Class: CoffeeTable::Cache

Inherits:
Object
  • Object
show all
Includes:
Utility
Defined in:
lib/coffee_table.rb

Instance Method Summary collapse

Methods included from Utility

#method_missing, #underscore

Constructor Details

#initialize(options = {}) ⇒ Cache

initialize for coffee_table. takes options to setup behaviour of cache



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# File 'lib/coffee_table.rb', line 19

def initialize(options={})
  @options = options

  default_enable_cache_to true
  default_redis_namespace_to :coffee_table
  default_redis_server_to "127.0.0.1"
  default_redis_port_to 6379
  default_redis_to nil
  default_ignore_code_changes_to false
  default_compress_content_to true
  default_compress_min_size_to 10240
  default_max_threads_to 5

  if !@options[:redis].nil?
    @redis = @options[:redis]
  elsif @options.has_key?(:redis_url)
    @redis = Redis.new({:url => @options[:redis_url]})
  else
    @redis = Redis.new({:server => @options[:redis_server], :port => @options[:redis_port]})
  end
  rufus_version = Gem::Version.new(Rufus::Scheduler::VERSION)
  if rufus_version >= Gem::Version.new('3.0.0')
    @scheduler = Rufus::Scheduler.new(:max_work_threads )
  else
    @scheduler = Rufus::Scheduler.start_new
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class CoffeeTable::Utility

Instance Method Details

#expire_all ⇒ Object 



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# File 'lib/coffee_table.rb', line 121

def expire_all
  keys.map{|key| expire_key(key)}
end

#expire_for(*objects) ⇒ Object 



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# File 'lib/coffee_table.rb', line 129

def expire_for(*objects)
  if defined? Rails
    perform_caching = Rails.application.configure do
      config.action_controller.perform_caching
    end
  else
    perform_caching = true
  end

  if perform_caching
    deleted_keys = []
    unless objects.count == 0
      keys.map{|k| CoffeeTable::Key.parse(k)}.each do |key|
        expire = true
        objects.each do |object|
          if object.class == String || object.class == Symbol
            unless key.has_element?(object)
              expire = false
            end
          elsif object.class == Class
            object_type = underscore(object.to_s)
            unless key.has_element_type?(object_type) || key.has_element_type?(ActiveSupport::Inflector.pluralize(object_type))
              expire = false
            end
          else
            object_type = underscore(object.class.to_s)
            unless key.has_element?("#{object_type.to_sym}[#{object.id}]") or key.has_element?(object_type)
              expire = false
            end
          end
        end
        if expire
          expire_key(key.to_s)
          deleted_keys << key
        end
      end
    end
    deleted_keys
  end
end

#expire_key(key_value) ⇒ Object 



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# File 'lib/coffee_table.rb', line 114

def expire_key(key_value)
  keys.map{|k| CoffeeTable::Key.parse(k)}.select{|key| key.has_element?(key_value) || key.to_s == key_value }.each do |key|
    @redis.del(key.to_s)
    @redis.srem "cache_keys", key.to_s
  end
end

#fetch(initial_key, *related_objects, &block) ⇒ Object Also known as: get_cache

Raises:



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# File 'lib/coffee_table.rb', line 48

def fetch(initial_key, *related_objects, &block)
  raise CoffeeTable::BlockMissingError, "No block given to generate cache from" unless block_given?

  # extract the options hash if it is present
  options = {}
  if related_objects[-1].instance_of? Hash
    options = related_objects[-1]
    related_objects = related_objects[0..-2]
  end

  # check objects are valid
  related_objects.flatten.map{|o| raise CoffeeTable::InvalidObjectError, "Objects passed in must have an id method or be a class" unless object_valid?(o)}

  if @options[:ignore_code_changes]
    block_key = ""
  else
    block_source = RubyVM::InstructionSequence.disasm(block.to_proc).to_s.gsub(/\(\s*\d+\)/, "").gsub(/^== disasm.*?$/, "")
    block_key = Digest::MD5.hexdigest(block_source)
  end

  flags = {}



  # if first related_object is integer or fixnum it is used as an expiry time for the cache object
  key = CoffeeTable::Key.new(initial_key, block_key, flags, related_objects)

  if @options[:enable_cache]
    if options.has_key?(:expiry)
      expiry = options[:expiry]
    else
      expiry = nil
    end

    @redis.sadd "cache_keys", key unless @redis.sismember "cache_keys", key.to_s
    if @redis.exists(key.to_s)
      if key.options[:compressed]
        result = marshal_value(@redis.get(key.to_s).gunzip)
      else
        result = marshal_value(@redis.get(key.to_s))
      end
    else
      result = yield

      compress_result = @options[:compress_content] && result.kind_of?(String) && result.length > @options[:compress_min_size]

      if compress_result
        key.add_flag(:compressed => true)
        @redis.set key.to_s, Marshal.dump(result.gzip)
      else
        @redis.set key.to_s, Marshal.dump(result)
      end

      unless expiry.nil?
        @redis.expire key.to_s, expiry
        @scheduler.in "#{expiry}s" do
          @redis.srem "cache_keys", key.to_s
        end
      end
    end
  else
    result = yield
  end
  result
end

#keys ⇒ Object 



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# File 'lib/coffee_table.rb', line 125

def keys
  @redis.smembers("cache_keys")
end