      (master_version and $memcache.incr(VERSION_NAME))
  end

  def self.model_name(model)
    "#{general_name}:#{model.class.table_name}"
  end

  def self.general_name
    "#{master_version}upgen:GENERAL:#{User.host}"
  end

  def self.model_version(model)
    init_counter model_name(model)
  end

  def self.general_version
    init_counter general_name
  end

  def self.init_counter(counter)
    # create the counter and start at 1 if it does not exist
    $memcache.incr counter, 0, 0, 1
  end

  def self.page_name
    "#{general_name}#{PAGE_UPDATES}"
  end

  def self.bump_general
    $memcache.incr page_name
    general = $memcache.incr general_name
    return general if general

    general_version
    $memcache.incr page_name
    $memcache.incr general_name
  end

  def self.bump_model(model)
    cached_incr = $memcache.incr model_name(model)
    unless cached_incr
      model_version(model)
      cached_incr = $memcache.incr model_name(model)
    end
    bump_general
    cached_incr
  end
end