Class: Moneta::Adapters::ActiveRecord

Inherits:
Object
  • Object
show all
Includes:
Defaults
Defined in:
lib/moneta/adapters/activerecord.rb

Overview

ActiveRecord as key/value stores

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Defaults

#[], #[]=, #close, #decrement, #features, #fetch, included, #supports?

Methods included from OptionSupport

#expires, #prefix, #raw, #with

Constructor Details

#initialize(options = {}) ⇒ ActiveRecord

Returns a new instance of ActiveRecord.

Parameters:

  • options (Hash) (defaults to: {})

Options Hash (options):

  • :table (String) — default: 'moneta' —

    Table name

  • :connection (Hash) —

    ActiveRecord connection configuration



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

def initialize(options = {})
  table = options[:table] || 'moneta'
  @table = self.class.tables[table] ||=
    begin
      c = Class.new(::ActiveRecord::Base)
      c.table_name = table
      c.primary_key = :k
      c
    end

  if options[:connection]
    begin
      @table.establish_connection(options[:connection])
    rescue
      tries ||= 0
      (tries += 1) < 3 ? retry : raise
    end
  end

  unless @table.table_exists?
    @table.connection.create_table(@table.table_name, :id => false) do |t|
      # Do not use binary columns (Issue #17)
      t.string :k, :null => false
      t.string :v
    end
    @table.connection.add_index(@table.table_name, :k, :unique => true)
  end
end

Instance Attribute Details

#table ⇒ Object (readonly) 



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# File 'lib/moneta/adapters/activerecord.rb', line 11

def table
  @table
end

Class Method Details

.tables ⇒ Object 



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# File 'lib/moneta/adapters/activerecord.rb', line 13

def self.tables
  @tables ||= {}
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/activerecord.rb', line 112

def clear(options = {})
  @table.delete_all
  self
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/activerecord.rb', line 99

def create(key, value, options = {})
  record = @table.new
  record.k = key
  record.v = value
  record.save
  true
rescue
  # FIXME: This catches too many errors
  # it should only catch a not-unique-exception
  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/activerecord.rb', line 72

def delete(key, options = {})
  if record = @table.where(:k => key).first
    record.destroy
    record.v
  end
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/activerecord.rb', line 80

def increment(key, amount = 1, options = {})
  @table.transaction do
    if record = @table.where(:k => key).lock.first
      value = Utils.to_int(record.v) + amount
      record.v = value.to_s
      record.save
      value
    elsif create(key, amount.to_s, options)
      amount
    else
      raise 'Concurrent modification'
    end
  end
rescue
  tries ||= 0
  (tries += 1) < 10 ? retry : raise
end

#key?(key, options = {}) ⇒ Boolean

Exists the value with key

Parameters:

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

Options Hash (options):

  • :expires (Integer) —

    Update expiration time (See Expires)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Boolean) 


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# File 'lib/moneta/adapters/activerecord.rb', line 50

def key?(key, options = {})
  !@table.where(:k => key).empty?
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)

  • Other (Object) —

    options as defined by the adapters or middleware

Returns:

  • (Object) —

    value



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# File 'lib/moneta/adapters/activerecord.rb', line 55

def load(key, options = {})
  record = @table.select(:v).where(:k => key).first
  record && record.v
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/activerecord.rb', line 61

def store(key, value, options = {})
  record = @table.select(:k).where(:k => key).first_or_initialize
  record.v = value
  record.save
  value
rescue
  tries ||= 0
  (tries += 1) < 10 ? retry : raise
end