Class: Juno::Adapters::Cassandra

Inherits:
Base
  • Object
show all
Defined in:
lib/juno/adapters/cassandra.rb

Overview

Cassandra backend

Instance Method Summary collapse

Methods inherited from Base

#[], #[]=, #close, #fetch

Constructor Details

#initialize(options = {}) ⇒ Cassandra

Constructor

Options:

  • :keyspace - Cassandra keyspace (default ‘juno’)

  • :column_family - Cassandra column family (default ‘juno’)

  • :host - Server host name (default 127.0.0.1)

  • :port - Server port (default 9160)

Parameters:

  • options (Hash) (defaults to: {}) 


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# File 'lib/juno/adapters/cassandra.rb', line 20

def initialize(options = {})
  options[:host] ||= '127.0.0.1'
  options[:port] ||=  9160
  keyspace = (options[:keyspace] ||= 'juno')
  @cf = (options[:column_family] || 'juno').to_sym
  @client = ::Cassandra.new('system', "#{options[:host]}:#{options[:port]}")
  unless @client.keyspaces.include?(keyspace)
    cf_def = ::Cassandra::ColumnFamily.new(:keyspace => keyspace, :name => @cf.to_s)
    ks_def = ::Cassandra::Keyspace.new(:name => keyspace,
                                       :strategy_class => 'SimpleStrategy',
                                       :strategy_options => { 'replication_factor' => '1' },
                                       :replication_factor => 1,
                                       :cf_defs => [cf_def])
    # Wait for keyspace to be created (issue #24)
    10.times do
      begin
        @client.add_keyspace(ks_def)
      rescue Exception => ex
        puts "Cassandra: #{ex.message}"
      end
      break if @client.keyspaces.include?(keyspace)
      sleep 0.1
    end
  end
  @client.keyspace = keyspace
end

Instance Method Details

#clear(options = {}) ⇒ Object 



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# File 'lib/juno/adapters/cassandra.rb', line 74

def clear(options = {})
  @client.each_key(@cf) do |key|
    delete(key)
  end
  self
end

#delete(key, options = {}) ⇒ Object 



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# File 'lib/juno/adapters/cassandra.rb', line 62

def delete(key, options = {})
  if value = load(key, options)
    @client.remove(@cf, key)
    value
  end
end

#key?(key, options = {}) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/juno/adapters/cassandra.rb', line 47

def key?(key, options = {})
  @client.exists?(@cf, key)
end

#load(key, options = {}) ⇒ Object 



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# File 'lib/juno/adapters/cassandra.rb', line 51

def load(key, options = {})
  value = @client.get(@cf, key)
  if value
    if options.include?(:expires)
      store(key, value['value'], options)
    else
      value['value']
    end
  end
end

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



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# File 'lib/juno/adapters/cassandra.rb', line 69

def store(key, value, options = {})
  @client.insert(@cf, key, {'value' => value}, :ttl => options[:expires])
  value
end