Class: MemcachedWrapper

Inherits:
Memcached show all
Defined in:
lib/memcached_wrapper.rb,
lib/memcached_wrapper.rb

Overview

TODO add logging?

Constant Summary collapse

DEFAULTS = 
{ :servers => '127.0.0.1:11211' }

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ MemcachedWrapper

See Memcached#new for details.



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# File 'lib/memcached_wrapper.rb', line 32

def initialize(*args)
    opts = DEFAULTS.merge(args.last.is_a?(Hash) ? args.pop : {})

    if opts.respond_to?(:symbolize_keys!)
      opts.symbolize_keys!
    else
      opts = symbolize_keys(opts)
    end
    
    servers = Array(
      args.any? ? args.unshift : opts.delete(:servers)
    ).flatten.compact

    opts[:prefix_key] ||= "#{opts[:namespace]}:"

    @logger = opts[:logger]
    @debug  = opts[:debug]

    super(servers, opts)      
end

Instance Attribute Details

#default_ttl ⇒ Object (readonly)

Returns the value of attribute default_ttl.



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# File 'lib/memcached_wrapper.rb', line 29

def default_ttl
  @default_ttl
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/memcached_wrapper.rb', line 29

def logger
  @logger
end

Instance Method Details

#add(key, value, ttl = @default_ttl, raw = false) ⇒ Object

Wraps Memcached::Rails#add to return a text string - for cache money



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# File 'lib/memcached_wrapper.rb', line 71

def add(key, value, ttl=@default_ttl, raw=false)
  logger.debug("Memcached add: #{key.inspect}") if logger && @debug
  super(key, value, ttl, !raw)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  stored
rescue Memcached::NotStored
  logger.debug("Memcached miss: #{key.inspect}") if logger && @debug
  not_stored
rescue Memcached::Error
  log_error($!) if logger
  not_stored
end

#append(key, value) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 176

def append(key, value)
  logger.debug("Memcached append: #{key.inspect}") if logger && @debug
  super(key, value)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  stored
rescue Memcached::NotStored
  logger.debug("Memcached miss: #{key.inspect}") if logger && @debug
  not_stored
rescue Memcached::Error
  log_error($!) if logger
end

#cas(key, ttl = @default_ttl, raw = false, &block) ⇒ Object Also known as: compare_and_swap

Wraps Memcached#cas so that it doesn’t raise. Doesn’t set anything if no value is present.



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

def cas(key, ttl=@default_ttl, raw=false, &block)
  logger.debug("Memcached cas: #{key.inspect}") if logger && @debug
  super(key, ttl, !raw, &block)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  stored
rescue Memcached::NotFound
  logger.debug("Memcached miss: #{key.inspect}") if logger && @debug
rescue TypeError
  log_error($!) if logger
  delete(key)
  logger.debug("Memcached deleted: #{key.inspect}") if logger && @debug
rescue Memcached::Error
  if $!.is_a?(Memcached::ClientError)
    raise $!
  end
  log_error($!) if logger
end

#decr(*args) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 219

def decr(*args)
  super
rescue Memcached::NotFound
rescue Memcached::Error
  log_error($!) if logger
end

#delete(key) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 200

def delete(key)
  logger.debug("Memcached delete: #{key.inspect}") if logger && @debug
  super(key)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  deleted
rescue Memcached::NotFound
  logger.debug("Memcached miss: #{key.inspect}") if logger && @debug
  not_found
rescue Memcached::Error
  log_error($!) if logger
end

#fetch(key, expiry = 0, raw = false) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 117

def fetch(key, expiry = 0, raw = false)
  value = get(key, !raw)

  if value.nil? && block_given?
    value = yield
    add(key, value, expiry, !raw)
  end

  value
end

#get(key, raw = false) ⇒ Object Also known as: []

Wraps Memcached#get so that it doesn’t raise. This has the side-effect of preventing you from storing nil values.



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# File 'lib/memcached_wrapper.rb', line 99

def get(key, raw=false)
  logger.debug("Memcached get: #{key.inspect}") if logger && @debug
  value = super(key, !raw)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  value
rescue Memcached::NotFound
  logger.debug("Memcached miss: #{key.inspect}") if logger && @debug
  nil
rescue TypeError
  log_error($!) if logger
  delete(key)
  logger.debug("Memcached deleted: #{key.inspect}") if logger && @debug
  nil
rescue Memcached::Error
  log_error($!) if logger
  nil
end

#get_multi(*keys) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 147

def get_multi(*keys)
  keys.flatten!
  logger.debug("Memcached get_multi: #{keys.inspect}") if logger && @debug
  values = super(keys, true)
  logger.debug("Memcached hit: #{keys.inspect}") if logger && @debug
  values
rescue Memcached::NotFound
  logger.debug("Memcached miss: #{keys.inspect}") if logger && @debug
  {}
rescue TypeError
  log_error($!) if logger
  keys.each { |key| delete(key) }
  logger.debug("Memcached deleted: #{keys.inspect}") if logger && @debug
  {}
rescue Memcached::Error
  log_error($!) if logger
  {}
end

#get_server_for_key(key, options = {}) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 226

def get_server_for_key(key, options = {})
  server_by_key(key)
end

#incr(*args) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 212

def incr(*args)
  super
rescue Memcached::NotFound
rescue Memcached::Error
  log_error($!) if logger
end

#namespace ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 66

def namespace
  options[:prefix_key]
end

#prepend(key, value) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 188

def prepend(key, value)
  logger.debug("Memcached prepend: #{key.inspect}") if logger && @debug
  super(key, value)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  stored
rescue Memcached::NotStored
  logger.debug("Memcached miss: #{key.inspect}") if logger && @debug
  not_stored
rescue Memcached::Error
  log_error($!) if logger
end

#replace(key, value, ttl = @default_ttl, raw = false) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 84

def replace(key, value, ttl = @default_ttl, raw = false)
  logger.debug("Memcached replace: #{key.inspect}") if logger && @debug
  super(key, value, ttl, !raw)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  stored
rescue Memcached::NotStored
  logger.debug("Memcached miss: #{key.inspect}") if logger && @debug
  not_stored
rescue Memcached::Error
  log_error($!) if logger
  not_stored
end

#set(key, value, ttl = @default_ttl, raw = false) ⇒ Object Also known as: []= 



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# File 'lib/memcached_wrapper.rb', line 166

def set(key, value, ttl=@default_ttl, raw=false)
  logger.debug("Memcached set: #{key.inspect}") if logger && @debug
  super(key, value, ttl, !raw)
  logger.debug("Memcached hit: #{key.inspect}") if logger && @debug
  stored
rescue Memcached::Error
  log_error($!) if logger
  not_stored
end

#symbolize_keys(opts) ⇒ Object 



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# File 'lib/memcached_wrapper.rb', line 53

def symbolize_keys(opts)
  # Destructively convert all keys to symbols.
  if opts.kind_of?(Hash) && !opts.kind_of?(HashWithIndifferentAccess)
    opts.keys.each do |key|
      unless key.is_a?(Symbol)
        opts[key.to_sym] = opts[key]
        opts.delete(key)
      end
    end
  end
  opts
end