Contents

# encoding: utf-8

module RedisCopy
  # A Key emitter emits keys.
  # This is built to be an abstraction on top of
  # redis.keys('*') (implemented by RedisCopy::KeyEmitter::Default),
  # but should allow smarter implementations to be built that can handle
  # billion-key dbs without blocking on IO.
  module KeyEmitter
    def self.load(redis, ui, options = {})
      key_emitter = options.fetch(:key_emitter, :default)
      const_name = key_emitter.to_s.camelize
      require "redis-copy/key-emitter/#{key_emitter}" unless const_defined?(const_name)
      const_get(const_name).new(redis, ui, options)
    end

    # @param redis [Redis]
    # @param options [Hash<Symbol:String>]
    def initialize(redis, ui, options = {})
      @redis    = redis
      @ui       = ui
      @options  = options
    end

    # @return [Enumerable<String>]
    def keys
      return super if defined?(super)
      raise NotImplementedError
    end

    def to_s
      self.class.name.demodulize.humanize
    end

    # The default strategy blindly uses `redis.keys('*')`
    class Default
      include KeyEmitter

      def keys
        @ui.debug "REDIS: #{@redis.client.id} KEYS *"
        @redis.keys('*').to_enum
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
redis-copy-0.0.1	lib/redis-copy/key-emitter.rb