Class: Moneta::Adapters::MemcachedNative

Inherits:
Object
  • Object
show all
Includes:
Defaults, ExpiresSupport
Defined in:
lib/moneta/adapters/memcached/native.rb

Overview

Memcached backend (using gem memcached)

Instance Attribute Summary collapse

Attributes included from ExpiresSupport

#default_expires

Instance Method Summary collapse

Methods included from Defaults

#[], #[]=, #decrement, #each_key, #features, #fetch, #fetch_values, included, #key?, #merge!, #slice, #supports?, #update, #values_at

Methods included from OptionSupport

#expires, #prefix, #raw, #with

Constructor Details

#initialize(options = {}) ⇒ MemcachedNative

Returns a new instance of MemcachedNative.

Parameters:

  • options (Hash) (defaults to: {})

Options Hash (options):

  • :server (String) — default: '127.0.0.1:11211' —

    Memcached server

  • :namespace (String) —

    Key namespace

  • :expires (Integer) — default: 604800 —

    Default expiration time

  • :backend (::Memcached) —

    Use existing backend instance

  • Other (Object) —

    options passed to `Memcached#new`


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# File 'lib/moneta/adapters/memcached/native.rb', line 20

def initialize(options = {})
  server = options.delete(:server) || '127.0.0.1:11211'
  self.default_expires = options.delete(:expires)
  @backend = options[:backend] ||
    begin
      options.merge!(prefix_key: options.delete(:namespace)) if options[:namespace]
      # We don't want a limitation on the key charset. Therefore we use the binary protocol.
      # It is also faster.
      options[:binary_protocol] = true unless options.include?(:binary_protocol)
      ::Memcached.new(server, options)
    end
end

Instance Attribute Details

#backend ⇒ Object (readonly) 


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# File 'lib/moneta/adapters/memcached/native.rb', line 12

def backend
  @backend
end

Instance Method Details

#clear(options = {}) ⇒ void

This method returns an undefined value.

Clear all keys in this store

Parameters:

  • options (Hash) (defaults to: {}) 

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# File 'lib/moneta/adapters/memcached/native.rb', line 91

def clear(options = {})
  @backend.flush
  self
end

#close ⇒ Object

Explicitly close the store

Returns:

  • nil


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# File 'lib/moneta/adapters/memcached/native.rb', line 97

def close
  @backend.reset
  nil
end

#create(key, value, options = {}) ⇒ Boolean

Note:

Not every Moneta store implements this method, a NotImplementedError is raised if it is not supported.

Atomically sets a key to value if it's not set.

Parameters:

  • key (Object)
  • value (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :expires (Integer) —

    Update expiration time (See Expires)

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

Returns:

  • (Boolean) —

    key was set


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# File 'lib/moneta/adapters/memcached/native.rb', line 81

def create(key, value, options = {})
  expires = expires_value(options)
  Numeric === expires and expires = expires.to_i
  @backend.add(key, value, expires || 0, false)
  true
rescue ::Memcached::ConnectionDataExists
  false
end

#delete(key, options = {}) ⇒ Object

Delete the key from the store and return the current value

Parameters:

  • key (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Object) —

    current value


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# File 'lib/moneta/adapters/memcached/native.rb', line 57

def delete(key, options = {})
  value = @backend.get(key, false)
  @backend.delete(key)
  value
rescue ::Memcached::NotFound
end

#increment(key, amount = 1, options = {}) ⇒ Object

Note:

Not every Moneta store implements this method, a NotImplementedError is raised if it is not supported.

Atomically increment integer value with key

This method also accepts negative amounts.

Parameters:

  • key (Object)
  • amount (Integer) (defaults to: 1)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Object) —

    value from store


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# File 'lib/moneta/adapters/memcached/native.rb', line 65

def increment(key, amount = 1, options = {})
  result = if amount >= 0
    @backend.increment(key, amount)
  else
    @backend.decrement(key, -amount)
  end
  # HACK: Throw error if applied to invalid value
  # see https://github.com/evan/memcached/issues/110
  Utils.to_int((@backend.get(key, false) rescue nil)) if result == 0
  result
rescue ::Memcached::NotFound => ex
  retry unless create(key, amount.to_s, options)
  amount
end

#load(key, options = {}) ⇒ Object

Fetch value with key. Return nil if the key doesn't exist

Parameters:

  • key (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :expires (Integer) —

    Update expiration time (See Expires)

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • :sync (Boolean) —

    Synchronized load (Cache reloads from adapter, Daybreak syncs with file)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Object) —

    value


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# File 'lib/moneta/adapters/memcached/native.rb', line 34

def load(key, options = {})
  value = @backend.get(key, false)
  if value
    expires = expires_value(options, nil)
    unless expires.nil?
      Numeric === expires and expires = expires.to_i
      @backend.set(key, value, expires || 0, false)
    end
    value
  end
rescue ::Memcached::NotFound
end

#store(key, value, options = {}) ⇒ Object

Store value with key

Parameters:

  • key (Object)
  • value (Object)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :expires (Integer) —

    Set expiration time (See Expires)

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • value


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# File 'lib/moneta/adapters/memcached/native.rb', line 48

def store(key, value, options = {})
  # TTL must be Integer
  expires = expires_value(options)
  Numeric === expires and expires = expires.to_i
  @backend.set(key, value, expires || 0, false)
  value
end